// https://d3js.org Version 4.13.0. Copyright 2018 Mike Bostock.
(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
        typeof define === 'function' && define.amd ? define(['exports'], factory) :
            (factory((global.d3 = global.d3 || {})));
}(this, (function (exports) { 'use strict';

    var version = "4.13.0";

    function ascending(a, b) {
        return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
    }

    function bisector(compare) {
        if (compare.length === 1) compare = ascendingComparator(compare);
        return {
            left: function(a, x, lo, hi) {
                if (lo == null) lo = 0;
                if (hi == null) hi = a.length;
                while (lo < hi) {
                    var mid = lo + hi >>> 1;
                    if (compare(a[mid], x) < 0) lo = mid + 1;
                    else hi = mid;
                }
                return lo;
            },
            right: function(a, x, lo, hi) {
                if (lo == null) lo = 0;
                if (hi == null) hi = a.length;
                while (lo < hi) {
                    var mid = lo + hi >>> 1;
                    if (compare(a[mid], x) > 0) hi = mid;
                    else lo = mid + 1;
                }
                return lo;
            }
        };
    }

    function ascendingComparator(f) {
        return function(d, x) {
            return ascending(f(d), x);
        };
    }

    var ascendingBisect = bisector(ascending);
    var bisectRight = ascendingBisect.right;
    var bisectLeft = ascendingBisect.left;

    function pairs(array, f) {
        if (f == null) f = pair;
        var i = 0, n = array.length - 1, p = array[0], pairs = new Array(n < 0 ? 0 : n);
        while (i < n) pairs[i] = f(p, p = array[++i]);
        return pairs;
    }

    function pair(a, b) {
        return [a, b];
    }

    function cross(values0, values1, reduce) {
        var n0 = values0.length,
            n1 = values1.length,
            values = new Array(n0 * n1),
            i0,
            i1,
            i,
            value0;

        if (reduce == null) reduce = pair;

        for (i0 = i = 0; i0 < n0; ++i0) {
            for (value0 = values0[i0], i1 = 0; i1 < n1; ++i1, ++i) {
                values[i] = reduce(value0, values1[i1]);
            }
        }

        return values;
    }

    function descending(a, b) {
        return b < a ? -1 : b > a ? 1 : b >= a ? 0 : NaN;
    }

    function number(x) {
        return x === null ? NaN : +x;
    }

    function variance(values, valueof) {
        var n = values.length,
            m = 0,
            i = -1,
            mean = 0,
            value,
            delta,
            sum = 0;

        if (valueof == null) {
            while (++i < n) {
                if (!isNaN(value = number(values[i]))) {
                    delta = value - mean;
                    mean += delta / ++m;
                    sum += delta * (value - mean);
                }
            }
        }

        else {
            while (++i < n) {
                if (!isNaN(value = number(valueof(values[i], i, values)))) {
                    delta = value - mean;
                    mean += delta / ++m;
                    sum += delta * (value - mean);
                }
            }
        }

        if (m > 1) return sum / (m - 1);
    }

    function deviation(array, f) {
        var v = variance(array, f);
        return v ? Math.sqrt(v) : v;
    }

    function extent(values, valueof) {
        var n = values.length,
            i = -1,
            value,
            min,
            max;

        if (valueof == null) {
            while (++i < n) { // Find the first comparable value.
                if ((value = values[i]) != null && value >= value) {
                    min = max = value;
                    while (++i < n) { // Compare the remaining values.
                        if ((value = values[i]) != null) {
                            if (min > value) min = value;
                            if (max < value) max = value;
                        }
                    }
                }
            }
        }

        else {
            while (++i < n) { // Find the first comparable value.
                if ((value = valueof(values[i], i, values)) != null && value >= value) {
                    min = max = value;
                    while (++i < n) { // Compare the remaining values.
                        if ((value = valueof(values[i], i, values)) != null) {
                            if (min > value) min = value;
                            if (max < value) max = value;
                        }
                    }
                }
            }
        }

        return [min, max];
    }

    var array = Array.prototype;

    var slice = array.slice;
    var map = array.map;

    function constant(x) {
        return function() {
            return x;
        };
    }

    function identity(x) {
        return x;
    }

    function sequence(start, stop, step) {
        start = +start, stop = +stop, step = (n = arguments.length) < 2 ? (stop = start, start = 0, 1) : n < 3 ? 1 : +step;

        var i = -1,
            n = Math.max(0, Math.ceil((stop - start) / step)) | 0,
            range = new Array(n);

        while (++i < n) {
            range[i] = start + i * step;
        }

        return range;
    }

    var e10 = Math.sqrt(50);
    var e5 = Math.sqrt(10);
    var e2 = Math.sqrt(2);

    function ticks(start, stop, count) {
        var reverse,
            i = -1,
            n,
            ticks,
            step;

        stop = +stop, start = +start, count = +count;
        if (start === stop && count > 0) return [start];
        if (reverse = stop < start) n = start, start = stop, stop = n;
        if ((step = tickIncrement(start, stop, count)) === 0 || !isFinite(step)) return [];

        if (step > 0) {
            start = Math.ceil(start / step);
            stop = Math.floor(stop / step);
            ticks = new Array(n = Math.ceil(stop - start + 1));
            while (++i < n) ticks[i] = (start + i) * step;
        } else {
            start = Math.floor(start * step);
            stop = Math.ceil(stop * step);
            ticks = new Array(n = Math.ceil(start - stop + 1));
            while (++i < n) ticks[i] = (start - i) / step;
        }

        if (reverse) ticks.reverse();

        return ticks;
    }

    function tickIncrement(start, stop, count) {
        var step = (stop - start) / Math.max(0, count),
            power = Math.floor(Math.log(step) / Math.LN10),
            error = step / Math.pow(10, power);
        return power >= 0
            ? (error >= e10 ? 10 : error >= e5 ? 5 : error >= e2 ? 2 : 1) * Math.pow(10, power)
            : -Math.pow(10, -power) / (error >= e10 ? 10 : error >= e5 ? 5 : error >= e2 ? 2 : 1);
    }

    function tickStep(start, stop, count) {
        var step0 = Math.abs(stop - start) / Math.max(0, count),
            step1 = Math.pow(10, Math.floor(Math.log(step0) / Math.LN10)),
            error = step0 / step1;
        if (error >= e10) step1 *= 10;
        else if (error >= e5) step1 *= 5;
        else if (error >= e2) step1 *= 2;
        return stop < start ? -step1 : step1;
    }

    function sturges(values) {
        return Math.ceil(Math.log(values.length) / Math.LN2) + 1;
    }

    function histogram() {
        var value = identity,
            domain = extent,
            threshold = sturges;

        function histogram(data) {
            var i,
                n = data.length,
                x,
                values = new Array(n);

            for (i = 0; i < n; ++i) {
                values[i] = value(data[i], i, data);
            }

            var xz = domain(values),
                x0 = xz[0],
                x1 = xz[1],
                tz = threshold(values, x0, x1);

            // Convert number of thresholds into uniform thresholds.
            if (!Array.isArray(tz)) {
                tz = tickStep(x0, x1, tz);
                tz = sequence(Math.ceil(x0 / tz) * tz, Math.floor(x1 / tz) * tz, tz); // exclusive
            }

            // Remove any thresholds outside the domain.
            var m = tz.length;
            while (tz[0] <= x0) tz.shift(), --m;
            while (tz[m - 1] > x1) tz.pop(), --m;

            var bins = new Array(m + 1),
                bin;

            // Initialize bins.
            for (i = 0; i <= m; ++i) {
                bin = bins[i] = [];
                bin.x0 = i > 0 ? tz[i - 1] : x0;
                bin.x1 = i < m ? tz[i] : x1;
            }

            // Assign data to bins by value, ignoring any outside the domain.
            for (i = 0; i < n; ++i) {
                x = values[i];
                if (x0 <= x && x <= x1) {
                    bins[bisectRight(tz, x, 0, m)].push(data[i]);
                }
            }

            return bins;
        }

        histogram.value = function(_) {
            return arguments.length ? (value = typeof _ === "function" ? _ : constant(_), histogram) : value;
        };

        histogram.domain = function(_) {
            return arguments.length ? (domain = typeof _ === "function" ? _ : constant([_[0], _[1]]), histogram) : domain;
        };

        histogram.thresholds = function(_) {
            return arguments.length ? (threshold = typeof _ === "function" ? _ : Array.isArray(_) ? constant(slice.call(_)) : constant(_), histogram) : threshold;
        };

        return histogram;
    }

    function threshold(values, p, valueof) {
        if (valueof == null) valueof = number;
        if (!(n = values.length)) return;
        if ((p = +p) <= 0 || n < 2) return +valueof(values[0], 0, values);
        if (p >= 1) return +valueof(values[n - 1], n - 1, values);
        var n,
            i = (n - 1) * p,
            i0 = Math.floor(i),
            value0 = +valueof(values[i0], i0, values),
            value1 = +valueof(values[i0 + 1], i0 + 1, values);
        return value0 + (value1 - value0) * (i - i0);
    }

    function freedmanDiaconis(values, min, max) {
        values = map.call(values, number).sort(ascending);
        return Math.ceil((max - min) / (2 * (threshold(values, 0.75) - threshold(values, 0.25)) * Math.pow(values.length, -1 / 3)));
    }

    function scott(values, min, max) {
        return Math.ceil((max - min) / (3.5 * deviation(values) * Math.pow(values.length, -1 / 3)));
    }

    function max(values, valueof) {
        var n = values.length,
            i = -1,
            value,
            max;

        if (valueof == null) {
            while (++i < n) { // Find the first comparable value.
                if ((value = values[i]) != null && value >= value) {
                    max = value;
                    while (++i < n) { // Compare the remaining values.
                        if ((value = values[i]) != null && value > max) {
                            max = value;
                        }
                    }
                }
            }
        }

        else {
            while (++i < n) { // Find the first comparable value.
                if ((value = valueof(values[i], i, values)) != null && value >= value) {
                    max = value;
                    while (++i < n) { // Compare the remaining values.
                        if ((value = valueof(values[i], i, values)) != null && value > max) {
                            max = value;
                        }
                    }
                }
            }
        }

        return max;
    }

    function mean(values, valueof) {
        var n = values.length,
            m = n,
            i = -1,
            value,
            sum = 0;

        if (valueof == null) {
            while (++i < n) {
                if (!isNaN(value = number(values[i]))) sum += value;
                else --m;
            }
        }

        else {
            while (++i < n) {
                if (!isNaN(value = number(valueof(values[i], i, values)))) sum += value;
                else --m;
            }
        }

        if (m) return sum / m;
    }

    function median(values, valueof) {
        var n = values.length,
            i = -1,
            value,
            numbers = [];

        if (valueof == null) {
            while (++i < n) {
                if (!isNaN(value = number(values[i]))) {
                    numbers.push(value);
                }
            }
        }

        else {
            while (++i < n) {
                if (!isNaN(value = number(valueof(values[i], i, values)))) {
                    numbers.push(value);
                }
            }
        }

        return threshold(numbers.sort(ascending), 0.5);
    }

    function merge(arrays) {
        var n = arrays.length,
            m,
            i = -1,
            j = 0,
            merged,
            array;

        while (++i < n) j += arrays[i].length;
        merged = new Array(j);

        while (--n >= 0) {
            array = arrays[n];
            m = array.length;
            while (--m >= 0) {
                merged[--j] = array[m];
            }
        }

        return merged;
    }

    function min(values, valueof) {
        var n = values.length,
            i = -1,
            value,
            min;

        if (valueof == null) {
            while (++i < n) { // Find the first comparable value.
                if ((value = values[i]) != null && value >= value) {
                    min = value;
                    while (++i < n) { // Compare the remaining values.
                        if ((value = values[i]) != null && min > value) {
                            min = value;
                        }
                    }
                }
            }
        }

        else {
            while (++i < n) { // Find the first comparable value.
                if ((value = valueof(values[i], i, values)) != null && value >= value) {
                    min = value;
                    while (++i < n) { // Compare the remaining values.
                        if ((value = valueof(values[i], i, values)) != null && min > value) {
                            min = value;
                        }
                    }
                }
            }
        }

        return min;
    }

    function permute(array, indexes) {
        var i = indexes.length, permutes = new Array(i);
        while (i--) permutes[i] = array[indexes[i]];
        return permutes;
    }

    function scan(values, compare) {
        if (!(n = values.length)) return;
        var n,
            i = 0,
            j = 0,
            xi,
            xj = values[j];

        if (compare == null) compare = ascending;

        while (++i < n) {
            if (compare(xi = values[i], xj) < 0 || compare(xj, xj) !== 0) {
                xj = xi, j = i;
            }
        }

        if (compare(xj, xj) === 0) return j;
    }

    function shuffle(array, i0, i1) {
        var m = (i1 == null ? array.length : i1) - (i0 = i0 == null ? 0 : +i0),
            t,
            i;

        while (m) {
            i = Math.random() * m-- | 0;
            t = array[m + i0];
            array[m + i0] = array[i + i0];
            array[i + i0] = t;
        }

        return array;
    }

    function sum(values, valueof) {
        var n = values.length,
            i = -1,
            value,
            sum = 0;

        if (valueof == null) {
            while (++i < n) {
                if (value = +values[i]) sum += value; // Note: zero and null are equivalent.
            }
        }

        else {
            while (++i < n) {
                if (value = +valueof(values[i], i, values)) sum += value;
            }
        }

        return sum;
    }

    function transpose(matrix) {
        if (!(n = matrix.length)) return [];
        for (var i = -1, m = min(matrix, length), transpose = new Array(m); ++i < m;) {
            for (var j = -1, n, row = transpose[i] = new Array(n); ++j < n;) {
                row[j] = matrix[j][i];
            }
        }
        return transpose;
    }

    function length(d) {
        return d.length;
    }

    function zip() {
        return transpose(arguments);
    }

    var slice$1 = Array.prototype.slice;

    function identity$1(x) {
        return x;
    }

    var top = 1;
    var right = 2;
    var bottom = 3;
    var left = 4;
    var epsilon = 1e-6;

    function translateX(x) {
        return "translate(" + (x + 0.5) + ",0)";
    }

    function translateY(y) {
        return "translate(0," + (y + 0.5) + ")";
    }

    function number$1(scale) {
        return function(d) {
            return +scale(d);
        };
    }

    function center(scale) {
        var offset = Math.max(0, scale.bandwidth() - 1) / 2; // Adjust for 0.5px offset.
        if (scale.round()) offset = Math.round(offset);
        return function(d) {
            return +scale(d) + offset;
        };
    }

    function entering() {
        return !this.__axis;
    }

    function axis(orient, scale) {
        var tickArguments = [],
            tickValues = null,
            tickFormat = null,
            tickSizeInner = 6,
            tickSizeOuter = 6,
            tickPadding = 3,
            k = orient === top || orient === left ? -1 : 1,
            x = orient === left || orient === right ? "x" : "y",
            transform = orient === top || orient === bottom ? translateX : translateY;

        function axis(context) {
            var values = tickValues == null ? (scale.ticks ? scale.ticks.apply(scale, tickArguments) : scale.domain()) : tickValues,
                format = tickFormat == null ? (scale.tickFormat ? scale.tickFormat.apply(scale, tickArguments) : identity$1) : tickFormat,
                spacing = Math.max(tickSizeInner, 0) + tickPadding,
                range = scale.range(),
                range0 = +range[0] + 0.5,
                range1 = +range[range.length - 1] + 0.5,
                position = (scale.bandwidth ? center : number$1)(scale.copy()),
                selection = context.selection ? context.selection() : context,
                path = selection.selectAll(".domain").data([null]),
                tick = selection.selectAll(".tick").data(values, scale).order(),
                tickExit = tick.exit(),
                tickEnter = tick.enter().append("g").attr("class", "tick"),
                line = tick.select("line"),
                text = tick.select("text");

            path = path.merge(path.enter().insert("path", ".tick")
                .attr("class", "domain")
                .attr("stroke", "#000"));

            tick = tick.merge(tickEnter);

            line = line.merge(tickEnter.append("line")
                .attr("stroke", "#000")
                .attr(x + "2", k * tickSizeInner));

            text = text.merge(tickEnter.append("text")
                .attr("fill", "#000")
                .attr(x, k * spacing)
                .attr("dy", orient === top ? "0em" : orient === bottom ? "0.71em" : "0.32em"));

            if (context !== selection) {
                path = path.transition(context);
                tick = tick.transition(context);
                line = line.transition(context);
                text = text.transition(context);

                tickExit = tickExit.transition(context)
                    .attr("opacity", epsilon)
                    .attr("transform", function(d) { return isFinite(d = position(d)) ? transform(d) : this.getAttribute("transform"); });

                tickEnter
                    .attr("opacity", epsilon)
                    .attr("transform", function(d) { var p = this.parentNode.__axis; return transform(p && isFinite(p = p(d)) ? p : position(d)); });
            }

            tickExit.remove();

            path
                .attr("d", orient === left || orient == right
                    ? "M" + k * tickSizeOuter + "," + range0 + "H0.5V" + range1 + "H" + k * tickSizeOuter
                    : "M" + range0 + "," + k * tickSizeOuter + "V0.5H" + range1 + "V" + k * tickSizeOuter);

            tick
                .attr("opacity", 1)
                .attr("transform", function(d) { return transform(position(d)); });

            line
                .attr(x + "2", k * tickSizeInner);

            text
                .attr(x, k * spacing)
                .text(format);

            selection.filter(entering)
                .attr("fill", "none")
                .attr("font-size", 10)
                .attr("font-family", "sans-serif")
                .attr("text-anchor", orient === right ? "start" : orient === left ? "end" : "middle");

            selection
                .each(function() { this.__axis = position; });
        }

        axis.scale = function(_) {
            return arguments.length ? (scale = _, axis) : scale;
        };

        axis.ticks = function() {
            return tickArguments = slice$1.call(arguments), axis;
        };

        axis.tickArguments = function(_) {
            return arguments.length ? (tickArguments = _ == null ? [] : slice$1.call(_), axis) : tickArguments.slice();
        };

        axis.tickValues = function(_) {
            return arguments.length ? (tickValues = _ == null ? null : slice$1.call(_), axis) : tickValues && tickValues.slice();
        };

        axis.tickFormat = function(_) {
            return arguments.length ? (tickFormat = _, axis) : tickFormat;
        };

        axis.tickSize = function(_) {
            return arguments.length ? (tickSizeInner = tickSizeOuter = +_, axis) : tickSizeInner;
        };

        axis.tickSizeInner = function(_) {
            return arguments.length ? (tickSizeInner = +_, axis) : tickSizeInner;
        };

        axis.tickSizeOuter = function(_) {
            return arguments.length ? (tickSizeOuter = +_, axis) : tickSizeOuter;
        };

        axis.tickPadding = function(_) {
            return arguments.length ? (tickPadding = +_, axis) : tickPadding;
        };

        return axis;
    }

    function axisTop(scale) {
        return axis(top, scale);
    }

    function axisRight(scale) {
        return axis(right, scale);
    }

    function axisBottom(scale) {
        return axis(bottom, scale);
    }

    function axisLeft(scale) {
        return axis(left, scale);
    }

    var noop = {value: function() {}};

    function dispatch() {
        for (var i = 0, n = arguments.length, _ = {}, t; i < n; ++i) {
            if (!(t = arguments[i] + "") || (t in _)) throw new Error("illegal type: " + t);
            _[t] = [];
        }
        return new Dispatch(_);
    }

    function Dispatch(_) {
        this._ = _;
    }

    function parseTypenames(typenames, types) {
        return typenames.trim().split(/^|\s+/).map(function(t) {
            var name = "", i = t.indexOf(".");
            if (i >= 0) name = t.slice(i + 1), t = t.slice(0, i);
            if (t && !types.hasOwnProperty(t)) throw new Error("unknown type: " + t);
            return {type: t, name: name};
        });
    }

    Dispatch.prototype = dispatch.prototype = {
        constructor: Dispatch,
        on: function(typename, callback) {
            var _ = this._,
                T = parseTypenames(typename + "", _),
                t,
                i = -1,
                n = T.length;

            // If no callback was specified, return the callback of the given type and name.
            if (arguments.length < 2) {
                while (++i < n) if ((t = (typename = T[i]).type) && (t = get(_[t], typename.name))) return t;
                return;
            }

            // If a type was specified, set the callback for the given type and name.
            // Otherwise, if a null callback was specified, remove callbacks of the given name.
            if (callback != null && typeof callback !== "function") throw new Error("invalid callback: " + callback);
            while (++i < n) {
                if (t = (typename = T[i]).type) _[t] = set(_[t], typename.name, callback);
                else if (callback == null) for (t in _) _[t] = set(_[t], typename.name, null);
            }

            return this;
        },
        copy: function() {
            var copy = {}, _ = this._;
            for (var t in _) copy[t] = _[t].slice();
            return new Dispatch(copy);
        },
        call: function(type, that) {
            if ((n = arguments.length - 2) > 0) for (var args = new Array(n), i = 0, n, t; i < n; ++i) args[i] = arguments[i + 2];
            if (!this._.hasOwnProperty(type)) throw new Error("unknown type: " + type);
            for (t = this._[type], i = 0, n = t.length; i < n; ++i) t[i].value.apply(that, args);
        },
        apply: function(type, that, args) {
            if (!this._.hasOwnProperty(type)) throw new Error("unknown type: " + type);
            for (var t = this._[type], i = 0, n = t.length; i < n; ++i) t[i].value.apply(that, args);
        }
    };

    function get(type, name) {
        for (var i = 0, n = type.length, c; i < n; ++i) {
            if ((c = type[i]).name === name) {
                return c.value;
            }
        }
    }

    function set(type, name, callback) {
        for (var i = 0, n = type.length; i < n; ++i) {
            if (type[i].name === name) {
                type[i] = noop, type = type.slice(0, i).concat(type.slice(i + 1));
                break;
            }
        }
        if (callback != null) type.push({name: name, value: callback});
        return type;
    }

    var xhtml = "http://www.w3.org/1999/xhtml";

    var namespaces = {
        svg: "http://www.w3.org/2000/svg",
        xhtml: xhtml,
        xlink: "http://www.w3.org/1999/xlink",
        xml: "http://www.w3.org/XML/1998/namespace",
        xmlns: "http://www.w3.org/2000/xmlns/"
    };

    function namespace(name) {
        var prefix = name += "", i = prefix.indexOf(":");
        if (i >= 0 && (prefix = name.slice(0, i)) !== "xmlns") name = name.slice(i + 1);
        return namespaces.hasOwnProperty(prefix) ? {space: namespaces[prefix], local: name} : name;
    }

    function creatorInherit(name) {
        return function() {
            var document = this.ownerDocument,
                uri = this.namespaceURI;
            return uri === xhtml && document.documentElement.namespaceURI === xhtml
                ? document.createElement(name)
                : document.createElementNS(uri, name);
        };
    }

    function creatorFixed(fullname) {
        return function() {
            return this.ownerDocument.createElementNS(fullname.space, fullname.local);
        };
    }

    function creator(name) {
        var fullname = namespace(name);
        return (fullname.local
            ? creatorFixed
            : creatorInherit)(fullname);
    }

    function none() {}

    function selector(selector) {
        return selector == null ? none : function() {
            return this.querySelector(selector);
        };
    }

    function selection_select(select) {
        if (typeof select !== "function") select = selector(select);

        for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
            for (var group = groups[j], n = group.length, subgroup = subgroups[j] = new Array(n), node, subnode, i = 0; i < n; ++i) {
                if ((node = group[i]) && (subnode = select.call(node, node.__data__, i, group))) {
                    if ("__data__" in node) subnode.__data__ = node.__data__;
                    subgroup[i] = subnode;
                }
            }
        }

        return new Selection(subgroups, this._parents);
    }

    function empty$1() {
        return [];
    }

    function selectorAll(selector) {
        return selector == null ? empty$1 : function() {
            return this.querySelectorAll(selector);
        };
    }

    function selection_selectAll(select) {
        if (typeof select !== "function") select = selectorAll(select);

        for (var groups = this._groups, m = groups.length, subgroups = [], parents = [], j = 0; j < m; ++j) {
            for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
                if (node = group[i]) {
                    subgroups.push(select.call(node, node.__data__, i, group));
                    parents.push(node);
                }
            }
        }

        return new Selection(subgroups, parents);
    }

    var matcher = function(selector) {
        return function() {
            return this.matches(selector);
        };
    };

    if (typeof document !== "undefined") {
        var element = document.documentElement;
        if (!element.matches) {
            var vendorMatches = element.webkitMatchesSelector
                || element.msMatchesSelector
                || element.mozMatchesSelector
                || element.oMatchesSelector;
            matcher = function(selector) {
                return function() {
                    return vendorMatches.call(this, selector);
                };
            };
        }
    }

    var matcher$1 = matcher;

    function selection_filter(match) {
        if (typeof match !== "function") match = matcher$1(match);

        for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
            for (var group = groups[j], n = group.length, subgroup = subgroups[j] = [], node, i = 0; i < n; ++i) {
                if ((node = group[i]) && match.call(node, node.__data__, i, group)) {
                    subgroup.push(node);
                }
            }
        }

        return new Selection(subgroups, this._parents);
    }

    function sparse(update) {
        return new Array(update.length);
    }

    function selection_enter() {
        return new Selection(this._enter || this._groups.map(sparse), this._parents);
    }

    function EnterNode(parent, datum) {
        this.ownerDocument = parent.ownerDocument;
        this.namespaceURI = parent.namespaceURI;
        this._next = null;
        this._parent = parent;
        this.__data__ = datum;
    }

    EnterNode.prototype = {
        constructor: EnterNode,
        appendChild: function(child) { return this._parent.insertBefore(child, this._next); },
        insertBefore: function(child, next) { return this._parent.insertBefore(child, next); },
        querySelector: function(selector) { return this._parent.querySelector(selector); },
        querySelectorAll: function(selector) { return this._parent.querySelectorAll(selector); }
    };

    function constant$1(x) {
        return function() {
            return x;
        };
    }

    var keyPrefix = "$"; // Protect against keys like “__proto__”.

    function bindIndex(parent, group, enter, update, exit, data) {
        var i = 0,
            node,
            groupLength = group.length,
            dataLength = data.length;

        // Put any non-null nodes that fit into update.
        // Put any null nodes into enter.
        // Put any remaining data into enter.
        for (; i < dataLength; ++i) {
            if (node = group[i]) {
                node.__data__ = data[i];
                update[i] = node;
            } else {
                enter[i] = new EnterNode(parent, data[i]);
            }
        }

        // Put any non-null nodes that don’t fit into exit.
        for (; i < groupLength; ++i) {
            if (node = group[i]) {
                exit[i] = node;
            }
        }
    }

    function bindKey(parent, group, enter, update, exit, data, key) {
        var i,
            node,
            nodeByKeyValue = {},
            groupLength = group.length,
            dataLength = data.length,
            keyValues = new Array(groupLength),
            keyValue;

        // Compute the key for each node.
        // If multiple nodes have the same key, the duplicates are added to exit.
        for (i = 0; i < groupLength; ++i) {
            if (node = group[i]) {
                keyValues[i] = keyValue = keyPrefix + key.call(node, node.__data__, i, group);
                if (keyValue in nodeByKeyValue) {
                    exit[i] = node;
                } else {
                    nodeByKeyValue[keyValue] = node;
                }
            }
        }

        // Compute the key for each datum.
        // If there a node associated with this key, join and add it to update.
        // If there is not (or the key is a duplicate), add it to enter.
        for (i = 0; i < dataLength; ++i) {
            keyValue = keyPrefix + key.call(parent, data[i], i, data);
            if (node = nodeByKeyValue[keyValue]) {
                update[i] = node;
                node.__data__ = data[i];
                nodeByKeyValue[keyValue] = null;
            } else {
                enter[i] = new EnterNode(parent, data[i]);
            }
        }

        // Add any remaining nodes that were not bound to data to exit.
        for (i = 0; i < groupLength; ++i) {
            if ((node = group[i]) && (nodeByKeyValue[keyValues[i]] === node)) {
                exit[i] = node;
            }
        }
    }

    function selection_data(value, key) {
        if (!value) {
            data = new Array(this.size()), j = -1;
            this.each(function(d) { data[++j] = d; });
            return data;
        }

        var bind = key ? bindKey : bindIndex,
            parents = this._parents,
            groups = this._groups;

        if (typeof value !== "function") value = constant$1(value);

        for (var m = groups.length, update = new Array(m), enter = new Array(m), exit = new Array(m), j = 0; j < m; ++j) {
            var parent = parents[j],
                group = groups[j],
                groupLength = group.length,
                data = value.call(parent, parent && parent.__data__, j, parents),
                dataLength = data.length,
                enterGroup = enter[j] = new Array(dataLength),
                updateGroup = update[j] = new Array(dataLength),
                exitGroup = exit[j] = new Array(groupLength);

            bind(parent, group, enterGroup, updateGroup, exitGroup, data, key);

            // Now connect the enter nodes to their following update node, such that
            // appendChild can insert the materialized enter node before this node,
            // rather than at the end of the parent node.
            for (var i0 = 0, i1 = 0, previous, next; i0 < dataLength; ++i0) {
                if (previous = enterGroup[i0]) {
                    if (i0 >= i1) i1 = i0 + 1;
                    while (!(next = updateGroup[i1]) && ++i1 < dataLength);
                    previous._next = next || null;
                }
            }
        }

        update = new Selection(update, parents);
        update._enter = enter;
        update._exit = exit;
        return update;
    }

    function selection_exit() {
        return new Selection(this._exit || this._groups.map(sparse), this._parents);
    }

    function selection_merge(selection$$1) {

        for (var groups0 = this._groups, groups1 = selection$$1._groups, m0 = groups0.length, m1 = groups1.length, m = Math.min(m0, m1), merges = new Array(m0), j = 0; j < m; ++j) {
            for (var group0 = groups0[j], group1 = groups1[j], n = group0.length, merge = merges[j] = new Array(n), node, i = 0; i < n; ++i) {
                if (node = group0[i] || group1[i]) {
                    merge[i] = node;
                }
            }
        }

        for (; j < m0; ++j) {
            merges[j] = groups0[j];
        }

        return new Selection(merges, this._parents);
    }

    function selection_order() {

        for (var groups = this._groups, j = -1, m = groups.length; ++j < m;) {
            for (var group = groups[j], i = group.length - 1, next = group[i], node; --i >= 0;) {
                if (node = group[i]) {
                    if (next && next !== node.nextSibling) next.parentNode.insertBefore(node, next);
                    next = node;
                }
            }
        }

        return this;
    }

    function selection_sort(compare) {
        if (!compare) compare = ascending$1;

        function compareNode(a, b) {
            return a && b ? compare(a.__data__, b.__data__) : !a - !b;
        }

        for (var groups = this._groups, m = groups.length, sortgroups = new Array(m), j = 0; j < m; ++j) {
            for (var group = groups[j], n = group.length, sortgroup = sortgroups[j] = new Array(n), node, i = 0; i < n; ++i) {
                if (node = group[i]) {
                    sortgroup[i] = node;
                }
            }
            sortgroup.sort(compareNode);
        }

        return new Selection(sortgroups, this._parents).order();
    }

    function ascending$1(a, b) {
        return a < b ? -1 : a > b ? 1 : a >= b ? 0 : NaN;
    }

    function selection_call() {
        var callback = arguments[0];
        arguments[0] = this;
        callback.apply(null, arguments);
        return this;
    }

    function selection_nodes() {
        var nodes = new Array(this.size()), i = -1;
        this.each(function() { nodes[++i] = this; });
        return nodes;
    }

    function selection_node() {

        for (var groups = this._groups, j = 0, m = groups.length; j < m; ++j) {
            for (var group = groups[j], i = 0, n = group.length; i < n; ++i) {
                var node = group[i];
                if (node) return node;
            }
        }

        return null;
    }

    function selection_size() {
        var size = 0;
        this.each(function() { ++size; });
        return size;
    }

    function selection_empty() {
        return !this.node();
    }

    function selection_each(callback) {

        for (var groups = this._groups, j = 0, m = groups.length; j < m; ++j) {
            for (var group = groups[j], i = 0, n = group.length, node; i < n; ++i) {
                if (node = group[i]) callback.call(node, node.__data__, i, group);
            }
        }

        return this;
    }

    function attrRemove(name) {
        return function() {
            this.removeAttribute(name);
        };
    }

    function attrRemoveNS(fullname) {
        return function() {
            this.removeAttributeNS(fullname.space, fullname.local);
        };
    }

    function attrConstant(name, value) {
        return function() {
            this.setAttribute(name, value);
        };
    }

    function attrConstantNS(fullname, value) {
        return function() {
            this.setAttributeNS(fullname.space, fullname.local, value);
        };
    }

    function attrFunction(name, value) {
        return function() {
            var v = value.apply(this, arguments);
            if (v == null) this.removeAttribute(name);
            else this.setAttribute(name, v);
        };
    }

    function attrFunctionNS(fullname, value) {
        return function() {
            var v = value.apply(this, arguments);
            if (v == null) this.removeAttributeNS(fullname.space, fullname.local);
            else this.setAttributeNS(fullname.space, fullname.local, v);
        };
    }

    function selection_attr(name, value) {
        var fullname = namespace(name);

        if (arguments.length < 2) {
            var node = this.node();
            return fullname.local
                ? node.getAttributeNS(fullname.space, fullname.local)
                : node.getAttribute(fullname);
        }

        return this.each((value == null
            ? (fullname.local ? attrRemoveNS : attrRemove) : (typeof value === "function"
                ? (fullname.local ? attrFunctionNS : attrFunction)
                : (fullname.local ? attrConstantNS : attrConstant)))(fullname, value));
    }

    function defaultView(node) {
        return (node.ownerDocument && node.ownerDocument.defaultView) // node is a Node
            || (node.document && node) // node is a Window
            || node.defaultView; // node is a Document
    }

    function styleRemove(name) {
        return function() {
            this.style.removeProperty(name);
        };
    }

    function styleConstant(name, value, priority) {
        return function() {
            this.style.setProperty(name, value, priority);
        };
    }

    function styleFunction(name, value, priority) {
        return function() {
            var v = value.apply(this, arguments);
            if (v == null) this.style.removeProperty(name);
            else this.style.setProperty(name, v, priority);
        };
    }

    function selection_style(name, value, priority) {
        return arguments.length > 1
            ? this.each((value == null
                ? styleRemove : typeof value === "function"
                    ? styleFunction
                    : styleConstant)(name, value, priority == null ? "" : priority))
            : styleValue(this.node(), name);
    }

    function styleValue(node, name) {
        return node.style.getPropertyValue(name)
            || defaultView(node).getComputedStyle(node, null).getPropertyValue(name);
    }

    function propertyRemove(name) {
        return function() {
            delete this[name];
        };
    }

    function propertyConstant(name, value) {
        return function() {
            this[name] = value;
        };
    }

    function propertyFunction(name, value) {
        return function() {
            var v = value.apply(this, arguments);
            if (v == null) delete this[name];
            else this[name] = v;
        };
    }

    function selection_property(name, value) {
        return arguments.length > 1
            ? this.each((value == null
                ? propertyRemove : typeof value === "function"
                    ? propertyFunction
                    : propertyConstant)(name, value))
            : this.node()[name];
    }

    function classArray(string) {
        return string.trim().split(/^|\s+/);
    }

    function classList(node) {
        return node.classList || new ClassList(node);
    }

    function ClassList(node) {
        this._node = node;
        this._names = classArray(node.getAttribute("class") || "");
    }

    ClassList.prototype = {
        add: function(name) {
            var i = this._names.indexOf(name);
            if (i < 0) {
                this._names.push(name);
                this._node.setAttribute("class", this._names.join(" "));
            }
        },
        remove: function(name) {
            var i = this._names.indexOf(name);
            if (i >= 0) {
                this._names.splice(i, 1);
                this._node.setAttribute("class", this._names.join(" "));
            }
        },
        contains: function(name) {
            return this._names.indexOf(name) >= 0;
        }
    };

    function classedAdd(node, names) {
        var list = classList(node), i = -1, n = names.length;
        while (++i < n) list.add(names[i]);
    }

    function classedRemove(node, names) {
        var list = classList(node), i = -1, n = names.length;
        while (++i < n) list.remove(names[i]);
    }

    function classedTrue(names) {
        return function() {
            classedAdd(this, names);
        };
    }

    function classedFalse(names) {
        return function() {
            classedRemove(this, names);
        };
    }

    function classedFunction(names, value) {
        return function() {
            (value.apply(this, arguments) ? classedAdd : classedRemove)(this, names);
        };
    }

    function selection_classed(name, value) {
        var names = classArray(name + "");

        if (arguments.length < 2) {
            var list = classList(this.node()), i = -1, n = names.length;
            while (++i < n) if (!list.contains(names[i])) return false;
            return true;
        }

        return this.each((typeof value === "function"
            ? classedFunction : value
                ? classedTrue
                : classedFalse)(names, value));
    }

    function textRemove() {
        this.textContent = "";
    }

    function textConstant(value) {
        return function() {
            this.textContent = value;
        };
    }

    function textFunction(value) {
        return function() {
            var v = value.apply(this, arguments);
            this.textContent = v == null ? "" : v;
        };
    }

    function selection_text(value) {
        return arguments.length
            ? this.each(value == null
                ? textRemove : (typeof value === "function"
                    ? textFunction
                    : textConstant)(value))
            : this.node().textContent;
    }

    function htmlRemove() {
        this.innerHTML = "";
    }

    function htmlConstant(value) {
        return function() {
            this.innerHTML = value;
        };
    }

    function htmlFunction(value) {
        return function() {
            var v = value.apply(this, arguments);
            this.innerHTML = v == null ? "" : v;
        };
    }

    function selection_html(value) {
        return arguments.length
            ? this.each(value == null
                ? htmlRemove : (typeof value === "function"
                    ? htmlFunction
                    : htmlConstant)(value))
            : this.node().innerHTML;
    }

    function raise() {
        if (this.nextSibling) this.parentNode.appendChild(this);
    }

    function selection_raise() {
        return this.each(raise);
    }

    function lower() {
        if (this.previousSibling) this.parentNode.insertBefore(this, this.parentNode.firstChild);
    }

    function selection_lower() {
        return this.each(lower);
    }

    function selection_append(name) {
        var create = typeof name === "function" ? name : creator(name);
        return this.select(function() {
            return this.appendChild(create.apply(this, arguments));
        });
    }

    function constantNull() {
        return null;
    }

    function selection_insert(name, before) {
        var create = typeof name === "function" ? name : creator(name),
            select = before == null ? constantNull : typeof before === "function" ? before : selector(before);
        return this.select(function() {
            return this.insertBefore(create.apply(this, arguments), select.apply(this, arguments) || null);
        });
    }

    function remove() {
        var parent = this.parentNode;
        if (parent) parent.removeChild(this);
    }

    function selection_remove() {
        return this.each(remove);
    }

    function selection_cloneShallow() {
        return this.parentNode.insertBefore(this.cloneNode(false), this.nextSibling);
    }

    function selection_cloneDeep() {
        return this.parentNode.insertBefore(this.cloneNode(true), this.nextSibling);
    }

    function selection_clone(deep) {
        return this.select(deep ? selection_cloneDeep : selection_cloneShallow);
    }

    function selection_datum(value) {
        return arguments.length
            ? this.property("__data__", value)
            : this.node().__data__;
    }

    var filterEvents = {};

    exports.event = null;

    if (typeof document !== "undefined") {
        var element$1 = document.documentElement;
        if (!("onmouseenter" in element$1)) {
            filterEvents = {mouseenter: "mouseover", mouseleave: "mouseout"};
        }
    }

    function filterContextListener(listener, index, group) {
        listener = contextListener(listener, index, group);
        return function(event) {
            var related = event.relatedTarget;
            if (!related || (related !== this && !(related.compareDocumentPosition(this) & 8))) {
                listener.call(this, event);
            }
        };
    }

    function contextListener(listener, index, group) {
        return function(event1) {
            var event0 = exports.event; // Events can be reentrant (e.g., focus).
            exports.event = event1;
            try {
                listener.call(this, this.__data__, index, group);
            } finally {
                exports.event = event0;
            }
        };
    }

    function parseTypenames$1(typenames) {
        return typenames.trim().split(/^|\s+/).map(function(t) {
            var name = "", i = t.indexOf(".");
            if (i >= 0) name = t.slice(i + 1), t = t.slice(0, i);
            return {type: t, name: name};
        });
    }

    function onRemove(typename) {
        return function() {
            var on = this.__on;
            if (!on) return;
            for (var j = 0, i = -1, m = on.length, o; j < m; ++j) {
                if (o = on[j], (!typename.type || o.type === typename.type) && o.name === typename.name) {
                    this.removeEventListener(o.type, o.listener, o.capture);
                } else {
                    on[++i] = o;
                }
            }
            if (++i) on.length = i;
            else delete this.__on;
        };
    }

    function onAdd(typename, value, capture) {
        var wrap = filterEvents.hasOwnProperty(typename.type) ? filterContextListener : contextListener;
        return function(d, i, group) {
            var on = this.__on, o, listener = wrap(value, i, group);
            if (on) for (var j = 0, m = on.length; j < m; ++j) {
                if ((o = on[j]).type === typename.type && o.name === typename.name) {
                    this.removeEventListener(o.type, o.listener, o.capture);
                    this.addEventListener(o.type, o.listener = listener, o.capture = capture);
                    o.value = value;
                    return;
                }
            }
            this.addEventListener(typename.type, listener, capture);
            o = {type: typename.type, name: typename.name, value: value, listener: listener, capture: capture};
            if (!on) this.__on = [o];
            else on.push(o);
        };
    }

    function selection_on(typename, value, capture) {
        var typenames = parseTypenames$1(typename + ""), i, n = typenames.length, t;

        if (arguments.length < 2) {
            var on = this.node().__on;
            if (on) for (var j = 0, m = on.length, o; j < m; ++j) {
                for (i = 0, o = on[j]; i < n; ++i) {
                    if ((t = typenames[i]).type === o.type && t.name === o.name) {
                        return o.value;
                    }
                }
            }
            return;
        }

        on = value ? onAdd : onRemove;
        if (capture == null) capture = false;
        for (i = 0; i < n; ++i) this.each(on(typenames[i], value, capture));
        return this;
    }

    function customEvent(event1, listener, that, args) {
        var event0 = exports.event;
        event1.sourceEvent = exports.event;
        exports.event = event1;
        try {
            return listener.apply(that, args);
        } finally {
            exports.event = event0;
        }
    }

    function dispatchEvent(node, type, params) {
        var window = defaultView(node),
            event = window.CustomEvent;

        if (typeof event === "function") {
            event = new event(type, params);
        } else {
            event = window.document.createEvent("Event");
            if (params) event.initEvent(type, params.bubbles, params.cancelable), event.detail = params.detail;
            else event.initEvent(type, false, false);
        }

        node.dispatchEvent(event);
    }

    function dispatchConstant(type, params) {
        return function() {
            return dispatchEvent(this, type, params);
        };
    }

    function dispatchFunction(type, params) {
        return function() {
            return dispatchEvent(this, type, params.apply(this, arguments));
        };
    }

    function selection_dispatch(type, params) {
        return this.each((typeof params === "function"
            ? dispatchFunction
            : dispatchConstant)(type, params));
    }

    var root = [null];

    function Selection(groups, parents) {
        this._groups = groups;
        this._parents = parents;
    }

    function selection() {
        return new Selection([[document.documentElement]], root);
    }

    Selection.prototype = selection.prototype = {
        constructor: Selection,
        select: selection_select,
        selectAll: selection_selectAll,
        filter: selection_filter,
        data: selection_data,
        enter: selection_enter,
        exit: selection_exit,
        merge: selection_merge,
        order: selection_order,
        sort: selection_sort,
        call: selection_call,
        nodes: selection_nodes,
        node: selection_node,
        size: selection_size,
        empty: selection_empty,
        each: selection_each,
        attr: selection_attr,
        style: selection_style,
        property: selection_property,
        classed: selection_classed,
        text: selection_text,
        html: selection_html,
        raise: selection_raise,
        lower: selection_lower,
        append: selection_append,
        insert: selection_insert,
        remove: selection_remove,
        clone: selection_clone,
        datum: selection_datum,
        on: selection_on,
        dispatch: selection_dispatch
    };

    function select(selector) {
        return typeof selector === "string"
            ? new Selection([[document.querySelector(selector)]], [document.documentElement])
            : new Selection([[selector]], root);
    }

    function create(name) {
        return select(creator(name).call(document.documentElement));
    }

    var nextId = 0;

    function local$1() {
        return new Local;
    }

    function Local() {
        this._ = "@" + (++nextId).toString(36);
    }

    Local.prototype = local$1.prototype = {
        constructor: Local,
        get: function(node) {
            var id = this._;
            while (!(id in node)) if (!(node = node.parentNode)) return;
            return node[id];
        },
        set: function(node, value) {
            return node[this._] = value;
        },
        remove: function(node) {
            return this._ in node && delete node[this._];
        },
        toString: function() {
            return this._;
        }
    };

    function sourceEvent() {
        var current = exports.event, source;
        while (source = current.sourceEvent) current = source;
        return current;
    }

    function point(node, event) {
        var svg = node.ownerSVGElement || node;

        if (svg.createSVGPoint) {
            var point = svg.createSVGPoint();
            point.x = event.clientX, point.y = event.clientY;
            point = point.matrixTransform(node.getScreenCTM().inverse());
            return [point.x, point.y];
        }

        var rect = node.getBoundingClientRect();
        return [event.clientX - rect.left - node.clientLeft, event.clientY - rect.top - node.clientTop];
    }

    function mouse(node) {
        var event = sourceEvent();
        if (event.changedTouches) event = event.changedTouches[0];
        return point(node, event);
    }

    function selectAll(selector) {
        return typeof selector === "string"
            ? new Selection([document.querySelectorAll(selector)], [document.documentElement])
            : new Selection([selector == null ? [] : selector], root);
    }

    function touch(node, touches, identifier) {
        if (arguments.length < 3) identifier = touches, touches = sourceEvent().changedTouches;

        for (var i = 0, n = touches ? touches.length : 0, touch; i < n; ++i) {
            if ((touch = touches[i]).identifier === identifier) {
                return point(node, touch);
            }
        }

        return null;
    }

    function touches(node, touches) {
        if (touches == null) touches = sourceEvent().touches;

        for (var i = 0, n = touches ? touches.length : 0, points = new Array(n); i < n; ++i) {
            points[i] = point(node, touches[i]);
        }

        return points;
    }

    function nopropagation() {
        exports.event.stopImmediatePropagation();
    }

    function noevent() {
        exports.event.preventDefault();
        exports.event.stopImmediatePropagation();
    }

    function dragDisable(view) {
        var root = view.document.documentElement,
            selection = select(view).on("dragstart.drag", noevent, true);
        if ("onselectstart" in root) {
            selection.on("selectstart.drag", noevent, true);
        } else {
            root.__noselect = root.style.MozUserSelect;
            root.style.MozUserSelect = "none";
        }
    }

    function yesdrag(view, noclick) {
        var root = view.document.documentElement,
            selection = select(view).on("dragstart.drag", null);
        if (noclick) {
            selection.on("click.drag", noevent, true);
            setTimeout(function() { selection.on("click.drag", null); }, 0);
        }
        if ("onselectstart" in root) {
            selection.on("selectstart.drag", null);
        } else {
            root.style.MozUserSelect = root.__noselect;
            delete root.__noselect;
        }
    }

    function constant$2(x) {
        return function() {
            return x;
        };
    }

    function DragEvent(target, type, subject, id, active, x, y, dx, dy, dispatch) {
        this.target = target;
        this.type = type;
        this.subject = subject;
        this.identifier = id;
        this.active = active;
        this.x = x;
        this.y = y;
        this.dx = dx;
        this.dy = dy;
        this._ = dispatch;
    }

    DragEvent.prototype.on = function() {
        var value = this._.on.apply(this._, arguments);
        return value === this._ ? this : value;
    };

// Ignore right-click, since that should open the context menu.
    function defaultFilter$1() {
        return !exports.event.button;
    }

    function defaultContainer() {
        return this.parentNode;
    }

    function defaultSubject(d) {
        return d == null ? {x: exports.event.x, y: exports.event.y} : d;
    }

    function defaultTouchable() {
        return "ontouchstart" in this;
    }

    function drag() {
        var filter = defaultFilter$1,
            container = defaultContainer,
            subject = defaultSubject,
            touchable = defaultTouchable,
            gestures = {},
            listeners = dispatch("start", "drag", "end"),
            active = 0,
            mousedownx,
            mousedowny,
            mousemoving,
            touchending,
            clickDistance2 = 0;

        function drag(selection) {
            selection
                .on("mousedown.drag", mousedowned)
                .filter(touchable)
                .on("touchstart.drag", touchstarted)
                .on("touchmove.drag", touchmoved)
                .on("touchend.drag touchcancel.drag", touchended)
                .style("touch-action", "none")
                .style("-webkit-tap-highlight-color", "rgba(0,0,0,0)");
        }

        function mousedowned() {
            if (touchending || !filter.apply(this, arguments)) return;
            var gesture = beforestart("mouse", container.apply(this, arguments), mouse, this, arguments);
            if (!gesture) return;
            select(exports.event.view).on("mousemove.drag", mousemoved, true).on("mouseup.drag", mouseupped, true);
            dragDisable(exports.event.view);
            nopropagation();
            mousemoving = false;
            mousedownx = exports.event.clientX;
            mousedowny = exports.event.clientY;
            gesture("start");
        }

        function mousemoved() {
            noevent();
            if (!mousemoving) {
                var dx = exports.event.clientX - mousedownx, dy = exports.event.clientY - mousedowny;
                mousemoving = dx * dx + dy * dy > clickDistance2;
            }
            gestures.mouse("drag");
        }

        function mouseupped() {
            select(exports.event.view).on("mousemove.drag mouseup.drag", null);
            yesdrag(exports.event.view, mousemoving);
            noevent();
            gestures.mouse("end");
        }

        function touchstarted() {
            if (!filter.apply(this, arguments)) return;
            var touches = exports.event.changedTouches,
                c = container.apply(this, arguments),
                n = touches.length, i, gesture;

            for (i = 0; i < n; ++i) {
                if (gesture = beforestart(touches[i].identifier, c, touch, this, arguments)) {
                    nopropagation();
                    gesture("start");
                }
            }
        }

        function touchmoved() {
            var touches = exports.event.changedTouches,
                n = touches.length, i, gesture;

            for (i = 0; i < n; ++i) {
                if (gesture = gestures[touches[i].identifier]) {
                    noevent();
                    gesture("drag");
                }
            }
        }

        function touchended() {
            var touches = exports.event.changedTouches,
                n = touches.length, i, gesture;

            if (touchending) clearTimeout(touchending);
            touchending = setTimeout(function() { touchending = null; }, 500); // Ghost clicks are delayed!
            for (i = 0; i < n; ++i) {
                if (gesture = gestures[touches[i].identifier]) {
                    nopropagation();
                    gesture("end");
                }
            }
        }

        function beforestart(id, container, point, that, args) {
            var p = point(container, id), s, dx, dy,
                sublisteners = listeners.copy();

            if (!customEvent(new DragEvent(drag, "beforestart", s, id, active, p[0], p[1], 0, 0, sublisteners), function() {
                if ((exports.event.subject = s = subject.apply(that, args)) == null) return false;
                dx = s.x - p[0] || 0;
                dy = s.y - p[1] || 0;
                return true;
            })) return;

            return function gesture(type) {
                var p0 = p, n;
                switch (type) {
                    case "start": gestures[id] = gesture, n = active++; break;
                    case "end": delete gestures[id], --active; // nobreak
                    case "drag": p = point(container, id), n = active; break;
                }
                customEvent(new DragEvent(drag, type, s, id, n, p[0] + dx, p[1] + dy, p[0] - p0[0], p[1] - p0[1], sublisteners), sublisteners.apply, sublisteners, [type, that, args]);
            };
        }

        drag.filter = function(_) {
            return arguments.length ? (filter = typeof _ === "function" ? _ : constant$2(!!_), drag) : filter;
        };

        drag.container = function(_) {
            return arguments.length ? (container = typeof _ === "function" ? _ : constant$2(_), drag) : container;
        };

        drag.subject = function(_) {
            return arguments.length ? (subject = typeof _ === "function" ? _ : constant$2(_), drag) : subject;
        };

        drag.touchable = function(_) {
            return arguments.length ? (touchable = typeof _ === "function" ? _ : constant$2(!!_), drag) : touchable;
        };

        drag.on = function() {
            var value = listeners.on.apply(listeners, arguments);
            return value === listeners ? drag : value;
        };

        drag.clickDistance = function(_) {
            return arguments.length ? (clickDistance2 = (_ = +_) * _, drag) : Math.sqrt(clickDistance2);
        };

        return drag;
    }

    function define(constructor, factory, prototype) {
        constructor.prototype = factory.prototype = prototype;
        prototype.constructor = constructor;
    }

    function extend(parent, definition) {
        var prototype = Object.create(parent.prototype);
        for (var key in definition) prototype[key] = definition[key];
        return prototype;
    }

    function Color() {}

    var darker = 0.7;
    var brighter = 1 / darker;

    var reI = "\\s*([+-]?\\d+)\\s*";
    var reN = "\\s*([+-]?\\d*\\.?\\d+(?:[eE][+-]?\\d+)?)\\s*";
    var reP = "\\s*([+-]?\\d*\\.?\\d+(?:[eE][+-]?\\d+)?)%\\s*";
    var reHex3 = /^#([0-9a-f]{3})$/;
    var reHex6 = /^#([0-9a-f]{6})$/;
    var reRgbInteger = new RegExp("^rgb\\(" + [reI, reI, reI] + "\\)$");
    var reRgbPercent = new RegExp("^rgb\\(" + [reP, reP, reP] + "\\)$");
    var reRgbaInteger = new RegExp("^rgba\\(" + [reI, reI, reI, reN] + "\\)$");
    var reRgbaPercent = new RegExp("^rgba\\(" + [reP, reP, reP, reN] + "\\)$");
    var reHslPercent = new RegExp("^hsl\\(" + [reN, reP, reP] + "\\)$");
    var reHslaPercent = new RegExp("^hsla\\(" + [reN, reP, reP, reN] + "\\)$");

    var named = {
        aliceblue: 0xf0f8ff,
        antiquewhite: 0xfaebd7,
        aqua: 0x00ffff,
        aquamarine: 0x7fffd4,
        azure: 0xf0ffff,
        beige: 0xf5f5dc,
        bisque: 0xffe4c4,
        black: 0x000000,
        blanchedalmond: 0xffebcd,
        blue: 0x0000ff,
        blueviolet: 0x8a2be2,
        brown: 0xa52a2a,
        burlywood: 0xdeb887,
        cadetblue: 0x5f9ea0,
        chartreuse: 0x7fff00,
        chocolate: 0xd2691e,
        coral: 0xff7f50,
        cornflowerblue: 0x6495ed,
        cornsilk: 0xfff8dc,
        crimson: 0xdc143c,
        cyan: 0x00ffff,
        darkblue: 0x00008b,
        darkcyan: 0x008b8b,
        darkgoldenrod: 0xb8860b,
        darkgray: 0xa9a9a9,
        darkgreen: 0x006400,
        darkgrey: 0xa9a9a9,
        darkkhaki: 0xbdb76b,
        darkmagenta: 0x8b008b,
        darkolivegreen: 0x556b2f,
        darkorange: 0xff8c00,
        darkorchid: 0x9932cc,
        darkred: 0x8b0000,
        darksalmon: 0xe9967a,
        darkseagreen: 0x8fbc8f,
        darkslateblue: 0x483d8b,
        darkslategray: 0x2f4f4f,
        darkslategrey: 0x2f4f4f,
        darkturquoise: 0x00ced1,
        darkviolet: 0x9400d3,
        deeppink: 0xff1493,
        deepskyblue: 0x00bfff,
        dimgray: 0x696969,
        dimgrey: 0x696969,
        dodgerblue: 0x1e90ff,
        firebrick: 0xb22222,
        floralwhite: 0xfffaf0,
        forestgreen: 0x228b22,
        fuchsia: 0xff00ff,
        gainsboro: 0xdcdcdc,
        ghostwhite: 0xf8f8ff,
        gold: 0xffd700,
        goldenrod: 0xdaa520,
        gray: 0x808080,
        green: 0x008000,
        greenyellow: 0xadff2f,
        grey: 0x808080,
        honeydew: 0xf0fff0,
        hotpink: 0xff69b4,
        indianred: 0xcd5c5c,
        indigo: 0x4b0082,
        ivory: 0xfffff0,
        khaki: 0xf0e68c,
        lavender: 0xe6e6fa,
        lavenderblush: 0xfff0f5,
        lawngreen: 0x7cfc00,
        lemonchiffon: 0xfffacd,
        lightblue: 0xadd8e6,
        lightcoral: 0xf08080,
        lightcyan: 0xe0ffff,
        lightgoldenrodyellow: 0xfafad2,
        lightgray: 0xd3d3d3,
        lightgreen: 0x90ee90,
        lightgrey: 0xd3d3d3,
        lightpink: 0xffb6c1,
        lightsalmon: 0xffa07a,
        lightseagreen: 0x20b2aa,
        lightskyblue: 0x87cefa,
        lightslategray: 0x778899,
        lightslategrey: 0x778899,
        lightsteelblue: 0xb0c4de,
        lightyellow: 0xffffe0,
        lime: 0x00ff00,
        limegreen: 0x32cd32,
        linen: 0xfaf0e6,
        magenta: 0xff00ff,
        maroon: 0x800000,
        mediumaquamarine: 0x66cdaa,
        mediumblue: 0x0000cd,
        mediumorchid: 0xba55d3,
        mediumpurple: 0x9370db,
        mediumseagreen: 0x3cb371,
        mediumslateblue: 0x7b68ee,
        mediumspringgreen: 0x00fa9a,
        mediumturquoise: 0x48d1cc,
        mediumvioletred: 0xc71585,
        midnightblue: 0x191970,
        mintcream: 0xf5fffa,
        mistyrose: 0xffe4e1,
        moccasin: 0xffe4b5,
        navajowhite: 0xffdead,
        navy: 0x000080,
        oldlace: 0xfdf5e6,
        olive: 0x808000,
        olivedrab: 0x6b8e23,
        orange: 0xffa500,
        orangered: 0xff4500,
        orchid: 0xda70d6,
        palegoldenrod: 0xeee8aa,
        palegreen: 0x98fb98,
        paleturquoise: 0xafeeee,
        palevioletred: 0xdb7093,
        papayawhip: 0xffefd5,
        peachpuff: 0xffdab9,
        peru: 0xcd853f,
        pink: 0xffc0cb,
        plum: 0xdda0dd,
        powderblue: 0xb0e0e6,
        purple: 0x800080,
        rebeccapurple: 0x663399,
        red: 0xff0000,
        rosybrown: 0xbc8f8f,
        royalblue: 0x4169e1,
        saddlebrown: 0x8b4513,
        salmon: 0xfa8072,
        sandybrown: 0xf4a460,
        seagreen: 0x2e8b57,
        seashell: 0xfff5ee,
        sienna: 0xa0522d,
        silver: 0xc0c0c0,
        skyblue: 0x87ceeb,
        slateblue: 0x6a5acd,
        slategray: 0x708090,
        slategrey: 0x708090,
        snow: 0xfffafa,
        springgreen: 0x00ff7f,
        steelblue: 0x4682b4,
        tan: 0xd2b48c,
        teal: 0x008080,
        thistle: 0xd8bfd8,
        tomato: 0xff6347,
        turquoise: 0x40e0d0,
        violet: 0xee82ee,
        wheat: 0xf5deb3,
        white: 0xffffff,
        whitesmoke: 0xf5f5f5,
        yellow: 0xffff00,
        yellowgreen: 0x9acd32
    };

    define(Color, color, {
        displayable: function() {
            return this.rgb().displayable();
        },
        toString: function() {
            return this.rgb() + "";
        }
    });

    function color(format) {
        var m;
        format = (format + "").trim().toLowerCase();
        return (m = reHex3.exec(format)) ? (m = parseInt(m[1], 16), new Rgb((m >> 8 & 0xf) | (m >> 4 & 0x0f0), (m >> 4 & 0xf) | (m & 0xf0), ((m & 0xf) << 4) | (m & 0xf), 1)) // #f00
            : (m = reHex6.exec(format)) ? rgbn(parseInt(m[1], 16)) // #ff0000
                : (m = reRgbInteger.exec(format)) ? new Rgb(m[1], m[2], m[3], 1) // rgb(255, 0, 0)
                    : (m = reRgbPercent.exec(format)) ? new Rgb(m[1] * 255 / 100, m[2] * 255 / 100, m[3] * 255 / 100, 1) // rgb(100%, 0%, 0%)
                        : (m = reRgbaInteger.exec(format)) ? rgba(m[1], m[2], m[3], m[4]) // rgba(255, 0, 0, 1)
                            : (m = reRgbaPercent.exec(format)) ? rgba(m[1] * 255 / 100, m[2] * 255 / 100, m[3] * 255 / 100, m[4]) // rgb(100%, 0%, 0%, 1)
                                : (m = reHslPercent.exec(format)) ? hsla(m[1], m[2] / 100, m[3] / 100, 1) // hsl(120, 50%, 50%)
                                    : (m = reHslaPercent.exec(format)) ? hsla(m[1], m[2] / 100, m[3] / 100, m[4]) // hsla(120, 50%, 50%, 1)
                                        : named.hasOwnProperty(format) ? rgbn(named[format])
                                            : format === "transparent" ? new Rgb(NaN, NaN, NaN, 0)
                                                : null;
    }

    function rgbn(n) {
        return new Rgb(n >> 16 & 0xff, n >> 8 & 0xff, n & 0xff, 1);
    }

    function rgba(r, g, b, a) {
        if (a <= 0) r = g = b = NaN;
        return new Rgb(r, g, b, a);
    }

    function rgbConvert(o) {
        if (!(o instanceof Color)) o = color(o);
        if (!o) return new Rgb;
        o = o.rgb();
        return new Rgb(o.r, o.g, o.b, o.opacity);
    }

    function rgb(r, g, b, opacity) {
        return arguments.length === 1 ? rgbConvert(r) : new Rgb(r, g, b, opacity == null ? 1 : opacity);
    }

    function Rgb(r, g, b, opacity) {
        this.r = +r;
        this.g = +g;
        this.b = +b;
        this.opacity = +opacity;
    }

    define(Rgb, rgb, extend(Color, {
        brighter: function(k) {
            k = k == null ? brighter : Math.pow(brighter, k);
            return new Rgb(this.r * k, this.g * k, this.b * k, this.opacity);
        },
        darker: function(k) {
            k = k == null ? darker : Math.pow(darker, k);
            return new Rgb(this.r * k, this.g * k, this.b * k, this.opacity);
        },
        rgb: function() {
            return this;
        },
        displayable: function() {
            return (0 <= this.r && this.r <= 255)
                && (0 <= this.g && this.g <= 255)
                && (0 <= this.b && this.b <= 255)
                && (0 <= this.opacity && this.opacity <= 1);
        },
        toString: function() {
            var a = this.opacity; a = isNaN(a) ? 1 : Math.max(0, Math.min(1, a));
            return (a === 1 ? "rgb(" : "rgba(")
                + Math.max(0, Math.min(255, Math.round(this.r) || 0)) + ", "
                + Math.max(0, Math.min(255, Math.round(this.g) || 0)) + ", "
                + Math.max(0, Math.min(255, Math.round(this.b) || 0))
                + (a === 1 ? ")" : ", " + a + ")");
        }
    }));

    function hsla(h, s, l, a) {
        if (a <= 0) h = s = l = NaN;
        else if (l <= 0 || l >= 1) h = s = NaN;
        else if (s <= 0) h = NaN;
        return new Hsl(h, s, l, a);
    }

    function hslConvert(o) {
        if (o instanceof Hsl) return new Hsl(o.h, o.s, o.l, o.opacity);
        if (!(o instanceof Color)) o = color(o);
        if (!o) return new Hsl;
        if (o instanceof Hsl) return o;
        o = o.rgb();
        var r = o.r / 255,
            g = o.g / 255,
            b = o.b / 255,
            min = Math.min(r, g, b),
            max = Math.max(r, g, b),
            h = NaN,
            s = max - min,
            l = (max + min) / 2;
        if (s) {
            if (r === max) h = (g - b) / s + (g < b) * 6;
            else if (g === max) h = (b - r) / s + 2;
            else h = (r - g) / s + 4;
            s /= l < 0.5 ? max + min : 2 - max - min;
            h *= 60;
        } else {
            s = l > 0 && l < 1 ? 0 : h;
        }
        return new Hsl(h, s, l, o.opacity);
    }

    function hsl(h, s, l, opacity) {
        return arguments.length === 1 ? hslConvert(h) : new Hsl(h, s, l, opacity == null ? 1 : opacity);
    }

    function Hsl(h, s, l, opacity) {
        this.h = +h;
        this.s = +s;
        this.l = +l;
        this.opacity = +opacity;
    }

    define(Hsl, hsl, extend(Color, {
        brighter: function(k) {
            k = k == null ? brighter : Math.pow(brighter, k);
            return new Hsl(this.h, this.s, this.l * k, this.opacity);
        },
        darker: function(k) {
            k = k == null ? darker : Math.pow(darker, k);
            return new Hsl(this.h, this.s, this.l * k, this.opacity);
        },
        rgb: function() {
            var h = this.h % 360 + (this.h < 0) * 360,
                s = isNaN(h) || isNaN(this.s) ? 0 : this.s,
                l = this.l,
                m2 = l + (l < 0.5 ? l : 1 - l) * s,
                m1 = 2 * l - m2;
            return new Rgb(
                hsl2rgb(h >= 240 ? h - 240 : h + 120, m1, m2),
                hsl2rgb(h, m1, m2),
                hsl2rgb(h < 120 ? h + 240 : h - 120, m1, m2),
                this.opacity
            );
        },
        displayable: function() {
            return (0 <= this.s && this.s <= 1 || isNaN(this.s))
                && (0 <= this.l && this.l <= 1)
                && (0 <= this.opacity && this.opacity <= 1);
        }
    }));

    /* From FvD 13.37, CSS Color Module Level 3 */
    function hsl2rgb(h, m1, m2) {
        return (h < 60 ? m1 + (m2 - m1) * h / 60
            : h < 180 ? m2
                : h < 240 ? m1 + (m2 - m1) * (240 - h) / 60
                    : m1) * 255;
    }

    var deg2rad = Math.PI / 180;
    var rad2deg = 180 / Math.PI;

    var Kn = 18;
    var Xn = 0.950470;
    var Yn = 1;
    var Zn = 1.088830;
    var t0 = 4 / 29;
    var t1 = 6 / 29;
    var t2 = 3 * t1 * t1;
    var t3 = t1 * t1 * t1;

    function labConvert(o) {
        if (o instanceof Lab) return new Lab(o.l, o.a, o.b, o.opacity);
        if (o instanceof Hcl) {
            var h = o.h * deg2rad;
            return new Lab(o.l, Math.cos(h) * o.c, Math.sin(h) * o.c, o.opacity);
        }
        if (!(o instanceof Rgb)) o = rgbConvert(o);
        var b = rgb2xyz(o.r),
            a = rgb2xyz(o.g),
            l = rgb2xyz(o.b),
            x = xyz2lab((0.4124564 * b + 0.3575761 * a + 0.1804375 * l) / Xn),
            y = xyz2lab((0.2126729 * b + 0.7151522 * a + 0.0721750 * l) / Yn),
            z = xyz2lab((0.0193339 * b + 0.1191920 * a + 0.9503041 * l) / Zn);
        return new Lab(116 * y - 16, 500 * (x - y), 200 * (y - z), o.opacity);
    }

    function lab(l, a, b, opacity) {
        return arguments.length === 1 ? labConvert(l) : new Lab(l, a, b, opacity == null ? 1 : opacity);
    }

    function Lab(l, a, b, opacity) {
        this.l = +l;
        this.a = +a;
        this.b = +b;
        this.opacity = +opacity;
    }

    define(Lab, lab, extend(Color, {
        brighter: function(k) {
            return new Lab(this.l + Kn * (k == null ? 1 : k), this.a, this.b, this.opacity);
        },
        darker: function(k) {
            return new Lab(this.l - Kn * (k == null ? 1 : k), this.a, this.b, this.opacity);
        },
        rgb: function() {
            var y = (this.l + 16) / 116,
                x = isNaN(this.a) ? y : y + this.a / 500,
                z = isNaN(this.b) ? y : y - this.b / 200;
            y = Yn * lab2xyz(y);
            x = Xn * lab2xyz(x);
            z = Zn * lab2xyz(z);
            return new Rgb(
                xyz2rgb( 3.2404542 * x - 1.5371385 * y - 0.4985314 * z), // D65 -> sRGB
                xyz2rgb(-0.9692660 * x + 1.8760108 * y + 0.0415560 * z),
                xyz2rgb( 0.0556434 * x - 0.2040259 * y + 1.0572252 * z),
                this.opacity
            );
        }
    }));

    function xyz2lab(t) {
        return t > t3 ? Math.pow(t, 1 / 3) : t / t2 + t0;
    }

    function lab2xyz(t) {
        return t > t1 ? t * t * t : t2 * (t - t0);
    }

    function xyz2rgb(x) {
        return 255 * (x <= 0.0031308 ? 12.92 * x : 1.055 * Math.pow(x, 1 / 2.4) - 0.055);
    }

    function rgb2xyz(x) {
        return (x /= 255) <= 0.04045 ? x / 12.92 : Math.pow((x + 0.055) / 1.055, 2.4);
    }

    function hclConvert(o) {
        if (o instanceof Hcl) return new Hcl(o.h, o.c, o.l, o.opacity);
        if (!(o instanceof Lab)) o = labConvert(o);
        var h = Math.atan2(o.b, o.a) * rad2deg;
        return new Hcl(h < 0 ? h + 360 : h, Math.sqrt(o.a * o.a + o.b * o.b), o.l, o.opacity);
    }

    function hcl(h, c, l, opacity) {
        return arguments.length === 1 ? hclConvert(h) : new Hcl(h, c, l, opacity == null ? 1 : opacity);
    }

    function Hcl(h, c, l, opacity) {
        this.h = +h;
        this.c = +c;
        this.l = +l;
        this.opacity = +opacity;
    }

    define(Hcl, hcl, extend(Color, {
        brighter: function(k) {
            return new Hcl(this.h, this.c, this.l + Kn * (k == null ? 1 : k), this.opacity);
        },
        darker: function(k) {
            return new Hcl(this.h, this.c, this.l - Kn * (k == null ? 1 : k), this.opacity);
        },
        rgb: function() {
            return labConvert(this).rgb();
        }
    }));

    var A = -0.14861;
    var B = +1.78277;
    var C = -0.29227;
    var D = -0.90649;
    var E = +1.97294;
    var ED = E * D;
    var EB = E * B;
    var BC_DA = B * C - D * A;

    function cubehelixConvert(o) {
        if (o instanceof Cubehelix) return new Cubehelix(o.h, o.s, o.l, o.opacity);
        if (!(o instanceof Rgb)) o = rgbConvert(o);
        var r = o.r / 255,
            g = o.g / 255,
            b = o.b / 255,
            l = (BC_DA * b + ED * r - EB * g) / (BC_DA + ED - EB),
            bl = b - l,
            k = (E * (g - l) - C * bl) / D,
            s = Math.sqrt(k * k + bl * bl) / (E * l * (1 - l)), // NaN if l=0 or l=1
            h = s ? Math.atan2(k, bl) * rad2deg - 120 : NaN;
        return new Cubehelix(h < 0 ? h + 360 : h, s, l, o.opacity);
    }

    function cubehelix(h, s, l, opacity) {
        return arguments.length === 1 ? cubehelixConvert(h) : new Cubehelix(h, s, l, opacity == null ? 1 : opacity);
    }

    function Cubehelix(h, s, l, opacity) {
        this.h = +h;
        this.s = +s;
        this.l = +l;
        this.opacity = +opacity;
    }

    define(Cubehelix, cubehelix, extend(Color, {
        brighter: function(k) {
            k = k == null ? brighter : Math.pow(brighter, k);
            return new Cubehelix(this.h, this.s, this.l * k, this.opacity);
        },
        darker: function(k) {
            k = k == null ? darker : Math.pow(darker, k);
            return new Cubehelix(this.h, this.s, this.l * k, this.opacity);
        },
        rgb: function() {
            var h = isNaN(this.h) ? 0 : (this.h + 120) * deg2rad,
                l = +this.l,
                a = isNaN(this.s) ? 0 : this.s * l * (1 - l),
                cosh = Math.cos(h),
                sinh = Math.sin(h);
            return new Rgb(
                255 * (l + a * (A * cosh + B * sinh)),
                255 * (l + a * (C * cosh + D * sinh)),
                255 * (l + a * (E * cosh)),
                this.opacity
            );
        }
    }));

    function basis(t1, v0, v1, v2, v3) {
        var t2 = t1 * t1, t3 = t2 * t1;
        return ((1 - 3 * t1 + 3 * t2 - t3) * v0
            + (4 - 6 * t2 + 3 * t3) * v1
            + (1 + 3 * t1 + 3 * t2 - 3 * t3) * v2
            + t3 * v3) / 6;
    }

    function basis$1(values) {
        var n = values.length - 1;
        return function(t) {
            var i = t <= 0 ? (t = 0) : t >= 1 ? (t = 1, n - 1) : Math.floor(t * n),
                v1 = values[i],
                v2 = values[i + 1],
                v0 = i > 0 ? values[i - 1] : 2 * v1 - v2,
                v3 = i < n - 1 ? values[i + 2] : 2 * v2 - v1;
            return basis((t - i / n) * n, v0, v1, v2, v3);
        };
    }

    function basisClosed(values) {
        var n = values.length;
        return function(t) {
            var i = Math.floor(((t %= 1) < 0 ? ++t : t) * n),
                v0 = values[(i + n - 1) % n],
                v1 = values[i % n],
                v2 = values[(i + 1) % n],
                v3 = values[(i + 2) % n];
            return basis((t - i / n) * n, v0, v1, v2, v3);
        };
    }

    function constant$3(x) {
        return function() {
            return x;
        };
    }

    function linear(a, d) {
        return function(t) {
            return a + t * d;
        };
    }

    function exponential(a, b, y) {
        return a = Math.pow(a, y), b = Math.pow(b, y) - a, y = 1 / y, function(t) {
            return Math.pow(a + t * b, y);
        };
    }

    function hue(a, b) {
        var d = b - a;
        return d ? linear(a, d > 180 || d < -180 ? d - 360 * Math.round(d / 360) : d) : constant$3(isNaN(a) ? b : a);
    }

    function gamma(y) {
        return (y = +y) === 1 ? nogamma : function(a, b) {
            return b - a ? exponential(a, b, y) : constant$3(isNaN(a) ? b : a);
        };
    }

    function nogamma(a, b) {
        var d = b - a;
        return d ? linear(a, d) : constant$3(isNaN(a) ? b : a);
    }

    var interpolateRgb = (function rgbGamma(y) {
        var color$$1 = gamma(y);

        function rgb$$1(start, end) {
            var r = color$$1((start = rgb(start)).r, (end = rgb(end)).r),
                g = color$$1(start.g, end.g),
                b = color$$1(start.b, end.b),
                opacity = nogamma(start.opacity, end.opacity);
            return function(t) {
                start.r = r(t);
                start.g = g(t);
                start.b = b(t);
                start.opacity = opacity(t);
                return start + "";
            };
        }

        rgb$$1.gamma = rgbGamma;

        return rgb$$1;
    })(1);

    function rgbSpline(spline) {
        return function(colors) {
            var n = colors.length,
                r = new Array(n),
                g = new Array(n),
                b = new Array(n),
                i, color$$1;
            for (i = 0; i < n; ++i) {
                color$$1 = rgb(colors[i]);
                r[i] = color$$1.r || 0;
                g[i] = color$$1.g || 0;
                b[i] = color$$1.b || 0;
            }
            r = spline(r);
            g = spline(g);
            b = spline(b);
            color$$1.opacity = 1;
            return function(t) {
                color$$1.r = r(t);
                color$$1.g = g(t);
                color$$1.b = b(t);
                return color$$1 + "";
            };
        };
    }

    var rgbBasis = rgbSpline(basis$1);
    var rgbBasisClosed = rgbSpline(basisClosed);

    function array$1(a, b) {
        var nb = b ? b.length : 0,
            na = a ? Math.min(nb, a.length) : 0,
            x = new Array(na),
            c = new Array(nb),
            i;

        for (i = 0; i < na; ++i) x[i] = interpolateValue(a[i], b[i]);
        for (; i < nb; ++i) c[i] = b[i];

        return function(t) {
            for (i = 0; i < na; ++i) c[i] = x[i](t);
            return c;
        };
    }

    function date(a, b) {
        var d = new Date;
        return a = +a, b -= a, function(t) {
            return d.setTime(a + b * t), d;
        };
    }

    function reinterpolate(a, b) {
        return a = +a, b -= a, function(t) {
            return a + b * t;
        };
    }

    function object(a, b) {
        var i = {},
            c = {},
            k;

        if (a === null || typeof a !== "object") a = {};
        if (b === null || typeof b !== "object") b = {};

        for (k in b) {
            if (k in a) {
                i[k] = interpolateValue(a[k], b[k]);
            } else {
                c[k] = b[k];
            }
        }

        return function(t) {
            for (k in i) c[k] = i[k](t);
            return c;
        };
    }

    var reA = /[-+]?(?:\d+\.?\d*|\.?\d+)(?:[eE][-+]?\d+)?/g;
    var reB = new RegExp(reA.source, "g");

    function zero(b) {
        return function() {
            return b;
        };
    }

    function one(b) {
        return function(t) {
            return b(t) + "";
        };
    }

    function interpolateString(a, b) {
        var bi = reA.lastIndex = reB.lastIndex = 0, // scan index for next number in b
            am, // current match in a
            bm, // current match in b
            bs, // string preceding current number in b, if any
            i = -1, // index in s
            s = [], // string constants and placeholders
            q = []; // number interpolators

        // Coerce inputs to strings.
        a = a + "", b = b + "";

        // Interpolate pairs of numbers in a & b.
        while ((am = reA.exec(a))
        && (bm = reB.exec(b))) {
            if ((bs = bm.index) > bi) { // a string precedes the next number in b
                bs = b.slice(bi, bs);
                if (s[i]) s[i] += bs; // coalesce with previous string
                else s[++i] = bs;
            }
            if ((am = am[0]) === (bm = bm[0])) { // numbers in a & b match
                if (s[i]) s[i] += bm; // coalesce with previous string
                else s[++i] = bm;
            } else { // interpolate non-matching numbers
                s[++i] = null;
                q.push({i: i, x: reinterpolate(am, bm)});
            }
            bi = reB.lastIndex;
        }

        // Add remains of b.
        if (bi < b.length) {
            bs = b.slice(bi);
            if (s[i]) s[i] += bs; // coalesce with previous string
            else s[++i] = bs;
        }

        // Special optimization for only a single match.
        // Otherwise, interpolate each of the numbers and rejoin the string.
        return s.length < 2 ? (q[0]
            ? one(q[0].x)
            : zero(b))
            : (b = q.length, function(t) {
                for (var i = 0, o; i < b; ++i) s[(o = q[i]).i] = o.x(t);
                return s.join("");
            });
    }

    function interpolateValue(a, b) {
        var t = typeof b, c;
        return b == null || t === "boolean" ? constant$3(b)
            : (t === "number" ? reinterpolate
                : t === "string" ? ((c = color(b)) ? (b = c, interpolateRgb) : interpolateString)
                    : b instanceof color ? interpolateRgb
                        : b instanceof Date ? date
                            : Array.isArray(b) ? array$1
                                : typeof b.valueOf !== "function" && typeof b.toString !== "function" || isNaN(b) ? object
                                    : reinterpolate)(a, b);
    }

    function interpolateRound(a, b) {
        return a = +a, b -= a, function(t) {
            return Math.round(a + b * t);
        };
    }

    var degrees = 180 / Math.PI;

    var identity$2 = {
        translateX: 0,
        translateY: 0,
        rotate: 0,
        skewX: 0,
        scaleX: 1,
        scaleY: 1
    };

    function decompose(a, b, c, d, e, f) {
        var scaleX, scaleY, skewX;
        if (scaleX = Math.sqrt(a * a + b * b)) a /= scaleX, b /= scaleX;
        if (skewX = a * c + b * d) c -= a * skewX, d -= b * skewX;
        if (scaleY = Math.sqrt(c * c + d * d)) c /= scaleY, d /= scaleY, skewX /= scaleY;
        if (a * d < b * c) a = -a, b = -b, skewX = -skewX, scaleX = -scaleX;
        return {
            translateX: e,
            translateY: f,
            rotate: Math.atan2(b, a) * degrees,
            skewX: Math.atan(skewX) * degrees,
            scaleX: scaleX,
            scaleY: scaleY
        };
    }

    var cssNode;
    var cssRoot;
    var cssView;
    var svgNode;

    function parseCss(value) {
        if (value === "none") return identity$2;
        if (!cssNode) cssNode = document.createElement("DIV"), cssRoot = document.documentElement, cssView = document.defaultView;
        cssNode.style.transform = value;
        value = cssView.getComputedStyle(cssRoot.appendChild(cssNode), null).getPropertyValue("transform");
        cssRoot.removeChild(cssNode);
        value = value.slice(7, -1).split(",");
        return decompose(+value[0], +value[1], +value[2], +value[3], +value[4], +value[5]);
    }

    function parseSvg(value) {
        if (value == null) return identity$2;
        if (!svgNode) svgNode = document.createElementNS("http://www.w3.org/2000/svg", "g");
        svgNode.setAttribute("transform", value);
        if (!(value = svgNode.transform.baseVal.consolidate())) return identity$2;
        value = value.matrix;
        return decompose(value.a, value.b, value.c, value.d, value.e, value.f);
    }

    function interpolateTransform(parse, pxComma, pxParen, degParen) {

        function pop(s) {
            return s.length ? s.pop() + " " : "";
        }

        function translate(xa, ya, xb, yb, s, q) {
            if (xa !== xb || ya !== yb) {
                var i = s.push("translate(", null, pxComma, null, pxParen);
                q.push({i: i - 4, x: reinterpolate(xa, xb)}, {i: i - 2, x: reinterpolate(ya, yb)});
            } else if (xb || yb) {
                s.push("translate(" + xb + pxComma + yb + pxParen);
            }
        }

        function rotate(a, b, s, q) {
            if (a !== b) {
                if (a - b > 180) b += 360; else if (b - a > 180) a += 360; // shortest path
                q.push({i: s.push(pop(s) + "rotate(", null, degParen) - 2, x: reinterpolate(a, b)});
            } else if (b) {
                s.push(pop(s) + "rotate(" + b + degParen);
            }
        }

        function skewX(a, b, s, q) {
            if (a !== b) {
                q.push({i: s.push(pop(s) + "skewX(", null, degParen) - 2, x: reinterpolate(a, b)});
            } else if (b) {
                s.push(pop(s) + "skewX(" + b + degParen);
            }
        }

        function scale(xa, ya, xb, yb, s, q) {
            if (xa !== xb || ya !== yb) {
                var i = s.push(pop(s) + "scale(", null, ",", null, ")");
                q.push({i: i - 4, x: reinterpolate(xa, xb)}, {i: i - 2, x: reinterpolate(ya, yb)});
            } else if (xb !== 1 || yb !== 1) {
                s.push(pop(s) + "scale(" + xb + "," + yb + ")");
            }
        }

        return function(a, b) {
            var s = [], // string constants and placeholders
                q = []; // number interpolators
            a = parse(a), b = parse(b);
            translate(a.translateX, a.translateY, b.translateX, b.translateY, s, q);
            rotate(a.rotate, b.rotate, s, q);
            skewX(a.skewX, b.skewX, s, q);
            scale(a.scaleX, a.scaleY, b.scaleX, b.scaleY, s, q);
            a = b = null; // gc
            return function(t) {
                var i = -1, n = q.length, o;
                while (++i < n) s[(o = q[i]).i] = o.x(t);
                return s.join("");
            };
        };
    }

    var interpolateTransformCss = interpolateTransform(parseCss, "px, ", "px)", "deg)");
    var interpolateTransformSvg = interpolateTransform(parseSvg, ", ", ")", ")");

    var rho = Math.SQRT2;
    var rho2 = 2;
    var rho4 = 4;
    var epsilon2 = 1e-12;

    function cosh(x) {
        return ((x = Math.exp(x)) + 1 / x) / 2;
    }

    function sinh(x) {
        return ((x = Math.exp(x)) - 1 / x) / 2;
    }

    function tanh(x) {
        return ((x = Math.exp(2 * x)) - 1) / (x + 1);
    }

// p0 = [ux0, uy0, w0]
// p1 = [ux1, uy1, w1]
    function interpolateZoom(p0, p1) {
        var ux0 = p0[0], uy0 = p0[1], w0 = p0[2],
            ux1 = p1[0], uy1 = p1[1], w1 = p1[2],
            dx = ux1 - ux0,
            dy = uy1 - uy0,
            d2 = dx * dx + dy * dy,
            i,
            S;

        // Special case for u0 ≅ u1.
        if (d2 < epsilon2) {
            S = Math.log(w1 / w0) / rho;
            i = function(t) {
                return [
                    ux0 + t * dx,
                    uy0 + t * dy,
                    w0 * Math.exp(rho * t * S)
                ];
            };
        }

        // General case.
        else {
            var d1 = Math.sqrt(d2),
                b0 = (w1 * w1 - w0 * w0 + rho4 * d2) / (2 * w0 * rho2 * d1),
                b1 = (w1 * w1 - w0 * w0 - rho4 * d2) / (2 * w1 * rho2 * d1),
                r0 = Math.log(Math.sqrt(b0 * b0 + 1) - b0),
                r1 = Math.log(Math.sqrt(b1 * b1 + 1) - b1);
            S = (r1 - r0) / rho;
            i = function(t) {
                var s = t * S,
                    coshr0 = cosh(r0),
                    u = w0 / (rho2 * d1) * (coshr0 * tanh(rho * s + r0) - sinh(r0));
                return [
                    ux0 + u * dx,
                    uy0 + u * dy,
                    w0 * coshr0 / cosh(rho * s + r0)
                ];
            };
        }

        i.duration = S * 1000;

        return i;
    }

    function hsl$1(hue$$1) {
        return function(start, end) {
            var h = hue$$1((start = hsl(start)).h, (end = hsl(end)).h),
                s = nogamma(start.s, end.s),
                l = nogamma(start.l, end.l),
                opacity = nogamma(start.opacity, end.opacity);
            return function(t) {
                start.h = h(t);
                start.s = s(t);
                start.l = l(t);
                start.opacity = opacity(t);
                return start + "";
            };
        }
    }

    var hsl$2 = hsl$1(hue);
    var hslLong = hsl$1(nogamma);

    function lab$1(start, end) {
        var l = nogamma((start = lab(start)).l, (end = lab(end)).l),
            a = nogamma(start.a, end.a),
            b = nogamma(start.b, end.b),
            opacity = nogamma(start.opacity, end.opacity);
        return function(t) {
            start.l = l(t);
            start.a = a(t);
            start.b = b(t);
            start.opacity = opacity(t);
            return start + "";
        };
    }

    function hcl$1(hue$$1) {
        return function(start, end) {
            var h = hue$$1((start = hcl(start)).h, (end = hcl(end)).h),
                c = nogamma(start.c, end.c),
                l = nogamma(start.l, end.l),
                opacity = nogamma(start.opacity, end.opacity);
            return function(t) {
                start.h = h(t);
                start.c = c(t);
                start.l = l(t);
                start.opacity = opacity(t);
                return start + "";
            };
        }
    }

    var hcl$2 = hcl$1(hue);
    var hclLong = hcl$1(nogamma);

    function cubehelix$1(hue$$1) {
        return (function cubehelixGamma(y) {
            y = +y;

            function cubehelix$$1(start, end) {
                var h = hue$$1((start = cubehelix(start)).h, (end = cubehelix(end)).h),
                    s = nogamma(start.s, end.s),
                    l = nogamma(start.l, end.l),
                    opacity = nogamma(start.opacity, end.opacity);
                return function(t) {
                    start.h = h(t);
                    start.s = s(t);
                    start.l = l(Math.pow(t, y));
                    start.opacity = opacity(t);
                    return start + "";
                };
            }

            cubehelix$$1.gamma = cubehelixGamma;

            return cubehelix$$1;
        })(1);
    }

    var cubehelix$2 = cubehelix$1(hue);
    var cubehelixLong = cubehelix$1(nogamma);

    function quantize(interpolator, n) {
        var samples = new Array(n);
        for (var i = 0; i < n; ++i) samples[i] = interpolator(i / (n - 1));
        return samples;
    }

    var frame = 0;
    var timeout = 0;
    var interval = 0;
    var pokeDelay = 1000;
    var taskHead;
    var taskTail;
    var clockLast = 0;
    var clockNow = 0;
    var clockSkew = 0;
    var clock = typeof performance === "object" && performance.now ? performance : Date;
    var setFrame = typeof window === "object" && window.requestAnimationFrame ? window.requestAnimationFrame.bind(window) : function(f) { setTimeout(f, 17); };

    function now() {
        return clockNow || (setFrame(clearNow), clockNow = clock.now() + clockSkew);
    }

    function clearNow() {
        clockNow = 0;
    }

    function Timer() {
        this._call =
            this._time =
                this._next = null;
    }

    Timer.prototype = timer.prototype = {
        constructor: Timer,
        restart: function(callback, delay, time) {
            if (typeof callback !== "function") throw new TypeError("callback is not a function");
            time = (time == null ? now() : +time) + (delay == null ? 0 : +delay);
            if (!this._next && taskTail !== this) {
                if (taskTail) taskTail._next = this;
                else taskHead = this;
                taskTail = this;
            }
            this._call = callback;
            this._time = time;
            sleep();
        },
        stop: function() {
            if (this._call) {
                this._call = null;
                this._time = Infinity;
                sleep();
            }
        }
    };

    function timer(callback, delay, time) {
        var t = new Timer;
        t.restart(callback, delay, time);
        return t;
    }

    function timerFlush() {
        now(); // Get the current time, if not already set.
        ++frame; // Pretend we’ve set an alarm, if we haven’t already.
        var t = taskHead, e;
        while (t) {
            if ((e = clockNow - t._time) >= 0) t._call.call(null, e);
            t = t._next;
        }
        --frame;
    }

    function wake() {
        clockNow = (clockLast = clock.now()) + clockSkew;
        frame = timeout = 0;
        try {
            timerFlush();
        } finally {
            frame = 0;
            nap();
            clockNow = 0;
        }
    }

    function poke() {
        var now = clock.now(), delay = now - clockLast;
        if (delay > pokeDelay) clockSkew -= delay, clockLast = now;
    }

    function nap() {
        var t0, t1 = taskHead, t2, time = Infinity;
        while (t1) {
            if (t1._call) {
                if (time > t1._time) time = t1._time;
                t0 = t1, t1 = t1._next;
            } else {
                t2 = t1._next, t1._next = null;
                t1 = t0 ? t0._next = t2 : taskHead = t2;
            }
        }
        taskTail = t0;
        sleep(time);
    }

    function sleep(time) {
        if (frame) return; // Soonest alarm already set, or will be.
        if (timeout) timeout = clearTimeout(timeout);
        var delay = time - clockNow; // Strictly less than if we recomputed clockNow.
        if (delay > 24) {
            if (time < Infinity) timeout = setTimeout(wake, time - clock.now() - clockSkew);
            if (interval) interval = clearInterval(interval);
        } else {
            if (!interval) clockLast = clock.now(), interval = setInterval(poke, pokeDelay);
            frame = 1, setFrame(wake);
        }
    }

    function timeout$1(callback, delay, time) {
        var t = new Timer;
        delay = delay == null ? 0 : +delay;
        t.restart(function(elapsed) {
            t.stop();
            callback(elapsed + delay);
        }, delay, time);
        return t;
    }

    function interval$1(callback, delay, time) {
        var t = new Timer, total = delay;
        if (delay == null) return t.restart(callback, delay, time), t;
        delay = +delay, time = time == null ? now() : +time;
        t.restart(function tick(elapsed) {
            elapsed += total;
            t.restart(tick, total += delay, time);
            callback(elapsed);
        }, delay, time);
        return t;
    }

    var emptyOn = dispatch("start", "end", "interrupt");
    var emptyTween = [];

    var CREATED = 0;
    var SCHEDULED = 1;
    var STARTING = 2;
    var STARTED = 3;
    var RUNNING = 4;
    var ENDING = 5;
    var ENDED = 6;

    function schedule(node, name, id, index, group, timing) {
        var schedules = node.__transition;
        if (!schedules) node.__transition = {};
        else if (id in schedules) return;
        create$1(node, id, {
            name: name,
            index: index, // For context during callback.
            group: group, // For context during callback.
            on: emptyOn,
            tween: emptyTween,
            time: timing.time,
            delay: timing.delay,
            duration: timing.duration,
            ease: timing.ease,
            timer: null,
            state: CREATED
        });
    }

    function init(node, id) {
        var schedule = get$1(node, id);
        if (schedule.state > CREATED) throw new Error("too late; already scheduled");
        return schedule;
    }

    function set$1(node, id) {
        var schedule = get$1(node, id);
        if (schedule.state > STARTING) throw new Error("too late; already started");
        return schedule;
    }

    function get$1(node, id) {
        var schedule = node.__transition;
        if (!schedule || !(schedule = schedule[id])) throw new Error("transition not found");
        return schedule;
    }

    function create$1(node, id, self) {
        var schedules = node.__transition,
            tween;

        // Initialize the self timer when the transition is created.
        // Note the actual delay is not known until the first callback!
        schedules[id] = self;
        self.timer = timer(schedule, 0, self.time);

        function schedule(elapsed) {
            self.state = SCHEDULED;
            self.timer.restart(start, self.delay, self.time);

            // If the elapsed delay is less than our first sleep, start immediately.
            if (self.delay <= elapsed) start(elapsed - self.delay);
        }

        function start(elapsed) {
            var i, j, n, o;

            // If the state is not SCHEDULED, then we previously errored on start.
            if (self.state !== SCHEDULED) return stop();

            for (i in schedules) {
                o = schedules[i];
                if (o.name !== self.name) continue;

                // While this element already has a starting transition during this frame,
                // defer starting an interrupting transition until that transition has a
                // chance to tick (and possibly end); see d3/d3-transition#54!
                if (o.state === STARTED) return timeout$1(start);

                // Interrupt the active transition, if any.
                // Dispatch the interrupt event.
                if (o.state === RUNNING) {
                    o.state = ENDED;
                    o.timer.stop();
                    o.on.call("interrupt", node, node.__data__, o.index, o.group);
                    delete schedules[i];
                }

                    // Cancel any pre-empted transitions. No interrupt event is dispatched
                    // because the cancelled transitions never started. Note that this also
                // removes this transition from the pending list!
                else if (+i < id) {
                    o.state = ENDED;
                    o.timer.stop();
                    delete schedules[i];
                }
            }

            // Defer the first tick to end of the current frame; see d3/d3#1576.
            // Note the transition may be canceled after start and before the first tick!
            // Note this must be scheduled before the start event; see d3/d3-transition#16!
            // Assuming this is successful, subsequent callbacks go straight to tick.
            timeout$1(function() {
                if (self.state === STARTED) {
                    self.state = RUNNING;
                    self.timer.restart(tick, self.delay, self.time);
                    tick(elapsed);
                }
            });

            // Dispatch the start event.
            // Note this must be done before the tween are initialized.
            self.state = STARTING;
            self.on.call("start", node, node.__data__, self.index, self.group);
            if (self.state !== STARTING) return; // interrupted
            self.state = STARTED;

            // Initialize the tween, deleting null tween.
            tween = new Array(n = self.tween.length);
            for (i = 0, j = -1; i < n; ++i) {
                if (o = self.tween[i].value.call(node, node.__data__, self.index, self.group)) {
                    tween[++j] = o;
                }
            }
            tween.length = j + 1;
        }

        function tick(elapsed) {
            var t = elapsed < self.duration ? self.ease.call(null, elapsed / self.duration) : (self.timer.restart(stop), self.state = ENDING, 1),
                i = -1,
                n = tween.length;

            while (++i < n) {
                tween[i].call(null, t);
            }

            // Dispatch the end event.
            if (self.state === ENDING) {
                self.on.call("end", node, node.__data__, self.index, self.group);
                stop();
            }
        }

        function stop() {
            self.state = ENDED;
            self.timer.stop();
            delete schedules[id];
            for (var i in schedules) return; // eslint-disable-line no-unused-vars
            delete node.__transition;
        }
    }

    function interrupt(node, name) {
        var schedules = node.__transition,
            schedule$$1,
            active,
            empty = true,
            i;

        if (!schedules) return;

        name = name == null ? null : name + "";

        for (i in schedules) {
            if ((schedule$$1 = schedules[i]).name !== name) { empty = false; continue; }
            active = schedule$$1.state > STARTING && schedule$$1.state < ENDING;
            schedule$$1.state = ENDED;
            schedule$$1.timer.stop();
            if (active) schedule$$1.on.call("interrupt", node, node.__data__, schedule$$1.index, schedule$$1.group);
            delete schedules[i];
        }

        if (empty) delete node.__transition;
    }

    function selection_interrupt(name) {
        return this.each(function() {
            interrupt(this, name);
        });
    }

    function tweenRemove(id, name) {
        var tween0, tween1;
        return function() {
            var schedule$$1 = set$1(this, id),
                tween = schedule$$1.tween;

            // If this node shared tween with the previous node,
            // just assign the updated shared tween and we’re done!
            // Otherwise, copy-on-write.
            if (tween !== tween0) {
                tween1 = tween0 = tween;
                for (var i = 0, n = tween1.length; i < n; ++i) {
                    if (tween1[i].name === name) {
                        tween1 = tween1.slice();
                        tween1.splice(i, 1);
                        break;
                    }
                }
            }

            schedule$$1.tween = tween1;
        };
    }

    function tweenFunction(id, name, value) {
        var tween0, tween1;
        if (typeof value !== "function") throw new Error;
        return function() {
            var schedule$$1 = set$1(this, id),
                tween = schedule$$1.tween;

            // If this node shared tween with the previous node,
            // just assign the updated shared tween and we’re done!
            // Otherwise, copy-on-write.
            if (tween !== tween0) {
                tween1 = (tween0 = tween).slice();
                for (var t = {name: name, value: value}, i = 0, n = tween1.length; i < n; ++i) {
                    if (tween1[i].name === name) {
                        tween1[i] = t;
                        break;
                    }
                }
                if (i === n) tween1.push(t);
            }

            schedule$$1.tween = tween1;
        };
    }

    function transition_tween(name, value) {
        var id = this._id;

        name += "";

        if (arguments.length < 2) {
            var tween = get$1(this.node(), id).tween;
            for (var i = 0, n = tween.length, t; i < n; ++i) {
                if ((t = tween[i]).name === name) {
                    return t.value;
                }
            }
            return null;
        }

        return this.each((value == null ? tweenRemove : tweenFunction)(id, name, value));
    }

    function tweenValue(transition, name, value) {
        var id = transition._id;

        transition.each(function() {
            var schedule$$1 = set$1(this, id);
            (schedule$$1.value || (schedule$$1.value = {}))[name] = value.apply(this, arguments);
        });

        return function(node) {
            return get$1(node, id).value[name];
        };
    }

    function interpolate(a, b) {
        var c;
        return (typeof b === "number" ? reinterpolate
            : b instanceof color ? interpolateRgb
                : (c = color(b)) ? (b = c, interpolateRgb)
                    : interpolateString)(a, b);
    }

    function attrRemove$1(name) {
        return function() {
            this.removeAttribute(name);
        };
    }

    function attrRemoveNS$1(fullname) {
        return function() {
            this.removeAttributeNS(fullname.space, fullname.local);
        };
    }

    function attrConstant$1(name, interpolate$$1, value1) {
        var value00,
            interpolate0;
        return function() {
            var value0 = this.getAttribute(name);
            return value0 === value1 ? null
                : value0 === value00 ? interpolate0
                    : interpolate0 = interpolate$$1(value00 = value0, value1);
        };
    }

    function attrConstantNS$1(fullname, interpolate$$1, value1) {
        var value00,
            interpolate0;
        return function() {
            var value0 = this.getAttributeNS(fullname.space, fullname.local);
            return value0 === value1 ? null
                : value0 === value00 ? interpolate0
                    : interpolate0 = interpolate$$1(value00 = value0, value1);
        };
    }

    function attrFunction$1(name, interpolate$$1, value) {
        var value00,
            value10,
            interpolate0;
        return function() {
            var value0, value1 = value(this);
            if (value1 == null) return void this.removeAttribute(name);
            value0 = this.getAttribute(name);
            return value0 === value1 ? null
                : value0 === value00 && value1 === value10 ? interpolate0
                    : interpolate0 = interpolate$$1(value00 = value0, value10 = value1);
        };
    }

    function attrFunctionNS$1(fullname, interpolate$$1, value) {
        var value00,
            value10,
            interpolate0;
        return function() {
            var value0, value1 = value(this);
            if (value1 == null) return void this.removeAttributeNS(fullname.space, fullname.local);
            value0 = this.getAttributeNS(fullname.space, fullname.local);
            return value0 === value1 ? null
                : value0 === value00 && value1 === value10 ? interpolate0
                    : interpolate0 = interpolate$$1(value00 = value0, value10 = value1);
        };
    }

    function transition_attr(name, value) {
        var fullname = namespace(name), i = fullname === "transform" ? interpolateTransformSvg : interpolate;
        return this.attrTween(name, typeof value === "function"
            ? (fullname.local ? attrFunctionNS$1 : attrFunction$1)(fullname, i, tweenValue(this, "attr." + name, value))
            : value == null ? (fullname.local ? attrRemoveNS$1 : attrRemove$1)(fullname)
                : (fullname.local ? attrConstantNS$1 : attrConstant$1)(fullname, i, value + ""));
    }

    function attrTweenNS(fullname, value) {
        function tween() {
            var node = this, i = value.apply(node, arguments);
            return i && function(t) {
                node.setAttributeNS(fullname.space, fullname.local, i(t));
            };
        }
        tween._value = value;
        return tween;
    }

    function attrTween(name, value) {
        function tween() {
            var node = this, i = value.apply(node, arguments);
            return i && function(t) {
                node.setAttribute(name, i(t));
            };
        }
        tween._value = value;
        return tween;
    }

    function transition_attrTween(name, value) {
        var key = "attr." + name;
        if (arguments.length < 2) return (key = this.tween(key)) && key._value;
        if (value == null) return this.tween(key, null);
        if (typeof value !== "function") throw new Error;
        var fullname = namespace(name);
        return this.tween(key, (fullname.local ? attrTweenNS : attrTween)(fullname, value));
    }

    function delayFunction(id, value) {
        return function() {
            init(this, id).delay = +value.apply(this, arguments);
        };
    }

    function delayConstant(id, value) {
        return value = +value, function() {
            init(this, id).delay = value;
        };
    }

    function transition_delay(value) {
        var id = this._id;

        return arguments.length
            ? this.each((typeof value === "function"
                ? delayFunction
                : delayConstant)(id, value))
            : get$1(this.node(), id).delay;
    }

    function durationFunction(id, value) {
        return function() {
            set$1(this, id).duration = +value.apply(this, arguments);
        };
    }

    function durationConstant(id, value) {
        return value = +value, function() {
            set$1(this, id).duration = value;
        };
    }

    function transition_duration(value) {
        var id = this._id;

        return arguments.length
            ? this.each((typeof value === "function"
                ? durationFunction
                : durationConstant)(id, value))
            : get$1(this.node(), id).duration;
    }

    function easeConstant(id, value) {
        if (typeof value !== "function") throw new Error;
        return function() {
            set$1(this, id).ease = value;
        };
    }

    function transition_ease(value) {
        var id = this._id;

        return arguments.length
            ? this.each(easeConstant(id, value))
            : get$1(this.node(), id).ease;
    }

    function transition_filter(match) {
        if (typeof match !== "function") match = matcher$1(match);

        for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
            for (var group = groups[j], n = group.length, subgroup = subgroups[j] = [], node, i = 0; i < n; ++i) {
                if ((node = group[i]) && match.call(node, node.__data__, i, group)) {
                    subgroup.push(node);
                }
            }
        }

        return new Transition(subgroups, this._parents, this._name, this._id);
    }

    function transition_merge(transition$$1) {
        if (transition$$1._id !== this._id) throw new Error;

        for (var groups0 = this._groups, groups1 = transition$$1._groups, m0 = groups0.length, m1 = groups1.length, m = Math.min(m0, m1), merges = new Array(m0), j = 0; j < m; ++j) {
            for (var group0 = groups0[j], group1 = groups1[j], n = group0.length, merge = merges[j] = new Array(n), node, i = 0; i < n; ++i) {
                if (node = group0[i] || group1[i]) {
                    merge[i] = node;
                }
            }
        }

        for (; j < m0; ++j) {
            merges[j] = groups0[j];
        }

        return new Transition(merges, this._parents, this._name, this._id);
    }

    function start(name) {
        return (name + "").trim().split(/^|\s+/).every(function(t) {
            var i = t.indexOf(".");
            if (i >= 0) t = t.slice(0, i);
            return !t || t === "start";
        });
    }

    function onFunction(id, name, listener) {
        var on0, on1, sit = start(name) ? init : set$1;
        return function() {
            var schedule$$1 = sit(this, id),
                on = schedule$$1.on;

            // If this node shared a dispatch with the previous node,
            // just assign the updated shared dispatch and we’re done!
            // Otherwise, copy-on-write.
            if (on !== on0) (on1 = (on0 = on).copy()).on(name, listener);

            schedule$$1.on = on1;
        };
    }

    function transition_on(name, listener) {
        var id = this._id;

        return arguments.length < 2
            ? get$1(this.node(), id).on.on(name)
            : this.each(onFunction(id, name, listener));
    }

    function removeFunction(id) {
        return function() {
            var parent = this.parentNode;
            for (var i in this.__transition) if (+i !== id) return;
            if (parent) parent.removeChild(this);
        };
    }

    function transition_remove() {
        return this.on("end.remove", removeFunction(this._id));
    }

    function transition_select(select) {
        var name = this._name,
            id = this._id;

        if (typeof select !== "function") select = selector(select);

        for (var groups = this._groups, m = groups.length, subgroups = new Array(m), j = 0; j < m; ++j) {
            for (var group = groups[j], n = group.length, subgroup = subgroups[j] = new Array(n), node, subnode, i = 0; i < n; ++i) {
                if ((node = group[i]) && (subnode = select.call(node, node.__data__, i, group))) {
                    if ("__data__" in node) subnode.__data__ = node.__data__;
                    subgroup[i] = subnode;
                    schedule(subgroup[i], name, id, i, subgroup, get$1(node, id));
                }
            }
        }

        return new Transition(subgroups, this._parents, name, id);
    }

    function transition_selectAll(select) {
        var name = this._name,
            id = this._id;

        if (typeof select !== "function") select = selectorAll(select);

        for (var groups = this._groups, m = groups.length, subgroups = [], parents = [], j = 0; j < m; ++j) {
            for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
                if (node = group[i]) {
                    for (var children = select.call(node, node.__data__, i, group), child, inherit = get$1(node, id), k = 0, l = children.length; k < l; ++k) {
                        if (child = children[k]) {
                            schedule(child, name, id, k, children, inherit);
                        }
                    }
                    subgroups.push(children);
                    parents.push(node);
                }
            }
        }

        return new Transition(subgroups, parents, name, id);
    }

    var Selection$1 = selection.prototype.constructor;

    function transition_selection() {
        return new Selection$1(this._groups, this._parents);
    }

    function styleRemove$1(name, interpolate$$1) {
        var value00,
            value10,
            interpolate0;
        return function() {
            var value0 = styleValue(this, name),
                value1 = (this.style.removeProperty(name), styleValue(this, name));
            return value0 === value1 ? null
                : value0 === value00 && value1 === value10 ? interpolate0
                    : interpolate0 = interpolate$$1(value00 = value0, value10 = value1);
        };
    }

    function styleRemoveEnd(name) {
        return function() {
            this.style.removeProperty(name);
        };
    }

    function styleConstant$1(name, interpolate$$1, value1) {
        var value00,
            interpolate0;
        return function() {
            var value0 = styleValue(this, name);
            return value0 === value1 ? null
                : value0 === value00 ? interpolate0
                    : interpolate0 = interpolate$$1(value00 = value0, value1);
        };
    }

    function styleFunction$1(name, interpolate$$1, value) {
        var value00,
            value10,
            interpolate0;
        return function() {
            var value0 = styleValue(this, name),
                value1 = value(this);
            if (value1 == null) value1 = (this.style.removeProperty(name), styleValue(this, name));
            return value0 === value1 ? null
                : value0 === value00 && value1 === value10 ? interpolate0
                    : interpolate0 = interpolate$$1(value00 = value0, value10 = value1);
        };
    }

    function transition_style(name, value, priority) {
        var i = (name += "") === "transform" ? interpolateTransformCss : interpolate;
        return value == null ? this
                .styleTween(name, styleRemove$1(name, i))
                .on("end.style." + name, styleRemoveEnd(name))
            : this.styleTween(name, typeof value === "function"
                ? styleFunction$1(name, i, tweenValue(this, "style." + name, value))
                : styleConstant$1(name, i, value + ""), priority);
    }

    function styleTween(name, value, priority) {
        function tween() {
            var node = this, i = value.apply(node, arguments);
            return i && function(t) {
                node.style.setProperty(name, i(t), priority);
            };
        }
        tween._value = value;
        return tween;
    }

    function transition_styleTween(name, value, priority) {
        var key = "style." + (name += "");
        if (arguments.length < 2) return (key = this.tween(key)) && key._value;
        if (value == null) return this.tween(key, null);
        if (typeof value !== "function") throw new Error;
        return this.tween(key, styleTween(name, value, priority == null ? "" : priority));
    }

    function textConstant$1(value) {
        return function() {
            this.textContent = value;
        };
    }

    function textFunction$1(value) {
        return function() {
            var value1 = value(this);
            this.textContent = value1 == null ? "" : value1;
        };
    }

    function transition_text(value) {
        return this.tween("text", typeof value === "function"
            ? textFunction$1(tweenValue(this, "text", value))
            : textConstant$1(value == null ? "" : value + ""));
    }

    function transition_transition() {
        var name = this._name,
            id0 = this._id,
            id1 = newId();

        for (var groups = this._groups, m = groups.length, j = 0; j < m; ++j) {
            for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
                if (node = group[i]) {
                    var inherit = get$1(node, id0);
                    schedule(node, name, id1, i, group, {
                        time: inherit.time + inherit.delay + inherit.duration,
                        delay: 0,
                        duration: inherit.duration,
                        ease: inherit.ease
                    });
                }
            }
        }

        return new Transition(groups, this._parents, name, id1);
    }

    var id = 0;

    function Transition(groups, parents, name, id) {
        this._groups = groups;
        this._parents = parents;
        this._name = name;
        this._id = id;
    }

    function transition(name) {
        return selection().transition(name);
    }

    function newId() {
        return ++id;
    }

    var selection_prototype = selection.prototype;

    Transition.prototype = transition.prototype = {
        constructor: Transition,
        select: transition_select,
        selectAll: transition_selectAll,
        filter: transition_filter,
        merge: transition_merge,
        selection: transition_selection,
        transition: transition_transition,
        call: selection_prototype.call,
        nodes: selection_prototype.nodes,
        node: selection_prototype.node,
        size: selection_prototype.size,
        empty: selection_prototype.empty,
        each: selection_prototype.each,
        on: transition_on,
        attr: transition_attr,
        attrTween: transition_attrTween,
        style: transition_style,
        styleTween: transition_styleTween,
        text: transition_text,
        remove: transition_remove,
        tween: transition_tween,
        delay: transition_delay,
        duration: transition_duration,
        ease: transition_ease
    };

    function linear$1(t) {
        return +t;
    }

    function quadIn(t) {
        return t * t;
    }

    function quadOut(t) {
        return t * (2 - t);
    }

    function quadInOut(t) {
        return ((t *= 2) <= 1 ? t * t : --t * (2 - t) + 1) / 2;
    }

    function cubicIn(t) {
        return t * t * t;
    }

    function cubicOut(t) {
        return --t * t * t + 1;
    }

    function cubicInOut(t) {
        return ((t *= 2) <= 1 ? t * t * t : (t -= 2) * t * t + 2) / 2;
    }

    var exponent = 3;

    var polyIn = (function custom(e) {
        e = +e;

        function polyIn(t) {
            return Math.pow(t, e);
        }

        polyIn.exponent = custom;

        return polyIn;
    })(exponent);

    var polyOut = (function custom(e) {
        e = +e;

        function polyOut(t) {
            return 1 - Math.pow(1 - t, e);
        }

        polyOut.exponent = custom;

        return polyOut;
    })(exponent);

    var polyInOut = (function custom(e) {
        e = +e;

        function polyInOut(t) {
            return ((t *= 2) <= 1 ? Math.pow(t, e) : 2 - Math.pow(2 - t, e)) / 2;
        }

        polyInOut.exponent = custom;

        return polyInOut;
    })(exponent);

    var pi = Math.PI;
    var halfPi = pi / 2;

    function sinIn(t) {
        return 1 - Math.cos(t * halfPi);
    }

    function sinOut(t) {
        return Math.sin(t * halfPi);
    }

    function sinInOut(t) {
        return (1 - Math.cos(pi * t)) / 2;
    }

    function expIn(t) {
        return Math.pow(2, 10 * t - 10);
    }

    function expOut(t) {
        return 1 - Math.pow(2, -10 * t);
    }

    function expInOut(t) {
        return ((t *= 2) <= 1 ? Math.pow(2, 10 * t - 10) : 2 - Math.pow(2, 10 - 10 * t)) / 2;
    }

    function circleIn(t) {
        return 1 - Math.sqrt(1 - t * t);
    }

    function circleOut(t) {
        return Math.sqrt(1 - --t * t);
    }

    function circleInOut(t) {
        return ((t *= 2) <= 1 ? 1 - Math.sqrt(1 - t * t) : Math.sqrt(1 - (t -= 2) * t) + 1) / 2;
    }

    var b1 = 4 / 11;
    var b2 = 6 / 11;
    var b3 = 8 / 11;
    var b4 = 3 / 4;
    var b5 = 9 / 11;
    var b6 = 10 / 11;
    var b7 = 15 / 16;
    var b8 = 21 / 22;
    var b9 = 63 / 64;
    var b0 = 1 / b1 / b1;

    function bounceIn(t) {
        return 1 - bounceOut(1 - t);
    }

    function bounceOut(t) {
        return (t = +t) < b1 ? b0 * t * t : t < b3 ? b0 * (t -= b2) * t + b4 : t < b6 ? b0 * (t -= b5) * t + b7 : b0 * (t -= b8) * t + b9;
    }

    function bounceInOut(t) {
        return ((t *= 2) <= 1 ? 1 - bounceOut(1 - t) : bounceOut(t - 1) + 1) / 2;
    }

    var overshoot = 1.70158;

    var backIn = (function custom(s) {
        s = +s;

        function backIn(t) {
            return t * t * ((s + 1) * t - s);
        }

        backIn.overshoot = custom;

        return backIn;
    })(overshoot);

    var backOut = (function custom(s) {
        s = +s;

        function backOut(t) {
            return --t * t * ((s + 1) * t + s) + 1;
        }

        backOut.overshoot = custom;

        return backOut;
    })(overshoot);

    var backInOut = (function custom(s) {
        s = +s;

        function backInOut(t) {
            return ((t *= 2) < 1 ? t * t * ((s + 1) * t - s) : (t -= 2) * t * ((s + 1) * t + s) + 2) / 2;
        }

        backInOut.overshoot = custom;

        return backInOut;
    })(overshoot);

    var tau = 2 * Math.PI;
    var amplitude = 1;
    var period = 0.3;

    var elasticIn = (function custom(a, p) {
        var s = Math.asin(1 / (a = Math.max(1, a))) * (p /= tau);

        function elasticIn(t) {
            return a * Math.pow(2, 10 * --t) * Math.sin((s - t) / p);
        }

        elasticIn.amplitude = function(a) { return custom(a, p * tau); };
        elasticIn.period = function(p) { return custom(a, p); };

        return elasticIn;
    })(amplitude, period);

    var elasticOut = (function custom(a, p) {
        var s = Math.asin(1 / (a = Math.max(1, a))) * (p /= tau);

        function elasticOut(t) {
            return 1 - a * Math.pow(2, -10 * (t = +t)) * Math.sin((t + s) / p);
        }

        elasticOut.amplitude = function(a) { return custom(a, p * tau); };
        elasticOut.period = function(p) { return custom(a, p); };

        return elasticOut;
    })(amplitude, period);

    var elasticInOut = (function custom(a, p) {
        var s = Math.asin(1 / (a = Math.max(1, a))) * (p /= tau);

        function elasticInOut(t) {
            return ((t = t * 2 - 1) < 0
                ? a * Math.pow(2, 10 * t) * Math.sin((s - t) / p)
                : 2 - a * Math.pow(2, -10 * t) * Math.sin((s + t) / p)) / 2;
        }

        elasticInOut.amplitude = function(a) { return custom(a, p * tau); };
        elasticInOut.period = function(p) { return custom(a, p); };

        return elasticInOut;
    })(amplitude, period);

    var defaultTiming = {
        time: null, // Set on use.
        delay: 0,
        duration: 250,
        ease: cubicInOut
    };

    function inherit(node, id) {
        var timing;
        while (!(timing = node.__transition) || !(timing = timing[id])) {
            if (!(node = node.parentNode)) {
                return defaultTiming.time = now(), defaultTiming;
            }
        }
        return timing;
    }

    function selection_transition(name) {
        var id,
            timing;

        if (name instanceof Transition) {
            id = name._id, name = name._name;
        } else {
            id = newId(), (timing = defaultTiming).time = now(), name = name == null ? null : name + "";
        }

        for (var groups = this._groups, m = groups.length, j = 0; j < m; ++j) {
            for (var group = groups[j], n = group.length, node, i = 0; i < n; ++i) {
                if (node = group[i]) {
                    schedule(node, name, id, i, group, timing || inherit(node, id));
                }
            }
        }

        return new Transition(groups, this._parents, name, id);
    }

    selection.prototype.interrupt = selection_interrupt;
    selection.prototype.transition = selection_transition;

    var root$1 = [null];

    function active(node, name) {
        var schedules = node.__transition,
            schedule$$1,
            i;

        if (schedules) {
            name = name == null ? null : name + "";
            for (i in schedules) {
                if ((schedule$$1 = schedules[i]).state > SCHEDULED && schedule$$1.name === name) {
                    return new Transition([[node]], root$1, name, +i);
                }
            }
        }

        return null;
    }

    function constant$4(x) {
        return function() {
            return x;
        };
    }

    function BrushEvent(target, type, selection) {
        this.target = target;
        this.type = type;
        this.selection = selection;
    }

    function nopropagation$1() {
        exports.event.stopImmediatePropagation();
    }

    function noevent$1() {
        exports.event.preventDefault();
        exports.event.stopImmediatePropagation();
    }

    var MODE_DRAG = {name: "drag"};
    var MODE_SPACE = {name: "space"};
    var MODE_HANDLE = {name: "handle"};
    var MODE_CENTER = {name: "center"};

    var X = {
        name: "x",
        handles: ["e", "w"].map(type),
        input: function(x, e) { return x && [[x[0], e[0][1]], [x[1], e[1][1]]]; },
        output: function(xy) { return xy && [xy[0][0], xy[1][0]]; }
    };

    var Y = {
        name: "y",
        handles: ["n", "s"].map(type),
        input: function(y, e) { return y && [[e[0][0], y[0]], [e[1][0], y[1]]]; },
        output: function(xy) { return xy && [xy[0][1], xy[1][1]]; }
    };

    var XY = {
        name: "xy",
        handles: ["n", "e", "s", "w", "nw", "ne", "se", "sw"].map(type),
        input: function(xy) { return xy; },
        output: function(xy) { return xy; }
    };

    var cursors = {
        overlay: "crosshair",
        selection: "move",
        n: "ns-resize",
        e: "ew-resize",
        s: "ns-resize",
        w: "ew-resize",
        nw: "nwse-resize",
        ne: "nesw-resize",
        se: "nwse-resize",
        sw: "nesw-resize"
    };

    var flipX = {
        e: "w",
        w: "e",
        nw: "ne",
        ne: "nw",
        se: "sw",
        sw: "se"
    };

    var flipY = {
        n: "s",
        s: "n",
        nw: "sw",
        ne: "se",
        se: "ne",
        sw: "nw"
    };

    var signsX = {
        overlay: +1,
        selection: +1,
        n: null,
        e: +1,
        s: null,
        w: -1,
        nw: -1,
        ne: +1,
        se: +1,
        sw: -1
    };

    var signsY = {
        overlay: +1,
        selection: +1,
        n: -1,
        e: null,
        s: +1,
        w: null,
        nw: -1,
        ne: -1,
        se: +1,
        sw: +1
    };

    function type(t) {
        return {type: t};
    }

// Ignore right-click, since that should open the context menu.
    function defaultFilter() {
        return !exports.event.button;
    }

    function defaultExtent() {
        var svg = this.ownerSVGElement || this;
        return [[0, 0], [svg.width.baseVal.value, svg.height.baseVal.value]];
    }

// Like d3.local, but with the name “__brush” rather than auto-generated.
    function local(node) {
        while (!node.__brush) if (!(node = node.parentNode)) return;
        return node.__brush;
    }

    function empty(extent) {
        return extent[0][0] === extent[1][0]
            || extent[0][1] === extent[1][1];
    }

    function brushSelection(node) {
        var state = node.__brush;
        return state ? state.dim.output(state.selection) : null;
    }

    function brushX() {
        return brush$1(X);
    }

    function brushY() {
        return brush$1(Y);
    }

    function brush() {
        return brush$1(XY);
    }

    function brush$1(dim) {
        var extent = defaultExtent,
            filter = defaultFilter,
            listeners = dispatch(brush, "start", "brush", "end"),
            handleSize = 6,
            touchending;

        function brush(group) {
            var overlay = group
                .property("__brush", initialize)
                .selectAll(".overlay")
                .data([type("overlay")]);

            overlay.enter().append("rect")
                .attr("class", "overlay")
                .attr("pointer-events", "all")
                .attr("cursor", cursors.overlay)
                .merge(overlay)
                .each(function() {
                    var extent = local(this).extent;
                    select(this)
                        .attr("x", extent[0][0])
                        .attr("y", extent[0][1])
                        .attr("width", extent[1][0] - extent[0][0])
                        .attr("height", extent[1][1] - extent[0][1]);
                });

            group.selectAll(".selection")
                .data([type("selection")])
                .enter().append("rect")
                .attr("class", "selection")
                .attr("cursor", cursors.selection)
                .attr("fill", "#777")
                .attr("fill-opacity", 0.3)
                .attr("stroke", "#fff")
                .attr("shape-rendering", "crispEdges");

            var handle = group.selectAll(".handle")
                .data(dim.handles, function(d) { return d.type; });

            handle.exit().remove();

            handle.enter().append("rect")
                .attr("class", function(d) { return "handle handle--" + d.type; })
                .attr("cursor", function(d) { return cursors[d.type]; });

            group
                .each(redraw)
                .attr("fill", "none")
                .attr("pointer-events", "all")
                .style("-webkit-tap-highlight-color", "rgba(0,0,0,0)")
                .on("mousedown.brush touchstart.brush", started);
        }

        brush.move = function(group, selection) {
            if (group.selection) {
                group
                    .on("start.brush", function() { emitter(this, arguments).beforestart().start(); })
                    .on("interrupt.brush end.brush", function() { emitter(this, arguments).end(); })
                    .tween("brush", function() {
                        var that = this,
                            state = that.__brush,
                            emit = emitter(that, arguments),
                            selection0 = state.selection,
                            selection1 = dim.input(typeof selection === "function" ? selection.apply(this, arguments) : selection, state.extent),
                            i = interpolateValue(selection0, selection1);

                        function tween(t) {
                            state.selection = t === 1 && empty(selection1) ? null : i(t);
                            redraw.call(that);
                            emit.brush();
                        }

                        return selection0 && selection1 ? tween : tween(1);
                    });
            } else {
                group
                    .each(function() {
                        var that = this,
                            args = arguments,
                            state = that.__brush,
                            selection1 = dim.input(typeof selection === "function" ? selection.apply(that, args) : selection, state.extent),
                            emit = emitter(that, args).beforestart();

                        interrupt(that);
                        state.selection = selection1 == null || empty(selection1) ? null : selection1;
                        redraw.call(that);
                        emit.start().brush().end();
                    });
            }
        };

        function redraw() {
            var group = select(this),
                selection = local(this).selection;

            if (selection) {
                group.selectAll(".selection")
                    .style("display", null)
                    .attr("x", selection[0][0])
                    .attr("y", selection[0][1])
                    .attr("width", selection[1][0] - selection[0][0])
                    .attr("height", selection[1][1] - selection[0][1]);

                group.selectAll(".handle")
                    .style("display", null)
                    .attr("x", function(d) { return d.type[d.type.length - 1] === "e" ? selection[1][0] - handleSize / 2 : selection[0][0] - handleSize / 2; })
                    .attr("y", function(d) { return d.type[0] === "s" ? selection[1][1] - handleSize / 2 : selection[0][1] - handleSize / 2; })
                    .attr("width", function(d) { return d.type === "n" || d.type === "s" ? selection[1][0] - selection[0][0] + handleSize : handleSize; })
                    .attr("height", function(d) { return d.type === "e" || d.type === "w" ? selection[1][1] - selection[0][1] + handleSize : handleSize; });
            }

            else {
                group.selectAll(".selection,.handle")
                    .style("display", "none")
                    .attr("x", null)
                    .attr("y", null)
                    .attr("width", null)
                    .attr("height", null);
            }
        }

        function emitter(that, args) {
            return that.__brush.emitter || new Emitter(that, args);
        }

        function Emitter(that, args) {
            this.that = that;
            this.args = args;
            this.state = that.__brush;
            this.active = 0;
        }

        Emitter.prototype = {
            beforestart: function() {
                if (++this.active === 1) this.state.emitter = this, this.starting = true;
                return this;
            },
            start: function() {
                if (this.starting) this.starting = false, this.emit("start");
                return this;
            },
            brush: function() {
                this.emit("brush");
                return this;
            },
            end: function() {
                if (--this.active === 0) delete this.state.emitter, this.emit("end");
                return this;
            },
            emit: function(type) {
                customEvent(new BrushEvent(brush, type, dim.output(this.state.selection)), listeners.apply, listeners, [type, this.that, this.args]);
            }
        };

        function started() {
            if (exports.event.touches) { if (exports.event.changedTouches.length < exports.event.touches.length) return noevent$1(); }
            else if (touchending) return;
            if (!filter.apply(this, arguments)) return;

            var that = this,
                type = exports.event.target.__data__.type,
                mode = (exports.event.metaKey ? type = "overlay" : type) === "selection" ? MODE_DRAG : (exports.event.altKey ? MODE_CENTER : MODE_HANDLE),
                signX = dim === Y ? null : signsX[type],
                signY = dim === X ? null : signsY[type],
                state = local(that),
                extent = state.extent,
                selection = state.selection,
                W = extent[0][0], w0, w1,
                N = extent[0][1], n0, n1,
                E = extent[1][0], e0, e1,
                S = extent[1][1], s0, s1,
                dx,
                dy,
                moving,
                shifting = signX && signY && exports.event.shiftKey,
                lockX,
                lockY,
                point0 = mouse(that),
                point = point0,
                emit = emitter(that, arguments).beforestart();

            if (type === "overlay") {
                state.selection = selection = [
                    [w0 = dim === Y ? W : point0[0], n0 = dim === X ? N : point0[1]],
                    [e0 = dim === Y ? E : w0, s0 = dim === X ? S : n0]
                ];
            } else {
                w0 = selection[0][0];
                n0 = selection[0][1];
                e0 = selection[1][0];
                s0 = selection[1][1];
            }

            w1 = w0;
            n1 = n0;
            e1 = e0;
            s1 = s0;

            var group = select(that)
                .attr("pointer-events", "none");

            var overlay = group.selectAll(".overlay")
                .attr("cursor", cursors[type]);

            if (exports.event.touches) {
                group
                    .on("touchmove.brush", moved, true)
                    .on("touchend.brush touchcancel.brush", ended, true);
            } else {
                var view = select(exports.event.view)
                    .on("keydown.brush", keydowned, true)
                    .on("keyup.brush", keyupped, true)
                    .on("mousemove.brush", moved, true)
                    .on("mouseup.brush", ended, true);

                dragDisable(exports.event.view);
            }

            nopropagation$1();
            interrupt(that);
            redraw.call(that);
            emit.start();

            function moved() {
                var point1 = mouse(that);
                if (shifting && !lockX && !lockY) {
                    if (Math.abs(point1[0] - point[0]) > Math.abs(point1[1] - point[1])) lockY = true;
                    else lockX = true;
                }
                point = point1;
                moving = true;
                noevent$1();
                move();
            }

            function move() {
                var t;

                dx = point[0] - point0[0];
                dy = point[1] - point0[1];

                switch (mode) {
                    case MODE_SPACE:
                    case MODE_DRAG: {
                        if (signX) dx = Math.max(W - w0, Math.min(E - e0, dx)), w1 = w0 + dx, e1 = e0 + dx;
                        if (signY) dy = Math.max(N - n0, Math.min(S - s0, dy)), n1 = n0 + dy, s1 = s0 + dy;
                        break;
                    }
                    case MODE_HANDLE: {
                        if (signX < 0) dx = Math.max(W - w0, Math.min(E - w0, dx)), w1 = w0 + dx, e1 = e0;
                        else if (signX > 0) dx = Math.max(W - e0, Math.min(E - e0, dx)), w1 = w0, e1 = e0 + dx;
                        if (signY < 0) dy = Math.max(N - n0, Math.min(S - n0, dy)), n1 = n0 + dy, s1 = s0;
                        else if (signY > 0) dy = Math.max(N - s0, Math.min(S - s0, dy)), n1 = n0, s1 = s0 + dy;
                        break;
                    }
                    case MODE_CENTER: {
                        if (signX) w1 = Math.max(W, Math.min(E, w0 - dx * signX)), e1 = Math.max(W, Math.min(E, e0 + dx * signX));
                        if (signY) n1 = Math.max(N, Math.min(S, n0 - dy * signY)), s1 = Math.max(N, Math.min(S, s0 + dy * signY));
                        break;
                    }
                }

                if (e1 < w1) {
                    signX *= -1;
                    t = w0, w0 = e0, e0 = t;
                    t = w1, w1 = e1, e1 = t;
                    if (type in flipX) overlay.attr("cursor", cursors[type = flipX[type]]);
                }

                if (s1 < n1) {
                    signY *= -1;
                    t = n0, n0 = s0, s0 = t;
                    t = n1, n1 = s1, s1 = t;
                    if (type in flipY) overlay.attr("cursor", cursors[type = flipY[type]]);
                }

                if (state.selection) selection = state.selection; // May be set by brush.move!
                if (lockX) w1 = selection[0][0], e1 = selection[1][0];
                if (lockY) n1 = selection[0][1], s1 = selection[1][1];

                if (selection[0][0] !== w1
                    || selection[0][1] !== n1
                    || selection[1][0] !== e1
                    || selection[1][1] !== s1) {
                    state.selection = [[w1, n1], [e1, s1]];
                    redraw.call(that);
                    emit.brush();
                }
            }

            function ended() {
                nopropagation$1();
                if (exports.event.touches) {
                    if (exports.event.touches.length) return;
                    if (touchending) clearTimeout(touchending);
                    touchending = setTimeout(function() { touchending = null; }, 500); // Ghost clicks are delayed!
                    group.on("touchmove.brush touchend.brush touchcancel.brush", null);
                } else {
                    yesdrag(exports.event.view, moving);
                    view.on("keydown.brush keyup.brush mousemove.brush mouseup.brush", null);
                }
                group.attr("pointer-events", "all");
                overlay.attr("cursor", cursors.overlay);
                if (state.selection) selection = state.selection; // May be set by brush.move (on start)!
                if (empty(selection)) state.selection = null, redraw.call(that);
                emit.end();
            }

            function keydowned() {
                switch (exports.event.keyCode) {
                    case 16: { // SHIFT
                        shifting = signX && signY;
                        break;
                    }
                    case 18: { // ALT
                        if (mode === MODE_HANDLE) {
                            if (signX) e0 = e1 - dx * signX, w0 = w1 + dx * signX;
                            if (signY) s0 = s1 - dy * signY, n0 = n1 + dy * signY;
                            mode = MODE_CENTER;
                            move();
                        }
                        break;
                    }
                    case 32: { // SPACE; takes priority over ALT
                        if (mode === MODE_HANDLE || mode === MODE_CENTER) {
                            if (signX < 0) e0 = e1 - dx; else if (signX > 0) w0 = w1 - dx;
                            if (signY < 0) s0 = s1 - dy; else if (signY > 0) n0 = n1 - dy;
                            mode = MODE_SPACE;
                            overlay.attr("cursor", cursors.selection);
                            move();
                        }
                        break;
                    }
                    default: return;
                }
                noevent$1();
            }

            function keyupped() {
                switch (exports.event.keyCode) {
                    case 16: { // SHIFT
                        if (shifting) {
                            lockX = lockY = shifting = false;
                            move();
                        }
                        break;
                    }
                    case 18: { // ALT
                        if (mode === MODE_CENTER) {
                            if (signX < 0) e0 = e1; else if (signX > 0) w0 = w1;
                            if (signY < 0) s0 = s1; else if (signY > 0) n0 = n1;
                            mode = MODE_HANDLE;
                            move();
                        }
                        break;
                    }
                    case 32: { // SPACE
                        if (mode === MODE_SPACE) {
                            if (exports.event.altKey) {
                                if (signX) e0 = e1 - dx * signX, w0 = w1 + dx * signX;
                                if (signY) s0 = s1 - dy * signY, n0 = n1 + dy * signY;
                                mode = MODE_CENTER;
                            } else {
                                if (signX < 0) e0 = e1; else if (signX > 0) w0 = w1;
                                if (signY < 0) s0 = s1; else if (signY > 0) n0 = n1;
                                mode = MODE_HANDLE;
                            }
                            overlay.attr("cursor", cursors[type]);
                            move();
                        }
                        break;
                    }
                    default: return;
                }
                noevent$1();
            }
        }

        function initialize() {
            var state = this.__brush || {selection: null};
            state.extent = extent.apply(this, arguments);
            state.dim = dim;
            return state;
        }

        brush.extent = function(_) {
            return arguments.length ? (extent = typeof _ === "function" ? _ : constant$4([[+_[0][0], +_[0][1]], [+_[1][0], +_[1][1]]]), brush) : extent;
        };

        brush.filter = function(_) {
            return arguments.length ? (filter = typeof _ === "function" ? _ : constant$4(!!_), brush) : filter;
        };

        brush.handleSize = function(_) {
            return arguments.length ? (handleSize = +_, brush) : handleSize;
        };

        brush.on = function() {
            var value = listeners.on.apply(listeners, arguments);
            return value === listeners ? brush : value;
        };

        return brush;
    }

    var cos = Math.cos;
    var sin = Math.sin;
    var pi$1 = Math.PI;
    var halfPi$1 = pi$1 / 2;
    var tau$1 = pi$1 * 2;
    var max$1 = Math.max;

    function compareValue(compare) {
        return function(a, b) {
            return compare(
                a.source.value + a.target.value,
                b.source.value + b.target.value
            );
        };
    }

    function chord() {
        var padAngle = 0,
            sortGroups = null,
            sortSubgroups = null,
            sortChords = null;

        function chord(matrix) {
            var n = matrix.length,
                groupSums = [],
                groupIndex = sequence(n),
                subgroupIndex = [],
                chords = [],
                groups = chords.groups = new Array(n),
                subgroups = new Array(n * n),
                k,
                x,
                x0,
                dx,
                i,
                j;

            // Compute the sum.
            k = 0, i = -1; while (++i < n) {
                x = 0, j = -1; while (++j < n) {
                    x += matrix[i][j];
                }
                groupSums.push(x);
                subgroupIndex.push(sequence(n));
                k += x;
            }

            // Sort groups…
            if (sortGroups) groupIndex.sort(function(a, b) {
                return sortGroups(groupSums[a], groupSums[b]);
            });

            // Sort subgroups…
            if (sortSubgroups) subgroupIndex.forEach(function(d, i) {
                d.sort(function(a, b) {
                    return sortSubgroups(matrix[i][a], matrix[i][b]);
                });
            });

            // Convert the sum to scaling factor for [0, 2pi].
            // TODO Allow start and end angle to be specified?
            // TODO Allow padding to be specified as percentage?
            k = max$1(0, tau$1 - padAngle * n) / k;
            dx = k ? padAngle : tau$1 / n;

            // Compute the start and end angle for each group and subgroup.
            // Note: Opera has a bug reordering object literal properties!
            x = 0, i = -1; while (++i < n) {
                x0 = x, j = -1; while (++j < n) {
                    var di = groupIndex[i],
                        dj = subgroupIndex[di][j],
                        v = matrix[di][dj],
                        a0 = x,
                        a1 = x += v * k;
                    subgroups[dj * n + di] = {
                        index: di,
                        subindex: dj,
                        startAngle: a0,
                        endAngle: a1,
                        value: v
                    };
                }
                groups[di] = {
                    index: di,
                    startAngle: x0,
                    endAngle: x,
                    value: groupSums[di]
                };
                x += dx;
            }

            // Generate chords for each (non-empty) subgroup-subgroup link.
            i = -1; while (++i < n) {
                j = i - 1; while (++j < n) {
                    var source = subgroups[j * n + i],
                        target = subgroups[i * n + j];
                    if (source.value || target.value) {
                        chords.push(source.value < target.value
                            ? {source: target, target: source}
                            : {source: source, target: target});
                    }
                }
            }

            return sortChords ? chords.sort(sortChords) : chords;
        }

        chord.padAngle = function(_) {
            return arguments.length ? (padAngle = max$1(0, _), chord) : padAngle;
        };

        chord.sortGroups = function(_) {
            return arguments.length ? (sortGroups = _, chord) : sortGroups;
        };

        chord.sortSubgroups = function(_) {
            return arguments.length ? (sortSubgroups = _, chord) : sortSubgroups;
        };

        chord.sortChords = function(_) {
            return arguments.length ? (_ == null ? sortChords = null : (sortChords = compareValue(_))._ = _, chord) : sortChords && sortChords._;
        };

        return chord;
    }

    var slice$2 = Array.prototype.slice;

    function constant$5(x) {
        return function() {
            return x;
        };
    }

    var pi$2 = Math.PI;
    var tau$2 = 2 * pi$2;
    var epsilon$1 = 1e-6;
    var tauEpsilon = tau$2 - epsilon$1;

    function Path() {
        this._x0 = this._y0 = // start of current subpath
            this._x1 = this._y1 = null; // end of current subpath
        this._ = "";
    }

    function path() {
        return new Path;
    }

    Path.prototype = path.prototype = {
        constructor: Path,
        moveTo: function(x, y) {
            this._ += "M" + (this._x0 = this._x1 = +x) + "," + (this._y0 = this._y1 = +y);
        },
        closePath: function() {
            if (this._x1 !== null) {
                this._x1 = this._x0, this._y1 = this._y0;
                this._ += "Z";
            }
        },
        lineTo: function(x, y) {
            this._ += "L" + (this._x1 = +x) + "," + (this._y1 = +y);
        },
        quadraticCurveTo: function(x1, y1, x, y) {
            this._ += "Q" + (+x1) + "," + (+y1) + "," + (this._x1 = +x) + "," + (this._y1 = +y);
        },
        bezierCurveTo: function(x1, y1, x2, y2, x, y) {
            this._ += "C" + (+x1) + "," + (+y1) + "," + (+x2) + "," + (+y2) + "," + (this._x1 = +x) + "," + (this._y1 = +y);
        },
        arcTo: function(x1, y1, x2, y2, r) {
            x1 = +x1, y1 = +y1, x2 = +x2, y2 = +y2, r = +r;
            var x0 = this._x1,
                y0 = this._y1,
                x21 = x2 - x1,
                y21 = y2 - y1,
                x01 = x0 - x1,
                y01 = y0 - y1,
                l01_2 = x01 * x01 + y01 * y01;

            // Is the radius negative? Error.
            if (r < 0) throw new Error("negative radius: " + r);

            // Is this path empty? Move to (x1,y1).
            if (this._x1 === null) {
                this._ += "M" + (this._x1 = x1) + "," + (this._y1 = y1);
            }

            // Or, is (x1,y1) coincident with (x0,y0)? Do nothing.
            else if (!(l01_2 > epsilon$1)) {}

                // Or, are (x0,y0), (x1,y1) and (x2,y2) collinear?
                // Equivalently, is (x1,y1) coincident with (x2,y2)?
            // Or, is the radius zero? Line to (x1,y1).
            else if (!(Math.abs(y01 * x21 - y21 * x01) > epsilon$1) || !r) {
                this._ += "L" + (this._x1 = x1) + "," + (this._y1 = y1);
            }

            // Otherwise, draw an arc!
            else {
                var x20 = x2 - x0,
                    y20 = y2 - y0,
                    l21_2 = x21 * x21 + y21 * y21,
                    l20_2 = x20 * x20 + y20 * y20,
                    l21 = Math.sqrt(l21_2),
                    l01 = Math.sqrt(l01_2),
                    l = r * Math.tan((pi$2 - Math.acos((l21_2 + l01_2 - l20_2) / (2 * l21 * l01))) / 2),
                    t01 = l / l01,
                    t21 = l / l21;

                // If the start tangent is not coincident with (x0,y0), line to.
                if (Math.abs(t01 - 1) > epsilon$1) {
                    this._ += "L" + (x1 + t01 * x01) + "," + (y1 + t01 * y01);
                }

                this._ += "A" + r + "," + r + ",0,0," + (+(y01 * x20 > x01 * y20)) + "," + (this._x1 = x1 + t21 * x21) + "," + (this._y1 = y1 + t21 * y21);
            }
        },
        arc: function(x, y, r, a0, a1, ccw) {
            x = +x, y = +y, r = +r;
            var dx = r * Math.cos(a0),
                dy = r * Math.sin(a0),
                x0 = x + dx,
                y0 = y + dy,
                cw = 1 ^ ccw,
                da = ccw ? a0 - a1 : a1 - a0;

            // Is the radius negative? Error.
            if (r < 0) throw new Error("negative radius: " + r);

            // Is this path empty? Move to (x0,y0).
            if (this._x1 === null) {
                this._ += "M" + x0 + "," + y0;
            }

            // Or, is (x0,y0) not coincident with the previous point? Line to (x0,y0).
            else if (Math.abs(this._x1 - x0) > epsilon$1 || Math.abs(this._y1 - y0) > epsilon$1) {
                this._ += "L" + x0 + "," + y0;
            }

            // Is this arc empty? We’re done.
            if (!r) return;

            // Does the angle go the wrong way? Flip the direction.
            if (da < 0) da = da % tau$2 + tau$2;

            // Is this a complete circle? Draw two arcs to complete the circle.
            if (da > tauEpsilon) {
                this._ += "A" + r + "," + r + ",0,1," + cw + "," + (x - dx) + "," + (y - dy) + "A" + r + "," + r + ",0,1," + cw + "," + (this._x1 = x0) + "," + (this._y1 = y0);
            }

            // Is this arc non-empty? Draw an arc!
            else if (da > epsilon$1) {
                this._ += "A" + r + "," + r + ",0," + (+(da >= pi$2)) + "," + cw + "," + (this._x1 = x + r * Math.cos(a1)) + "," + (this._y1 = y + r * Math.sin(a1));
            }
        },
        rect: function(x, y, w, h) {
            this._ += "M" + (this._x0 = this._x1 = +x) + "," + (this._y0 = this._y1 = +y) + "h" + (+w) + "v" + (+h) + "h" + (-w) + "Z";
        },
        toString: function() {
            return this._;
        }
    };

    function defaultSource(d) {
        return d.source;
    }

    function defaultTarget(d) {
        return d.target;
    }

    function defaultRadius(d) {
        return d.radius;
    }

    function defaultStartAngle(d) {
        return d.startAngle;
    }

    function defaultEndAngle(d) {
        return d.endAngle;
    }

    function ribbon() {
        var source = defaultSource,
            target = defaultTarget,
            radius = defaultRadius,
            startAngle = defaultStartAngle,
            endAngle = defaultEndAngle,
            context = null;

        function ribbon() {
            var buffer,
                argv = slice$2.call(arguments),
                s = source.apply(this, argv),
                t = target.apply(this, argv),
                sr = +radius.apply(this, (argv[0] = s, argv)),
                sa0 = startAngle.apply(this, argv) - halfPi$1,
                sa1 = endAngle.apply(this, argv) - halfPi$1,
                sx0 = sr * cos(sa0),
                sy0 = sr * sin(sa0),
                tr = +radius.apply(this, (argv[0] = t, argv)),
                ta0 = startAngle.apply(this, argv) - halfPi$1,
                ta1 = endAngle.apply(this, argv) - halfPi$1;

            if (!context) context = buffer = path();

            context.moveTo(sx0, sy0);
            context.arc(0, 0, sr, sa0, sa1);
            if (sa0 !== ta0 || sa1 !== ta1) { // TODO sr !== tr?
                context.quadraticCurveTo(0, 0, tr * cos(ta0), tr * sin(ta0));
                context.arc(0, 0, tr, ta0, ta1);
            }
            context.quadraticCurveTo(0, 0, sx0, sy0);
            context.closePath();

            if (buffer) return context = null, buffer + "" || null;
        }

        ribbon.radius = function(_) {
            return arguments.length ? (radius = typeof _ === "function" ? _ : constant$5(+_), ribbon) : radius;
        };

        ribbon.startAngle = function(_) {
            return arguments.length ? (startAngle = typeof _ === "function" ? _ : constant$5(+_), ribbon) : startAngle;
        };

        ribbon.endAngle = function(_) {
            return arguments.length ? (endAngle = typeof _ === "function" ? _ : constant$5(+_), ribbon) : endAngle;
        };

        ribbon.source = function(_) {
            return arguments.length ? (source = _, ribbon) : source;
        };

        ribbon.target = function(_) {
            return arguments.length ? (target = _, ribbon) : target;
        };

        ribbon.context = function(_) {
            return arguments.length ? (context = _ == null ? null : _, ribbon) : context;
        };

        return ribbon;
    }

    var prefix = "$";

    function Map() {}

    Map.prototype = map$1.prototype = {
        constructor: Map,
        has: function(key) {
            return (prefix + key) in this;
        },
        get: function(key) {
            return this[prefix + key];
        },
        set: function(key, value) {
            this[prefix + key] = value;
            return this;
        },
        remove: function(key) {
            var property = prefix + key;
            return property in this && delete this[property];
        },
        clear: function() {
            for (var property in this) if (property[0] === prefix) delete this[property];
        },
        keys: function() {
            var keys = [];
            for (var property in this) if (property[0] === prefix) keys.push(property.slice(1));
            return keys;
        },
        values: function() {
            var values = [];
            for (var property in this) if (property[0] === prefix) values.push(this[property]);
            return values;
        },
        entries: function() {
            var entries = [];
            for (var property in this) if (property[0] === prefix) entries.push({key: property.slice(1), value: this[property]});
            return entries;
        },
        size: function() {
            var size = 0;
            for (var property in this) if (property[0] === prefix) ++size;
            return size;
        },
        empty: function() {
            for (var property in this) if (property[0] === prefix) return false;
            return true;
        },
        each: function(f) {
            for (var property in this) if (property[0] === prefix) f(this[property], property.slice(1), this);
        }
    };

    function map$1(object, f) {
        var map = new Map;

        // Copy constructor.
        if (object instanceof Map) object.each(function(value, key) { map.set(key, value); });

        // Index array by numeric index or specified key function.
        else if (Array.isArray(object)) {
            var i = -1,
                n = object.length,
                o;

            if (f == null) while (++i < n) map.set(i, object[i]);
            else while (++i < n) map.set(f(o = object[i], i, object), o);
        }

        // Convert object to map.
        else if (object) for (var key in object) map.set(key, object[key]);

        return map;
    }

    function nest() {
        var keys = [],
            sortKeys = [],
            sortValues,
            rollup,
            nest;

        function apply(array, depth, createResult, setResult) {
            if (depth >= keys.length) {
                if (sortValues != null) array.sort(sortValues);
                return rollup != null ? rollup(array) : array;
            }

            var i = -1,
                n = array.length,
                key = keys[depth++],
                keyValue,
                value,
                valuesByKey = map$1(),
                values,
                result = createResult();

            while (++i < n) {
                if (values = valuesByKey.get(keyValue = key(value = array[i]) + "")) {
                    values.push(value);
                } else {
                    valuesByKey.set(keyValue, [value]);
                }
            }

            valuesByKey.each(function(values, key) {
                setResult(result, key, apply(values, depth, createResult, setResult));
            });

            return result;
        }

        function entries(map, depth) {
            if (++depth > keys.length) return map;
            var array, sortKey = sortKeys[depth - 1];
            if (rollup != null && depth >= keys.length) array = map.entries();
            else array = [], map.each(function(v, k) { array.push({key: k, values: entries(v, depth)}); });
            return sortKey != null ? array.sort(function(a, b) { return sortKey(a.key, b.key); }) : array;
        }

        return nest = {
            object: function(array) { return apply(array, 0, createObject, setObject); },
            map: function(array) { return apply(array, 0, createMap, setMap); },
            entries: function(array) { return entries(apply(array, 0, createMap, setMap), 0); },
            key: function(d) { keys.push(d); return nest; },
            sortKeys: function(order) { sortKeys[keys.length - 1] = order; return nest; },
            sortValues: function(order) { sortValues = order; return nest; },
            rollup: function(f) { rollup = f; return nest; }
        };
    }

    function createObject() {
        return {};
    }

    function setObject(object, key, value) {
        object[key] = value;
    }

    function createMap() {
        return map$1();
    }

    function setMap(map, key, value) {
        map.set(key, value);
    }

    function Set() {}

    var proto = map$1.prototype;

    Set.prototype = set$2.prototype = {
        constructor: Set,
        has: proto.has,
        add: function(value) {
            value += "";
            this[prefix + value] = value;
            return this;
        },
        remove: proto.remove,
        clear: proto.clear,
        values: proto.keys,
        size: proto.size,
        empty: proto.empty,
        each: proto.each
    };

    function set$2(object, f) {
        var set = new Set;

        // Copy constructor.
        if (object instanceof Set) object.each(function(value) { set.add(value); });

        // Otherwise, assume it’s an array.
        else if (object) {
            var i = -1, n = object.length;
            if (f == null) while (++i < n) set.add(object[i]);
            else while (++i < n) set.add(f(object[i], i, object));
        }

        return set;
    }

    function keys(map) {
        var keys = [];
        for (var key in map) keys.push(key);
        return keys;
    }

    function values(map) {
        var values = [];
        for (var key in map) values.push(map[key]);
        return values;
    }

    function entries(map) {
        var entries = [];
        for (var key in map) entries.push({key: key, value: map[key]});
        return entries;
    }

    var EOL = {};
    var EOF = {};
    var QUOTE = 34;
    var NEWLINE = 10;
    var RETURN = 13;

    function objectConverter(columns) {
        return new Function("d", "return {" + columns.map(function(name, i) {
            return JSON.stringify(name) + ": d[" + i + "]";
        }).join(",") + "}");
    }

    function customConverter(columns, f) {
        var object = objectConverter(columns);
        return function(row, i) {
            return f(object(row), i, columns);
        };
    }

// Compute unique columns in order of discovery.
    function inferColumns(rows) {
        var columnSet = Object.create(null),
            columns = [];

        rows.forEach(function(row) {
            for (var column in row) {
                if (!(column in columnSet)) {
                    columns.push(columnSet[column] = column);
                }
            }
        });

        return columns;
    }

    function dsv(delimiter) {
        var reFormat = new RegExp("[\"" + delimiter + "\n\r]"),
            DELIMITER = delimiter.charCodeAt(0);

        function parse(text, f) {
            var convert, columns, rows = parseRows(text, function(row, i) {
                if (convert) return convert(row, i - 1);
                columns = row, convert = f ? customConverter(row, f) : objectConverter(row);
            });
            rows.columns = columns || [];
            return rows;
        }

        function parseRows(text, f) {
            var rows = [], // output rows
                N = text.length,
                I = 0, // current character index
                n = 0, // current line number
                t, // current token
                eof = N <= 0, // current token followed by EOF?
                eol = false; // current token followed by EOL?

            // Strip the trailing newline.
            if (text.charCodeAt(N - 1) === NEWLINE) --N;
            if (text.charCodeAt(N - 1) === RETURN) --N;

            function token() {
                if (eof) return EOF;
                if (eol) return eol = false, EOL;

                // Unescape quotes.
                var i, j = I, c;
                if (text.charCodeAt(j) === QUOTE) {
                    while (I++ < N && text.charCodeAt(I) !== QUOTE || text.charCodeAt(++I) === QUOTE);
                    if ((i = I) >= N) eof = true;
                    else if ((c = text.charCodeAt(I++)) === NEWLINE) eol = true;
                    else if (c === RETURN) { eol = true; if (text.charCodeAt(I) === NEWLINE) ++I; }
                    return text.slice(j + 1, i - 1).replace(/""/g, "\"");
                }

                // Find next delimiter or newline.
                while (I < N) {
                    if ((c = text.charCodeAt(i = I++)) === NEWLINE) eol = true;
                    else if (c === RETURN) { eol = true; if (text.charCodeAt(I) === NEWLINE) ++I; }
                    else if (c !== DELIMITER) continue;
                    return text.slice(j, i);
                }

                // Return last token before EOF.
                return eof = true, text.slice(j, N);
            }

            while ((t = token()) !== EOF) {
                var row = [];
                while (t !== EOL && t !== EOF) row.push(t), t = token();
                if (f && (row = f(row, n++)) == null) continue;
                rows.push(row);
            }

            return rows;
        }

        function format(rows, columns) {
            if (columns == null) columns = inferColumns(rows);
            return [columns.map(formatValue).join(delimiter)].concat(rows.map(function(row) {
                return columns.map(function(column) {
                    return formatValue(row[column]);
                }).join(delimiter);
            })).join("\n");
        }

        function formatRows(rows) {
            return rows.map(formatRow).join("\n");
        }

        function formatRow(row) {
            return row.map(formatValue).join(delimiter);
        }

        function formatValue(text) {
            return text == null ? ""
                : reFormat.test(text += "") ? "\"" + text.replace(/"/g, "\"\"") + "\""
                    : text;
        }

        return {
            parse: parse,
            parseRows: parseRows,
            format: format,
            formatRows: formatRows
        };
    }

    var csv = dsv(",");

    var csvParse = csv.parse;
    var csvParseRows = csv.parseRows;
    var csvFormat = csv.format;
    var csvFormatRows = csv.formatRows;

    var tsv = dsv("\t");

    var tsvParse = tsv.parse;
    var tsvParseRows = tsv.parseRows;
    var tsvFormat = tsv.format;
    var tsvFormatRows = tsv.formatRows;

    function center$1(x, y) {
        var nodes;

        if (x == null) x = 0;
        if (y == null) y = 0;

        function force() {
            var i,
                n = nodes.length,
                node,
                sx = 0,
                sy = 0;

            for (i = 0; i < n; ++i) {
                node = nodes[i], sx += node.x, sy += node.y;
            }

            for (sx = sx / n - x, sy = sy / n - y, i = 0; i < n; ++i) {
                node = nodes[i], node.x -= sx, node.y -= sy;
            }
        }

        force.initialize = function(_) {
            nodes = _;
        };

        force.x = function(_) {
            return arguments.length ? (x = +_, force) : x;
        };

        force.y = function(_) {
            return arguments.length ? (y = +_, force) : y;
        };

        return force;
    }

    function constant$6(x) {
        return function() {
            return x;
        };
    }

    function jiggle() {
        return (Math.random() - 0.5) * 1e-6;
    }

    function tree_add(d) {
        var x = +this._x.call(null, d),
            y = +this._y.call(null, d);
        return add(this.cover(x, y), x, y, d);
    }

    function add(tree, x, y, d) {
        if (isNaN(x) || isNaN(y)) return tree; // ignore invalid points

        var parent,
            node = tree._root,
            leaf = {data: d},
            x0 = tree._x0,
            y0 = tree._y0,
            x1 = tree._x1,
            y1 = tree._y1,
            xm,
            ym,
            xp,
            yp,
            right,
            bottom,
            i,
            j;

        // If the tree is empty, initialize the root as a leaf.
        if (!node) return tree._root = leaf, tree;

        // Find the existing leaf for the new point, or add it.
        while (node.length) {
            if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
            if (bottom = y >= (ym = (y0 + y1) / 2)) y0 = ym; else y1 = ym;
            if (parent = node, !(node = node[i = bottom << 1 | right])) return parent[i] = leaf, tree;
        }

        // Is the new point is exactly coincident with the existing point?
        xp = +tree._x.call(null, node.data);
        yp = +tree._y.call(null, node.data);
        if (x === xp && y === yp) return leaf.next = node, parent ? parent[i] = leaf : tree._root = leaf, tree;

        // Otherwise, split the leaf node until the old and new point are separated.
        do {
            parent = parent ? parent[i] = new Array(4) : tree._root = new Array(4);
            if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
            if (bottom = y >= (ym = (y0 + y1) / 2)) y0 = ym; else y1 = ym;
        } while ((i = bottom << 1 | right) === (j = (yp >= ym) << 1 | (xp >= xm)));
        return parent[j] = node, parent[i] = leaf, tree;
    }

    function addAll(data) {
        var d, i, n = data.length,
            x,
            y,
            xz = new Array(n),
            yz = new Array(n),
            x0 = Infinity,
            y0 = Infinity,
            x1 = -Infinity,
            y1 = -Infinity;

        // Compute the points and their extent.
        for (i = 0; i < n; ++i) {
            if (isNaN(x = +this._x.call(null, d = data[i])) || isNaN(y = +this._y.call(null, d))) continue;
            xz[i] = x;
            yz[i] = y;
            if (x < x0) x0 = x;
            if (x > x1) x1 = x;
            if (y < y0) y0 = y;
            if (y > y1) y1 = y;
        }

        // If there were no (valid) points, inherit the existing extent.
        if (x1 < x0) x0 = this._x0, x1 = this._x1;
        if (y1 < y0) y0 = this._y0, y1 = this._y1;

        // Expand the tree to cover the new points.
        this.cover(x0, y0).cover(x1, y1);

        // Add the new points.
        for (i = 0; i < n; ++i) {
            add(this, xz[i], yz[i], data[i]);
        }

        return this;
    }

    function tree_cover(x, y) {
        if (isNaN(x = +x) || isNaN(y = +y)) return this; // ignore invalid points

        var x0 = this._x0,
            y0 = this._y0,
            x1 = this._x1,
            y1 = this._y1;

        // If the quadtree has no extent, initialize them.
        // Integer extent are necessary so that if we later double the extent,
        // the existing quadrant boundaries don’t change due to floating point error!
        if (isNaN(x0)) {
            x1 = (x0 = Math.floor(x)) + 1;
            y1 = (y0 = Math.floor(y)) + 1;
        }

        // Otherwise, double repeatedly to cover.
        else if (x0 > x || x > x1 || y0 > y || y > y1) {
            var z = x1 - x0,
                node = this._root,
                parent,
                i;

            switch (i = (y < (y0 + y1) / 2) << 1 | (x < (x0 + x1) / 2)) {
                case 0: {
                    do parent = new Array(4), parent[i] = node, node = parent;
                    while (z *= 2, x1 = x0 + z, y1 = y0 + z, x > x1 || y > y1);
                    break;
                }
                case 1: {
                    do parent = new Array(4), parent[i] = node, node = parent;
                    while (z *= 2, x0 = x1 - z, y1 = y0 + z, x0 > x || y > y1);
                    break;
                }
                case 2: {
                    do parent = new Array(4), parent[i] = node, node = parent;
                    while (z *= 2, x1 = x0 + z, y0 = y1 - z, x > x1 || y0 > y);
                    break;
                }
                case 3: {
                    do parent = new Array(4), parent[i] = node, node = parent;
                    while (z *= 2, x0 = x1 - z, y0 = y1 - z, x0 > x || y0 > y);
                    break;
                }
            }

            if (this._root && this._root.length) this._root = node;
        }

        // If the quadtree covers the point already, just return.
        else return this;

        this._x0 = x0;
        this._y0 = y0;
        this._x1 = x1;
        this._y1 = y1;
        return this;
    }

    function tree_data() {
        var data = [];
        this.visit(function(node) {
            if (!node.length) do data.push(node.data); while (node = node.next)
        });
        return data;
    }

    function tree_extent(_) {
        return arguments.length
            ? this.cover(+_[0][0], +_[0][1]).cover(+_[1][0], +_[1][1])
            : isNaN(this._x0) ? undefined : [[this._x0, this._y0], [this._x1, this._y1]];
    }

    function Quad(node, x0, y0, x1, y1) {
        this.node = node;
        this.x0 = x0;
        this.y0 = y0;
        this.x1 = x1;
        this.y1 = y1;
    }

    function tree_find(x, y, radius) {
        var data,
            x0 = this._x0,
            y0 = this._y0,
            x1,
            y1,
            x2,
            y2,
            x3 = this._x1,
            y3 = this._y1,
            quads = [],
            node = this._root,
            q,
            i;

        if (node) quads.push(new Quad(node, x0, y0, x3, y3));
        if (radius == null) radius = Infinity;
        else {
            x0 = x - radius, y0 = y - radius;
            x3 = x + radius, y3 = y + radius;
            radius *= radius;
        }

        while (q = quads.pop()) {

            // Stop searching if this quadrant can’t contain a closer node.
            if (!(node = q.node)
                || (x1 = q.x0) > x3
                || (y1 = q.y0) > y3
                || (x2 = q.x1) < x0
                || (y2 = q.y1) < y0) continue;

            // Bisect the current quadrant.
            if (node.length) {
                var xm = (x1 + x2) / 2,
                    ym = (y1 + y2) / 2;

                quads.push(
                    new Quad(node[3], xm, ym, x2, y2),
                    new Quad(node[2], x1, ym, xm, y2),
                    new Quad(node[1], xm, y1, x2, ym),
                    new Quad(node[0], x1, y1, xm, ym)
                );

                // Visit the closest quadrant first.
                if (i = (y >= ym) << 1 | (x >= xm)) {
                    q = quads[quads.length - 1];
                    quads[quads.length - 1] = quads[quads.length - 1 - i];
                    quads[quads.length - 1 - i] = q;
                }
            }

            // Visit this point. (Visiting coincident points isn’t necessary!)
            else {
                var dx = x - +this._x.call(null, node.data),
                    dy = y - +this._y.call(null, node.data),
                    d2 = dx * dx + dy * dy;
                if (d2 < radius) {
                    var d = Math.sqrt(radius = d2);
                    x0 = x - d, y0 = y - d;
                    x3 = x + d, y3 = y + d;
                    data = node.data;
                }
            }
        }

        return data;
    }

    function tree_remove(d) {
        if (isNaN(x = +this._x.call(null, d)) || isNaN(y = +this._y.call(null, d))) return this; // ignore invalid points

        var parent,
            node = this._root,
            retainer,
            previous,
            next,
            x0 = this._x0,
            y0 = this._y0,
            x1 = this._x1,
            y1 = this._y1,
            x,
            y,
            xm,
            ym,
            right,
            bottom,
            i,
            j;

        // If the tree is empty, initialize the root as a leaf.
        if (!node) return this;

        // Find the leaf node for the point.
        // While descending, also retain the deepest parent with a non-removed sibling.
        if (node.length) while (true) {
            if (right = x >= (xm = (x0 + x1) / 2)) x0 = xm; else x1 = xm;
            if (bottom = y >= (ym = (y0 + y1) / 2)) y0 = ym; else y1 = ym;
            if (!(parent = node, node = node[i = bottom << 1 | right])) return this;
            if (!node.length) break;
            if (parent[(i + 1) & 3] || parent[(i + 2) & 3] || parent[(i + 3) & 3]) retainer = parent, j = i;
        }

        // Find the point to remove.
        while (node.data !== d) if (!(previous = node, node = node.next)) return this;
        if (next = node.next) delete node.next;

        // If there are multiple coincident points, remove just the point.
        if (previous) return next ? previous.next = next : delete previous.next, this;

        // If this is the root point, remove it.
        if (!parent) return this._root = next, this;

        // Remove this leaf.
        next ? parent[i] = next : delete parent[i];

        // If the parent now contains exactly one leaf, collapse superfluous parents.
        if ((node = parent[0] || parent[1] || parent[2] || parent[3])
            && node === (parent[3] || parent[2] || parent[1] || parent[0])
            && !node.length) {
            if (retainer) retainer[j] = node;
            else this._root = node;
        }

        return this;
    }

    function removeAll(data) {
        for (var i = 0, n = data.length; i < n; ++i) this.remove(data[i]);
        return this;
    }

    function tree_root() {
        return this._root;
    }

    function tree_size() {
        var size = 0;
        this.visit(function(node) {
            if (!node.length) do ++size; while (node = node.next)
        });
        return size;
    }

    function tree_visit(callback) {
        var quads = [], q, node = this._root, child, x0, y0, x1, y1;
        if (node) quads.push(new Quad(node, this._x0, this._y0, this._x1, this._y1));
        while (q = quads.pop()) {
            if (!callback(node = q.node, x0 = q.x0, y0 = q.y0, x1 = q.x1, y1 = q.y1) && node.length) {
                var xm = (x0 + x1) / 2, ym = (y0 + y1) / 2;
                if (child = node[3]) quads.push(new Quad(child, xm, ym, x1, y1));
                if (child = node[2]) quads.push(new Quad(child, x0, ym, xm, y1));
                if (child = node[1]) quads.push(new Quad(child, xm, y0, x1, ym));
                if (child = node[0]) quads.push(new Quad(child, x0, y0, xm, ym));
            }
        }
        return this;
    }

    function tree_visitAfter(callback) {
        var quads = [], next = [], q;
        if (this._root) quads.push(new Quad(this._root, this._x0, this._y0, this._x1, this._y1));
        while (q = quads.pop()) {
            var node = q.node;
            if (node.length) {
                var child, x0 = q.x0, y0 = q.y0, x1 = q.x1, y1 = q.y1, xm = (x0 + x1) / 2, ym = (y0 + y1) / 2;
                if (child = node[0]) quads.push(new Quad(child, x0, y0, xm, ym));
                if (child = node[1]) quads.push(new Quad(child, xm, y0, x1, ym));
                if (child = node[2]) quads.push(new Quad(child, x0, ym, xm, y1));
                if (child = node[3]) quads.push(new Quad(child, xm, ym, x1, y1));
            }
            next.push(q);
        }
        while (q = next.pop()) {
            callback(q.node, q.x0, q.y0, q.x1, q.y1);
        }
        return this;
    }

    function defaultX(d) {
        return d[0];
    }

    function tree_x(_) {
        return arguments.length ? (this._x = _, this) : this._x;
    }

    function defaultY(d) {
        return d[1];
    }

    function tree_y(_) {
        return arguments.length ? (this._y = _, this) : this._y;
    }

    function quadtree(nodes, x, y) {
        var tree = new Quadtree(x == null ? defaultX : x, y == null ? defaultY : y, NaN, NaN, NaN, NaN);
        return nodes == null ? tree : tree.addAll(nodes);
    }

    function Quadtree(x, y, x0, y0, x1, y1) {
        this._x = x;
        this._y = y;
        this._x0 = x0;
        this._y0 = y0;
        this._x1 = x1;
        this._y1 = y1;
        this._root = undefined;
    }

    function leaf_copy(leaf) {
        var copy = {data: leaf.data}, next = copy;
        while (leaf = leaf.next) next = next.next = {data: leaf.data};
        return copy;
    }

    var treeProto = quadtree.prototype = Quadtree.prototype;

    treeProto.copy = function() {
        var copy = new Quadtree(this._x, this._y, this._x0, this._y0, this._x1, this._y1),
            node = this._root,
            nodes,
            child;

        if (!node) return copy;

        if (!node.length) return copy._root = leaf_copy(node), copy;

        nodes = [{source: node, target: copy._root = new Array(4)}];
        while (node = nodes.pop()) {
            for (var i = 0; i < 4; ++i) {
                if (child = node.source[i]) {
                    if (child.length) nodes.push({source: child, target: node.target[i] = new Array(4)});
                    else node.target[i] = leaf_copy(child);
                }
            }
        }

        return copy;
    };

    treeProto.add = tree_add;
    treeProto.addAll = addAll;
    treeProto.cover = tree_cover;
    treeProto.data = tree_data;
    treeProto.extent = tree_extent;
    treeProto.find = tree_find;
    treeProto.remove = tree_remove;
    treeProto.removeAll = removeAll;
    treeProto.root = tree_root;
    treeProto.size = tree_size;
    treeProto.visit = tree_visit;
    treeProto.visitAfter = tree_visitAfter;
    treeProto.x = tree_x;
    treeProto.y = tree_y;

    function x(d) {
        return d.x + d.vx;
    }

    function y(d) {
        return d.y + d.vy;
    }

    function collide(radius) {
        var nodes,
            radii,
            strength = 1,
            iterations = 1;

        if (typeof radius !== "function") radius = constant$6(radius == null ? 1 : +radius);

        function force() {
            var i, n = nodes.length,
                tree,
                node,
                xi,
                yi,
                ri,
                ri2;

            for (var k = 0; k < iterations; ++k) {
                tree = quadtree(nodes, x, y).visitAfter(prepare);
                for (i = 0; i < n; ++i) {
                    node = nodes[i];
                    ri = radii[node.index], ri2 = ri * ri;
                    xi = node.x + node.vx;
                    yi = node.y + node.vy;
                    tree.visit(apply);
                }
            }

            function apply(quad, x0, y0, x1, y1) {
                var data = quad.data, rj = quad.r, r = ri + rj;
                if (data) {
                    if (data.index > node.index) {
                        var x = xi - data.x - data.vx,
                            y = yi - data.y - data.vy,
                            l = x * x + y * y;
                        if (l < r * r) {
                            if (x === 0) x = jiggle(), l += x * x;
                            if (y === 0) y = jiggle(), l += y * y;
                            l = (r - (l = Math.sqrt(l))) / l * strength;
                            node.vx += (x *= l) * (r = (rj *= rj) / (ri2 + rj));
                            node.vy += (y *= l) * r;
                            data.vx -= x * (r = 1 - r);
                            data.vy -= y * r;
                        }
                    }
                    return;
                }
                return x0 > xi + r || x1 < xi - r || y0 > yi + r || y1 < yi - r;
            }
        }

        function prepare(quad) {
            if (quad.data) return quad.r = radii[quad.data.index];
            for (var i = quad.r = 0; i < 4; ++i) {
                if (quad[i] && quad[i].r > quad.r) {
                    quad.r = quad[i].r;
                }
            }
        }

        function initialize() {
            if (!nodes) return;
            var i, n = nodes.length, node;
            radii = new Array(n);
            for (i = 0; i < n; ++i) node = nodes[i], radii[node.index] = +radius(node, i, nodes);
        }

        force.initialize = function(_) {
            nodes = _;
            initialize();
        };

        force.iterations = function(_) {
            return arguments.length ? (iterations = +_, force) : iterations;
        };

        force.strength = function(_) {
            return arguments.length ? (strength = +_, force) : strength;
        };

        force.radius = function(_) {
            return arguments.length ? (radius = typeof _ === "function" ? _ : constant$6(+_), initialize(), force) : radius;
        };

        return force;
    }

    function index(d) {
        return d.index;
    }

    function find(nodeById, nodeId) {
        var node = nodeById.get(nodeId);
        if (!node) throw new Error("missing: " + nodeId);
        return node;
    }

    function link(links) {
        var id = index,
            strength = defaultStrength,
            strengths,
            distance = constant$6(30),
            distances,
            nodes,
            count,
            bias,
            iterations = 1;

        if (links == null) links = [];

        function defaultStrength(link) {
            return 1 / Math.min(count[link.source.index], count[link.target.index]);
        }

        function force(alpha) {
            for (var k = 0, n = links.length; k < iterations; ++k) {
                for (var i = 0, link, source, target, x, y, l, b; i < n; ++i) {
                    link = links[i], source = link.source, target = link.target;
                    x = target.x + target.vx - source.x - source.vx || jiggle();
                    y = target.y + target.vy - source.y - source.vy || jiggle();
                    l = Math.sqrt(x * x + y * y);
                    l = (l - distances[i]) / l * alpha * strengths[i];
                    x *= l, y *= l;
                    target.vx -= x * (b = bias[i]);
                    target.vy -= y * b;
                    source.vx += x * (b = 1 - b);
                    source.vy += y * b;
                }
            }
        }

        function initialize() {
            if (!nodes) return;

            var i,
                n = nodes.length,
                m = links.length,
                nodeById = map$1(nodes, id),
                link;

            for (i = 0, count = new Array(n); i < m; ++i) {
                link = links[i], link.index = i;
                if (typeof link.source !== "object") link.source = find(nodeById, link.source);
                if (typeof link.target !== "object") link.target = find(nodeById, link.target);
                count[link.source.index] = (count[link.source.index] || 0) + 1;
                count[link.target.index] = (count[link.target.index] || 0) + 1;
            }

            for (i = 0, bias = new Array(m); i < m; ++i) {
                link = links[i], bias[i] = count[link.source.index] / (count[link.source.index] + count[link.target.index]);
            }

            strengths = new Array(m), initializeStrength();
            distances = new Array(m), initializeDistance();
        }

        function initializeStrength() {
            if (!nodes) return;

            for (var i = 0, n = links.length; i < n; ++i) {
                strengths[i] = +strength(links[i], i, links);
            }
        }

        function initializeDistance() {
            if (!nodes) return;

            for (var i = 0, n = links.length; i < n; ++i) {
                distances[i] = +distance(links[i], i, links);
            }
        }

        force.initialize = function(_) {
            nodes = _;
            initialize();
        };

        force.links = function(_) {
            return arguments.length ? (links = _, initialize(), force) : links;
        };

        force.id = function(_) {
            return arguments.length ? (id = _, force) : id;
        };

        force.iterations = function(_) {
            return arguments.length ? (iterations = +_, force) : iterations;
        };

        force.strength = function(_) {
            return arguments.length ? (strength = typeof _ === "function" ? _ : constant$6(+_), initializeStrength(), force) : strength;
        };

        force.distance = function(_) {
            return arguments.length ? (distance = typeof _ === "function" ? _ : constant$6(+_), initializeDistance(), force) : distance;
        };

        return force;
    }

    function x$1(d) {
        return d.x;
    }

    function y$1(d) {
        return d.y;
    }

    var initialRadius = 10;
    var initialAngle = Math.PI * (3 - Math.sqrt(5));

    function simulation(nodes) {
        var simulation,
            alpha = 1,
            alphaMin = 0.001,
            alphaDecay = 1 - Math.pow(alphaMin, 1 / 300),
            alphaTarget = 0,
            velocityDecay = 0.6,
            forces = map$1(),
            stepper = timer(step),
            event = dispatch("tick", "end");

        if (nodes == null) nodes = [];

        function step() {
            tick();
            event.call("tick", simulation);
            if (alpha < alphaMin) {
                stepper.stop();
                event.call("end", simulation);
            }
        }

        function tick() {
            var i, n = nodes.length, node;

            alpha += (alphaTarget - alpha) * alphaDecay;

            forces.each(function(force) {
                force(alpha);
            });

            for (i = 0; i < n; ++i) {
                node = nodes[i];
                if (node.fx == null) node.x += node.vx *= velocityDecay;
                else node.x = node.fx, node.vx = 0;
                if (node.fy == null) node.y += node.vy *= velocityDecay;
                else node.y = node.fy, node.vy = 0;
            }
        }

        function initializeNodes() {
            for (var i = 0, n = nodes.length, node; i < n; ++i) {
                node = nodes[i], node.index = i;
                if (isNaN(node.x) || isNaN(node.y)) {
                    var radius = initialRadius * Math.sqrt(i), angle = i * initialAngle;
                    node.x = radius * Math.cos(angle);
                    node.y = radius * Math.sin(angle);
                }
                if (isNaN(node.vx) || isNaN(node.vy)) {
                    node.vx = node.vy = 0;
                }
            }
        }

        function initializeForce(force) {
            if (force.initialize) force.initialize(nodes);
            return force;
        }

        initializeNodes();

        return simulation = {
            tick: tick,

            restart: function() {
                return stepper.restart(step), simulation;
            },

            stop: function() {
                return stepper.stop(), simulation;
            },

            nodes: function(_) {
                return arguments.length ? (nodes = _, initializeNodes(), forces.each(initializeForce), simulation) : nodes;
            },

            alpha: function(_) {
                return arguments.length ? (alpha = +_, simulation) : alpha;
            },

            alphaMin: function(_) {
                return arguments.length ? (alphaMin = +_, simulation) : alphaMin;
            },

            alphaDecay: function(_) {
                return arguments.length ? (alphaDecay = +_, simulation) : +alphaDecay;
            },

            alphaTarget: function(_) {
                return arguments.length ? (alphaTarget = +_, simulation) : alphaTarget;
            },

            velocityDecay: function(_) {
                return arguments.length ? (velocityDecay = 1 - _, simulation) : 1 - velocityDecay;
            },

            force: function(name, _) {
                return arguments.length > 1 ? (_ == null ? forces.remove(name) : forces.set(name, initializeForce(_)), simulation) : forces.get(name);
            },

            find: function(x, y, radius) {
                var i = 0,
                    n = nodes.length,
                    dx,
                    dy,
                    d2,
                    node,
                    closest;

                if (radius == null) radius = Infinity;
                else radius *= radius;

                for (i = 0; i < n; ++i) {
                    node = nodes[i];
                    dx = x - node.x;
                    dy = y - node.y;
                    d2 = dx * dx + dy * dy;
                    if (d2 < radius) closest = node, radius = d2;
                }

                return closest;
            },

            on: function(name, _) {
                return arguments.length > 1 ? (event.on(name, _), simulation) : event.on(name);
            }
        };
    }

    function manyBody() {
        var nodes,
            node,
            alpha,
            strength = constant$6(-30),
            strengths,
            distanceMin2 = 1,
            distanceMax2 = Infinity,
            theta2 = 0.81;

        function force(_) {
            var i, n = nodes.length, tree = quadtree(nodes, x$1, y$1).visitAfter(accumulate);
            for (alpha = _, i = 0; i < n; ++i) node = nodes[i], tree.visit(apply);
        }

        function initialize() {
            if (!nodes) return;
            var i, n = nodes.length, node;
            strengths = new Array(n);
            for (i = 0; i < n; ++i) node = nodes[i], strengths[node.index] = +strength(node, i, nodes);
        }

        function accumulate(quad) {
            var strength = 0, q, c, weight = 0, x, y, i;

            // For internal nodes, accumulate forces from child quadrants.
            if (quad.length) {
                for (x = y = i = 0; i < 4; ++i) {
                    if ((q = quad[i]) && (c = Math.abs(q.value))) {
                        strength += q.value, weight += c, x += c * q.x, y += c * q.y;
                    }
                }
                quad.x = x / weight;
                quad.y = y / weight;
            }

            // For leaf nodes, accumulate forces from coincident quadrants.
            else {
                q = quad;
                q.x = q.data.x;
                q.y = q.data.y;
                do strength += strengths[q.data.index];
                while (q = q.next);
            }

            quad.value = strength;
        }

        function apply(quad, x1, _, x2) {
            if (!quad.value) return true;

            var x = quad.x - node.x,
                y = quad.y - node.y,
                w = x2 - x1,
                l = x * x + y * y;

            // Apply the Barnes-Hut approximation if possible.
            // Limit forces for very close nodes; randomize direction if coincident.
            if (w * w / theta2 < l) {
                if (l < distanceMax2) {
                    if (x === 0) x = jiggle(), l += x * x;
                    if (y === 0) y = jiggle(), l += y * y;
                    if (l < distanceMin2) l = Math.sqrt(distanceMin2 * l);
                    node.vx += x * quad.value * alpha / l;
                    node.vy += y * quad.value * alpha / l;
                }
                return true;
            }

            // Otherwise, process points directly.
            else if (quad.length || l >= distanceMax2) return;

            // Limit forces for very close nodes; randomize direction if coincident.
            if (quad.data !== node || quad.next) {
                if (x === 0) x = jiggle(), l += x * x;
                if (y === 0) y = jiggle(), l += y * y;
                if (l < distanceMin2) l = Math.sqrt(distanceMin2 * l);
            }

            do if (quad.data !== node) {
                w = strengths[quad.data.index] * alpha / l;
                node.vx += x * w;
                node.vy += y * w;
            } while (quad = quad.next);
        }

        force.initialize = function(_) {
            nodes = _;
            initialize();
        };

        force.strength = function(_) {
            return arguments.length ? (strength = typeof _ === "function" ? _ : constant$6(+_), initialize(), force) : strength;
        };

        force.distanceMin = function(_) {
            return arguments.length ? (distanceMin2 = _ * _, force) : Math.sqrt(distanceMin2);
        };

        force.distanceMax = function(_) {
            return arguments.length ? (distanceMax2 = _ * _, force) : Math.sqrt(distanceMax2);
        };

        force.theta = function(_) {
            return arguments.length ? (theta2 = _ * _, force) : Math.sqrt(theta2);
        };

        return force;
    }

    function radial(radius, x, y) {
        var nodes,
            strength = constant$6(0.1),
            strengths,
            radiuses;

        if (typeof radius !== "function") radius = constant$6(+radius);
        if (x == null) x = 0;
        if (y == null) y = 0;

        function force(alpha) {
            for (var i = 0, n = nodes.length; i < n; ++i) {
                var node = nodes[i],
                    dx = node.x - x || 1e-6,
                    dy = node.y - y || 1e-6,
                    r = Math.sqrt(dx * dx + dy * dy),
                    k = (radiuses[i] - r) * strengths[i] * alpha / r;
                node.vx += dx * k;
                node.vy += dy * k;
            }
        }

        function initialize() {
            if (!nodes) return;
            var i, n = nodes.length;
            strengths = new Array(n);
            radiuses = new Array(n);
            for (i = 0; i < n; ++i) {
                radiuses[i] = +radius(nodes[i], i, nodes);
                strengths[i] = isNaN(radiuses[i]) ? 0 : +strength(nodes[i], i, nodes);
            }
        }

        force.initialize = function(_) {
            nodes = _, initialize();
        };

        force.strength = function(_) {
            return arguments.length ? (strength = typeof _ === "function" ? _ : constant$6(+_), initialize(), force) : strength;
        };

        force.radius = function(_) {
            return arguments.length ? (radius = typeof _ === "function" ? _ : constant$6(+_), initialize(), force) : radius;
        };

        force.x = function(_) {
            return arguments.length ? (x = +_, force) : x;
        };

        force.y = function(_) {
            return arguments.length ? (y = +_, force) : y;
        };

        return force;
    }

    function x$2(x) {
        var strength = constant$6(0.1),
            nodes,
            strengths,
            xz;

        if (typeof x !== "function") x = constant$6(x == null ? 0 : +x);

        function force(alpha) {
            for (var i = 0, n = nodes.length, node; i < n; ++i) {
                node = nodes[i], node.vx += (xz[i] - node.x) * strengths[i] * alpha;
            }
        }

        function initialize() {
            if (!nodes) return;
            var i, n = nodes.length;
            strengths = new Array(n);
            xz = new Array(n);
            for (i = 0; i < n; ++i) {
                strengths[i] = isNaN(xz[i] = +x(nodes[i], i, nodes)) ? 0 : +strength(nodes[i], i, nodes);
            }
        }

        force.initialize = function(_) {
            nodes = _;
            initialize();
        };

        force.strength = function(_) {
            return arguments.length ? (strength = typeof _ === "function" ? _ : constant$6(+_), initialize(), force) : strength;
        };

        force.x = function(_) {
            return arguments.length ? (x = typeof _ === "function" ? _ : constant$6(+_), initialize(), force) : x;
        };

        return force;
    }

    function y$2(y) {
        var strength = constant$6(0.1),
            nodes,
            strengths,
            yz;

        if (typeof y !== "function") y = constant$6(y == null ? 0 : +y);

        function force(alpha) {
            for (var i = 0, n = nodes.length, node; i < n; ++i) {
                node = nodes[i], node.vy += (yz[i] - node.y) * strengths[i] * alpha;
            }
        }

        function initialize() {
            if (!nodes) return;
            var i, n = nodes.length;
            strengths = new Array(n);
            yz = new Array(n);
            for (i = 0; i < n; ++i) {
                strengths[i] = isNaN(yz[i] = +y(nodes[i], i, nodes)) ? 0 : +strength(nodes[i], i, nodes);
            }
        }

        force.initialize = function(_) {
            nodes = _;
            initialize();
        };

        force.strength = function(_) {
            return arguments.length ? (strength = typeof _ === "function" ? _ : constant$6(+_), initialize(), force) : strength;
        };

        force.y = function(_) {
            return arguments.length ? (y = typeof _ === "function" ? _ : constant$6(+_), initialize(), force) : y;
        };

        return force;
    }

// Computes the decimal coefficient and exponent of the specified number x with
// significant digits p, where x is positive and p is in [1, 21] or undefined.
// For example, formatDecimal(1.23) returns ["123", 0].
    function formatDecimal(x, p) {
        if ((i = (x = p ? x.toExponential(p - 1) : x.toExponential()).indexOf("e")) < 0) return null; // NaN, ±Infinity
        var i, coefficient = x.slice(0, i);

        // The string returned by toExponential either has the form \d\.\d+e[-+]\d+
        // (e.g., 1.2e+3) or the form \de[-+]\d+ (e.g., 1e+3).
        return [
            coefficient.length > 1 ? coefficient[0] + coefficient.slice(2) : coefficient,
            +x.slice(i + 1)
        ];
    }

    function exponent$1(x) {
        return x = formatDecimal(Math.abs(x)), x ? x[1] : NaN;
    }

    function formatGroup(grouping, thousands) {
        return function(value, width) {
            var i = value.length,
                t = [],
                j = 0,
                g = grouping[0],
                length = 0;

            while (i > 0 && g > 0) {
                if (length + g + 1 > width) g = Math.max(1, width - length);
                t.push(value.substring(i -= g, i + g));
                if ((length += g + 1) > width) break;
                g = grouping[j = (j + 1) % grouping.length];
            }

            return t.reverse().join(thousands);
        };
    }

    function formatNumerals(numerals) {
        return function(value) {
            return value.replace(/[0-9]/g, function(i) {
                return numerals[+i];
            });
        };
    }

    function formatDefault(x, p) {
        x = x.toPrecision(p);

        out: for (var n = x.length, i = 1, i0 = -1, i1; i < n; ++i) {
            switch (x[i]) {
                case ".": i0 = i1 = i; break;
                case "0": if (i0 === 0) i0 = i; i1 = i; break;
                case "e": break out;
                default: if (i0 > 0) i0 = 0; break;
            }
        }

        return i0 > 0 ? x.slice(0, i0) + x.slice(i1 + 1) : x;
    }

    var prefixExponent;

    function formatPrefixAuto(x, p) {
        var d = formatDecimal(x, p);
        if (!d) return x + "";
        var coefficient = d[0],
            exponent = d[1],
            i = exponent - (prefixExponent = Math.max(-8, Math.min(8, Math.floor(exponent / 3))) * 3) + 1,
            n = coefficient.length;
        return i === n ? coefficient
            : i > n ? coefficient + new Array(i - n + 1).join("0")
                : i > 0 ? coefficient.slice(0, i) + "." + coefficient.slice(i)
                    : "0." + new Array(1 - i).join("0") + formatDecimal(x, Math.max(0, p + i - 1))[0]; // less than 1y!
    }

    function formatRounded(x, p) {
        var d = formatDecimal(x, p);
        if (!d) return x + "";
        var coefficient = d[0],
            exponent = d[1];
        return exponent < 0 ? "0." + new Array(-exponent).join("0") + coefficient
            : coefficient.length > exponent + 1 ? coefficient.slice(0, exponent + 1) + "." + coefficient.slice(exponent + 1)
                : coefficient + new Array(exponent - coefficient.length + 2).join("0");
    }

    var formatTypes = {
        "": formatDefault,
        "%": function(x, p) { return (x * 100).toFixed(p); },
        "b": function(x) { return Math.round(x).toString(2); },
        "c": function(x) { return x + ""; },
        "d": function(x) { return Math.round(x).toString(10); },
        "e": function(x, p) { return x.toExponential(p); },
        "f": function(x, p) { return x.toFixed(p); },
        "g": function(x, p) { return x.toPrecision(p); },
        "o": function(x) { return Math.round(x).toString(8); },
        "p": function(x, p) { return formatRounded(x * 100, p); },
        "r": formatRounded,
        "s": formatPrefixAuto,
        "X": function(x) { return Math.round(x).toString(16).toUpperCase(); },
        "x": function(x) { return Math.round(x).toString(16); }
    };

// [[fill]align][sign][symbol][0][width][,][.precision][type]
    var re = /^(?:(.)?([<>=^]))?([+\-\( ])?([$#])?(0)?(\d+)?(,)?(\.\d+)?([a-z%])?$/i;

    function formatSpecifier(specifier) {
        return new FormatSpecifier(specifier);
    }

    formatSpecifier.prototype = FormatSpecifier.prototype; // instanceof

    function FormatSpecifier(specifier) {
        if (!(match = re.exec(specifier))) throw new Error("invalid format: " + specifier);

        var match,
            fill = match[1] || " ",
            align = match[2] || ">",
            sign = match[3] || "-",
            symbol = match[4] || "",
            zero = !!match[5],
            width = match[6] && +match[6],
            comma = !!match[7],
            precision = match[8] && +match[8].slice(1),
            type = match[9] || "";

        // The "n" type is an alias for ",g".
        if (type === "n") comma = true, type = "g";

        // Map invalid types to the default format.
        else if (!formatTypes[type]) type = "";

        // If zero fill is specified, padding goes after sign and before digits.
        if (zero || (fill === "0" && align === "=")) zero = true, fill = "0", align = "=";

        this.fill = fill;
        this.align = align;
        this.sign = sign;
        this.symbol = symbol;
        this.zero = zero;
        this.width = width;
        this.comma = comma;
        this.precision = precision;
        this.type = type;
    }

    FormatSpecifier.prototype.toString = function() {
        return this.fill
            + this.align
            + this.sign
            + this.symbol
            + (this.zero ? "0" : "")
            + (this.width == null ? "" : Math.max(1, this.width | 0))
            + (this.comma ? "," : "")
            + (this.precision == null ? "" : "." + Math.max(0, this.precision | 0))
            + this.type;
    };

    function identity$3(x) {
        return x;
    }

    var prefixes = ["y","z","a","f","p","n","\xB5","m","","k","M","G","T","P","E","Z","Y"];

    function formatLocale(locale) {
        var group = locale.grouping && locale.thousands ? formatGroup(locale.grouping, locale.thousands) : identity$3,
            currency = locale.currency,
            decimal = locale.decimal,
            numerals = locale.numerals ? formatNumerals(locale.numerals) : identity$3,
            percent = locale.percent || "%";

        function newFormat(specifier) {
            specifier = formatSpecifier(specifier);

            var fill = specifier.fill,
                align = specifier.align,
                sign = specifier.sign,
                symbol = specifier.symbol,
                zero = specifier.zero,
                width = specifier.width,
                comma = specifier.comma,
                precision = specifier.precision,
                type = specifier.type;

            // Compute the prefix and suffix.
            // For SI-prefix, the suffix is lazily computed.
            var prefix = symbol === "$" ? currency[0] : symbol === "#" && /[boxX]/.test(type) ? "0" + type.toLowerCase() : "",
                suffix = symbol === "$" ? currency[1] : /[%p]/.test(type) ? percent : "";

            // What format function should we use?
            // Is this an integer type?
            // Can this type generate exponential notation?
            var formatType = formatTypes[type],
                maybeSuffix = !type || /[defgprs%]/.test(type);

            // Set the default precision if not specified,
            // or clamp the specified precision to the supported range.
            // For significant precision, it must be in [1, 21].
            // For fixed precision, it must be in [0, 20].
            precision = precision == null ? (type ? 6 : 12)
                : /[gprs]/.test(type) ? Math.max(1, Math.min(21, precision))
                    : Math.max(0, Math.min(20, precision));

            function format(value) {
                var valuePrefix = prefix,
                    valueSuffix = suffix,
                    i, n, c;

                if (type === "c") {
                    valueSuffix = formatType(value) + valueSuffix;
                    value = "";
                } else {
                    value = +value;

                    // Perform the initial formatting.
                    var valueNegative = value < 0;
                    value = formatType(Math.abs(value), precision);

                    // If a negative value rounds to zero during formatting, treat as positive.
                    if (valueNegative && +value === 0) valueNegative = false;

                    // Compute the prefix and suffix.
                    valuePrefix = (valueNegative ? (sign === "(" ? sign : "-") : sign === "-" || sign === "(" ? "" : sign) + valuePrefix;
                    valueSuffix = (type === "s" ? prefixes[8 + prefixExponent / 3] : "") + valueSuffix + (valueNegative && sign === "(" ? ")" : "");

                    // Break the formatted value into the integer “value” part that can be
                    // grouped, and fractional or exponential “suffix” part that is not.
                    if (maybeSuffix) {
                        i = -1, n = value.length;
                        while (++i < n) {
                            if (c = value.charCodeAt(i), 48 > c || c > 57) {
                                valueSuffix = (c === 46 ? decimal + value.slice(i + 1) : value.slice(i)) + valueSuffix;
                                value = value.slice(0, i);
                                break;
                            }
                        }
                    }
                }

                // If the fill character is not "0", grouping is applied before padding.
                if (comma && !zero) value = group(value, Infinity);

                // Compute the padding.
                var length = valuePrefix.length + value.length + valueSuffix.length,
                    padding = length < width ? new Array(width - length + 1).join(fill) : "";

                // If the fill character is "0", grouping is applied after padding.
                if (comma && zero) value = group(padding + value, padding.length ? width - valueSuffix.length : Infinity), padding = "";

                // Reconstruct the final output based on the desired alignment.
                switch (align) {
                    case "<": value = valuePrefix + value + valueSuffix + padding; break;
                    case "=": value = valuePrefix + padding + value + valueSuffix; break;
                    case "^": value = padding.slice(0, length = padding.length >> 1) + valuePrefix + value + valueSuffix + padding.slice(length); break;
                    default: value = padding + valuePrefix + value + valueSuffix; break;
                }

                return numerals(value);
            }

            format.toString = function() {
                return specifier + "";
            };

            return format;
        }

        function formatPrefix(specifier, value) {
            var f = newFormat((specifier = formatSpecifier(specifier), specifier.type = "f", specifier)),
                e = Math.max(-8, Math.min(8, Math.floor(exponent$1(value) / 3))) * 3,
                k = Math.pow(10, -e),
                prefix = prefixes[8 + e / 3];
            return function(value) {
                return f(k * value) + prefix;
            };
        }

        return {
            format: newFormat,
            formatPrefix: formatPrefix
        };
    }

    var locale;



    defaultLocale({
        decimal: ".",
        thousands: ",",
        grouping: [3],
        currency: ["$", ""]
    });

    function defaultLocale(definition) {
        locale = formatLocale(definition);
        exports.format = locale.format;
        exports.formatPrefix = locale.formatPrefix;
        return locale;
    }

    function precisionFixed(step) {
        return Math.max(0, -exponent$1(Math.abs(step)));
    }

    function precisionPrefix(step, value) {
        return Math.max(0, Math.max(-8, Math.min(8, Math.floor(exponent$1(value) / 3))) * 3 - exponent$1(Math.abs(step)));
    }

    function precisionRound(step, max) {
        step = Math.abs(step), max = Math.abs(max) - step;
        return Math.max(0, exponent$1(max) - exponent$1(step)) + 1;
    }

// Adds floating point numbers with twice the normal precision.
// Reference: J. R. Shewchuk, Adaptive Precision Floating-Point Arithmetic and
// Fast Robust Geometric Predicates, Discrete & Computational Geometry 18(3)
// 305–363 (1997).
// Code adapted from GeographicLib by Charles F. F. Karney,
// http://geographiclib.sourceforge.net/

    function adder() {
        return new Adder;
    }

    function Adder() {
        this.reset();
    }

    Adder.prototype = {
        constructor: Adder,
        reset: function() {
            this.s = // rounded value
                this.t = 0; // exact error
        },
        add: function(y) {
            add$1(temp, y, this.t);
            add$1(this, temp.s, this.s);
            if (this.s) this.t += temp.t;
            else this.s = temp.t;
        },
        valueOf: function() {
            return this.s;
        }
    };

    var temp = new Adder;

    function add$1(adder, a, b) {
        var x = adder.s = a + b,
            bv = x - a,
            av = x - bv;
        adder.t = (a - av) + (b - bv);
    }

    var epsilon$2 = 1e-6;
    var epsilon2$1 = 1e-12;
    var pi$3 = Math.PI;
    var halfPi$2 = pi$3 / 2;
    var quarterPi = pi$3 / 4;
    var tau$3 = pi$3 * 2;

    var degrees$1 = 180 / pi$3;
    var radians = pi$3 / 180;

    var abs = Math.abs;
    var atan = Math.atan;
    var atan2 = Math.atan2;
    var cos$1 = Math.cos;
    var ceil = Math.ceil;
    var exp = Math.exp;

    var log = Math.log;
    var pow = Math.pow;
    var sin$1 = Math.sin;
    var sign = Math.sign || function(x) { return x > 0 ? 1 : x < 0 ? -1 : 0; };
    var sqrt = Math.sqrt;
    var tan = Math.tan;

    function acos(x) {
        return x > 1 ? 0 : x < -1 ? pi$3 : Math.acos(x);
    }

    function asin(x) {
        return x > 1 ? halfPi$2 : x < -1 ? -halfPi$2 : Math.asin(x);
    }

    function haversin(x) {
        return (x = sin$1(x / 2)) * x;
    }

    function noop$1() {}

    function streamGeometry(geometry, stream) {
        if (geometry && streamGeometryType.hasOwnProperty(geometry.type)) {
            streamGeometryType[geometry.type](geometry, stream);
        }
    }

    var streamObjectType = {
        Feature: function(object, stream) {
            streamGeometry(object.geometry, stream);
        },
        FeatureCollection: function(object, stream) {
            var features = object.features, i = -1, n = features.length;
            while (++i < n) streamGeometry(features[i].geometry, stream);
        }
    };

    var streamGeometryType = {
        Sphere: function(object, stream) {
            stream.sphere();
        },
        Point: function(object, stream) {
            object = object.coordinates;
            stream.point(object[0], object[1], object[2]);
        },
        MultiPoint: function(object, stream) {
            var coordinates = object.coordinates, i = -1, n = coordinates.length;
            while (++i < n) object = coordinates[i], stream.point(object[0], object[1], object[2]);
        },
        LineString: function(object, stream) {
            streamLine(object.coordinates, stream, 0);
        },
        MultiLineString: function(object, stream) {
            var coordinates = object.coordinates, i = -1, n = coordinates.length;
            while (++i < n) streamLine(coordinates[i], stream, 0);
        },
        Polygon: function(object, stream) {
            streamPolygon(object.coordinates, stream);
        },
        MultiPolygon: function(object, stream) {
            var coordinates = object.coordinates, i = -1, n = coordinates.length;
            while (++i < n) streamPolygon(coordinates[i], stream);
        },
        GeometryCollection: function(object, stream) {
            var geometries = object.geometries, i = -1, n = geometries.length;
            while (++i < n) streamGeometry(geometries[i], stream);
        }
    };

    function streamLine(coordinates, stream, closed) {
        var i = -1, n = coordinates.length - closed, coordinate;
        stream.lineStart();
        while (++i < n) coordinate = coordinates[i], stream.point(coordinate[0], coordinate[1], coordinate[2]);
        stream.lineEnd();
    }

    function streamPolygon(coordinates, stream) {
        var i = -1, n = coordinates.length;
        stream.polygonStart();
        while (++i < n) streamLine(coordinates[i], stream, 1);
        stream.polygonEnd();
    }

    function geoStream(object, stream) {
        if (object && streamObjectType.hasOwnProperty(object.type)) {
            streamObjectType[object.type](object, stream);
        } else {
            streamGeometry(object, stream);
        }
    }

    var areaRingSum = adder();

    var areaSum = adder();
    var lambda00;
    var phi00;
    var lambda0;
    var cosPhi0;
    var sinPhi0;

    var areaStream = {
        point: noop$1,
        lineStart: noop$1,
        lineEnd: noop$1,
        polygonStart: function() {
            areaRingSum.reset();
            areaStream.lineStart = areaRingStart;
            areaStream.lineEnd = areaRingEnd;
        },
        polygonEnd: function() {
            var areaRing = +areaRingSum;
            areaSum.add(areaRing < 0 ? tau$3 + areaRing : areaRing);
            this.lineStart = this.lineEnd = this.point = noop$1;
        },
        sphere: function() {
            areaSum.add(tau$3);
        }
    };

    function areaRingStart() {
        areaStream.point = areaPointFirst;
    }

    function areaRingEnd() {
        areaPoint(lambda00, phi00);
    }

    function areaPointFirst(lambda, phi) {
        areaStream.point = areaPoint;
        lambda00 = lambda, phi00 = phi;
        lambda *= radians, phi *= radians;
        lambda0 = lambda, cosPhi0 = cos$1(phi = phi / 2 + quarterPi), sinPhi0 = sin$1(phi);
    }

    function areaPoint(lambda, phi) {
        lambda *= radians, phi *= radians;
        phi = phi / 2 + quarterPi; // half the angular distance from south pole

        // Spherical excess E for a spherical triangle with vertices: south pole,
        // previous point, current point.  Uses a formula derived from Cagnoli’s
        // theorem.  See Todhunter, Spherical Trig. (1871), Sec. 103, Eq. (2).
        var dLambda = lambda - lambda0,
            sdLambda = dLambda >= 0 ? 1 : -1,
            adLambda = sdLambda * dLambda,
            cosPhi = cos$1(phi),
            sinPhi = sin$1(phi),
            k = sinPhi0 * sinPhi,
            u = cosPhi0 * cosPhi + k * cos$1(adLambda),
            v = k * sdLambda * sin$1(adLambda);
        areaRingSum.add(atan2(v, u));

        // Advance the previous points.
        lambda0 = lambda, cosPhi0 = cosPhi, sinPhi0 = sinPhi;
    }

    function area(object) {
        areaSum.reset();
        geoStream(object, areaStream);
        return areaSum * 2;
    }

    function spherical(cartesian) {
        return [atan2(cartesian[1], cartesian[0]), asin(cartesian[2])];
    }

    function cartesian(spherical) {
        var lambda = spherical[0], phi = spherical[1], cosPhi = cos$1(phi);
        return [cosPhi * cos$1(lambda), cosPhi * sin$1(lambda), sin$1(phi)];
    }

    function cartesianDot(a, b) {
        return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
    }

    function cartesianCross(a, b) {
        return [a[1] * b[2] - a[2] * b[1], a[2] * b[0] - a[0] * b[2], a[0] * b[1] - a[1] * b[0]];
    }

// TODO return a
    function cartesianAddInPlace(a, b) {
        a[0] += b[0], a[1] += b[1], a[2] += b[2];
    }

    function cartesianScale(vector, k) {
        return [vector[0] * k, vector[1] * k, vector[2] * k];
    }

// TODO return d
    function cartesianNormalizeInPlace(d) {
        var l = sqrt(d[0] * d[0] + d[1] * d[1] + d[2] * d[2]);
        d[0] /= l, d[1] /= l, d[2] /= l;
    }

    var lambda0$1;
    var phi0;
    var lambda1;
    var phi1;
    var lambda2;
    var lambda00$1;
    var phi00$1;
    var p0;
    var deltaSum = adder();
    var ranges;
    var range;

    var boundsStream = {
        point: boundsPoint,
        lineStart: boundsLineStart,
        lineEnd: boundsLineEnd,
        polygonStart: function() {
            boundsStream.point = boundsRingPoint;
            boundsStream.lineStart = boundsRingStart;
            boundsStream.lineEnd = boundsRingEnd;
            deltaSum.reset();
            areaStream.polygonStart();
        },
        polygonEnd: function() {
            areaStream.polygonEnd();
            boundsStream.point = boundsPoint;
            boundsStream.lineStart = boundsLineStart;
            boundsStream.lineEnd = boundsLineEnd;
            if (areaRingSum < 0) lambda0$1 = -(lambda1 = 180), phi0 = -(phi1 = 90);
            else if (deltaSum > epsilon$2) phi1 = 90;
            else if (deltaSum < -epsilon$2) phi0 = -90;
            range[0] = lambda0$1, range[1] = lambda1;
        }
    };

    function boundsPoint(lambda, phi) {
        ranges.push(range = [lambda0$1 = lambda, lambda1 = lambda]);
        if (phi < phi0) phi0 = phi;
        if (phi > phi1) phi1 = phi;
    }

    function linePoint(lambda, phi) {
        var p = cartesian([lambda * radians, phi * radians]);
        if (p0) {
            var normal = cartesianCross(p0, p),
                equatorial = [normal[1], -normal[0], 0],
                inflection = cartesianCross(equatorial, normal);
            cartesianNormalizeInPlace(inflection);
            inflection = spherical(inflection);
            var delta = lambda - lambda2,
                sign$$1 = delta > 0 ? 1 : -1,
                lambdai = inflection[0] * degrees$1 * sign$$1,
                phii,
                antimeridian = abs(delta) > 180;
            if (antimeridian ^ (sign$$1 * lambda2 < lambdai && lambdai < sign$$1 * lambda)) {
                phii = inflection[1] * degrees$1;
                if (phii > phi1) phi1 = phii;
            } else if (lambdai = (lambdai + 360) % 360 - 180, antimeridian ^ (sign$$1 * lambda2 < lambdai && lambdai < sign$$1 * lambda)) {
                phii = -inflection[1] * degrees$1;
                if (phii < phi0) phi0 = phii;
            } else {
                if (phi < phi0) phi0 = phi;
                if (phi > phi1) phi1 = phi;
            }
            if (antimeridian) {
                if (lambda < lambda2) {
                    if (angle(lambda0$1, lambda) > angle(lambda0$1, lambda1)) lambda1 = lambda;
                } else {
                    if (angle(lambda, lambda1) > angle(lambda0$1, lambda1)) lambda0$1 = lambda;
                }
            } else {
                if (lambda1 >= lambda0$1) {
                    if (lambda < lambda0$1) lambda0$1 = lambda;
                    if (lambda > lambda1) lambda1 = lambda;
                } else {
                    if (lambda > lambda2) {
                        if (angle(lambda0$1, lambda) > angle(lambda0$1, lambda1)) lambda1 = lambda;
                    } else {
                        if (angle(lambda, lambda1) > angle(lambda0$1, lambda1)) lambda0$1 = lambda;
                    }
                }
            }
        } else {
            ranges.push(range = [lambda0$1 = lambda, lambda1 = lambda]);
        }
        if (phi < phi0) phi0 = phi;
        if (phi > phi1) phi1 = phi;
        p0 = p, lambda2 = lambda;
    }

    function boundsLineStart() {
        boundsStream.point = linePoint;
    }

    function boundsLineEnd() {
        range[0] = lambda0$1, range[1] = lambda1;
        boundsStream.point = boundsPoint;
        p0 = null;
    }

    function boundsRingPoint(lambda, phi) {
        if (p0) {
            var delta = lambda - lambda2;
            deltaSum.add(abs(delta) > 180 ? delta + (delta > 0 ? 360 : -360) : delta);
        } else {
            lambda00$1 = lambda, phi00$1 = phi;
        }
        areaStream.point(lambda, phi);
        linePoint(lambda, phi);
    }

    function boundsRingStart() {
        areaStream.lineStart();
    }

    function boundsRingEnd() {
        boundsRingPoint(lambda00$1, phi00$1);
        areaStream.lineEnd();
        if (abs(deltaSum) > epsilon$2) lambda0$1 = -(lambda1 = 180);
        range[0] = lambda0$1, range[1] = lambda1;
        p0 = null;
    }

// Finds the left-right distance between two longitudes.
// This is almost the same as (lambda1 - lambda0 + 360°) % 360°, except that we want
// the distance between ±180° to be 360°.
    function angle(lambda0, lambda1) {
        return (lambda1 -= lambda0) < 0 ? lambda1 + 360 : lambda1;
    }

    function rangeCompare(a, b) {
        return a[0] - b[0];
    }

    function rangeContains(range, x) {
        return range[0] <= range[1] ? range[0] <= x && x <= range[1] : x < range[0] || range[1] < x;
    }

    function bounds(feature) {
        var i, n, a, b, merged, deltaMax, delta;

        phi1 = lambda1 = -(lambda0$1 = phi0 = Infinity);
        ranges = [];
        geoStream(feature, boundsStream);

        // First, sort ranges by their minimum longitudes.
        if (n = ranges.length) {
            ranges.sort(rangeCompare);

            // Then, merge any ranges that overlap.
            for (i = 1, a = ranges[0], merged = [a]; i < n; ++i) {
                b = ranges[i];
                if (rangeContains(a, b[0]) || rangeContains(a, b[1])) {
                    if (angle(a[0], b[1]) > angle(a[0], a[1])) a[1] = b[1];
                    if (angle(b[0], a[1]) > angle(a[0], a[1])) a[0] = b[0];
                } else {
                    merged.push(a = b);
                }
            }

            // Finally, find the largest gap between the merged ranges.
            // The final bounding box will be the inverse of this gap.
            for (deltaMax = -Infinity, n = merged.length - 1, i = 0, a = merged[n]; i <= n; a = b, ++i) {
                b = merged[i];
                if ((delta = angle(a[1], b[0])) > deltaMax) deltaMax = delta, lambda0$1 = b[0], lambda1 = a[1];
            }
        }

        ranges = range = null;

        return lambda0$1 === Infinity || phi0 === Infinity
            ? [[NaN, NaN], [NaN, NaN]]
            : [[lambda0$1, phi0], [lambda1, phi1]];
    }

    var W0;
    var W1;
    var X0;
    var Y0;
    var Z0;
    var X1;
    var Y1;
    var Z1;
    var X2;
    var Y2;
    var Z2;
    var lambda00$2;
    var phi00$2;
    var x0;
    var y0;
    var z0; // previous point

    var centroidStream = {
        sphere: noop$1,
        point: centroidPoint,
        lineStart: centroidLineStart,
        lineEnd: centroidLineEnd,
        polygonStart: function() {
            centroidStream.lineStart = centroidRingStart;
            centroidStream.lineEnd = centroidRingEnd;
        },
        polygonEnd: function() {
            centroidStream.lineStart = centroidLineStart;
            centroidStream.lineEnd = centroidLineEnd;
        }
    };

// Arithmetic mean of Cartesian vectors.
    function centroidPoint(lambda, phi) {
        lambda *= radians, phi *= radians;
        var cosPhi = cos$1(phi);
        centroidPointCartesian(cosPhi * cos$1(lambda), cosPhi * sin$1(lambda), sin$1(phi));
    }

    function centroidPointCartesian(x, y, z) {
        ++W0;
        X0 += (x - X0) / W0;
        Y0 += (y - Y0) / W0;
        Z0 += (z - Z0) / W0;
    }

    function centroidLineStart() {
        centroidStream.point = centroidLinePointFirst;
    }

    function centroidLinePointFirst(lambda, phi) {
        lambda *= radians, phi *= radians;
        var cosPhi = cos$1(phi);
        x0 = cosPhi * cos$1(lambda);
        y0 = cosPhi * sin$1(lambda);
        z0 = sin$1(phi);
        centroidStream.point = centroidLinePoint;
        centroidPointCartesian(x0, y0, z0);
    }

    function centroidLinePoint(lambda, phi) {
        lambda *= radians, phi *= radians;
        var cosPhi = cos$1(phi),
            x = cosPhi * cos$1(lambda),
            y = cosPhi * sin$1(lambda),
            z = sin$1(phi),
            w = atan2(sqrt((w = y0 * z - z0 * y) * w + (w = z0 * x - x0 * z) * w + (w = x0 * y - y0 * x) * w), x0 * x + y0 * y + z0 * z);
        W1 += w;
        X1 += w * (x0 + (x0 = x));
        Y1 += w * (y0 + (y0 = y));
        Z1 += w * (z0 + (z0 = z));
        centroidPointCartesian(x0, y0, z0);
    }

    function centroidLineEnd() {
        centroidStream.point = centroidPoint;
    }

// See J. E. Brock, The Inertia Tensor for a Spherical Triangle,
// J. Applied Mechanics 42, 239 (1975).
    function centroidRingStart() {
        centroidStream.point = centroidRingPointFirst;
    }

    function centroidRingEnd() {
        centroidRingPoint(lambda00$2, phi00$2);
        centroidStream.point = centroidPoint;
    }

    function centroidRingPointFirst(lambda, phi) {
        lambda00$2 = lambda, phi00$2 = phi;
        lambda *= radians, phi *= radians;
        centroidStream.point = centroidRingPoint;
        var cosPhi = cos$1(phi);
        x0 = cosPhi * cos$1(lambda);
        y0 = cosPhi * sin$1(lambda);
        z0 = sin$1(phi);
        centroidPointCartesian(x0, y0, z0);
    }

    function centroidRingPoint(lambda, phi) {
        lambda *= radians, phi *= radians;
        var cosPhi = cos$1(phi),
            x = cosPhi * cos$1(lambda),
            y = cosPhi * sin$1(lambda),
            z = sin$1(phi),
            cx = y0 * z - z0 * y,
            cy = z0 * x - x0 * z,
            cz = x0 * y - y0 * x,
            m = sqrt(cx * cx + cy * cy + cz * cz),
            w = asin(m), // line weight = angle
            v = m && -w / m; // area weight multiplier
        X2 += v * cx;
        Y2 += v * cy;
        Z2 += v * cz;
        W1 += w;
        X1 += w * (x0 + (x0 = x));
        Y1 += w * (y0 + (y0 = y));
        Z1 += w * (z0 + (z0 = z));
        centroidPointCartesian(x0, y0, z0);
    }

    function centroid(object) {
        W0 = W1 =
            X0 = Y0 = Z0 =
                X1 = Y1 = Z1 =
                    X2 = Y2 = Z2 = 0;
        geoStream(object, centroidStream);

        var x = X2,
            y = Y2,
            z = Z2,
            m = x * x + y * y + z * z;

        // If the area-weighted ccentroid is undefined, fall back to length-weighted ccentroid.
        if (m < epsilon2$1) {
            x = X1, y = Y1, z = Z1;
            // If the feature has zero length, fall back to arithmetic mean of point vectors.
            if (W1 < epsilon$2) x = X0, y = Y0, z = Z0;
            m = x * x + y * y + z * z;
            // If the feature still has an undefined ccentroid, then return.
            if (m < epsilon2$1) return [NaN, NaN];
        }

        return [atan2(y, x) * degrees$1, asin(z / sqrt(m)) * degrees$1];
    }

    function constant$7(x) {
        return function() {
            return x;
        };
    }

    function compose(a, b) {

        function compose(x, y) {
            return x = a(x, y), b(x[0], x[1]);
        }

        if (a.invert && b.invert) compose.invert = function(x, y) {
            return x = b.invert(x, y), x && a.invert(x[0], x[1]);
        };

        return compose;
    }

    function rotationIdentity(lambda, phi) {
        return [lambda > pi$3 ? lambda - tau$3 : lambda < -pi$3 ? lambda + tau$3 : lambda, phi];
    }

    rotationIdentity.invert = rotationIdentity;

    function rotateRadians(deltaLambda, deltaPhi, deltaGamma) {
        return (deltaLambda %= tau$3) ? (deltaPhi || deltaGamma ? compose(rotationLambda(deltaLambda), rotationPhiGamma(deltaPhi, deltaGamma))
            : rotationLambda(deltaLambda))
            : (deltaPhi || deltaGamma ? rotationPhiGamma(deltaPhi, deltaGamma)
                : rotationIdentity);
    }

    function forwardRotationLambda(deltaLambda) {
        return function(lambda, phi) {
            return lambda += deltaLambda, [lambda > pi$3 ? lambda - tau$3 : lambda < -pi$3 ? lambda + tau$3 : lambda, phi];
        };
    }

    function rotationLambda(deltaLambda) {
        var rotation = forwardRotationLambda(deltaLambda);
        rotation.invert = forwardRotationLambda(-deltaLambda);
        return rotation;
    }

    function rotationPhiGamma(deltaPhi, deltaGamma) {
        var cosDeltaPhi = cos$1(deltaPhi),
            sinDeltaPhi = sin$1(deltaPhi),
            cosDeltaGamma = cos$1(deltaGamma),
            sinDeltaGamma = sin$1(deltaGamma);

        function rotation(lambda, phi) {
            var cosPhi = cos$1(phi),
                x = cos$1(lambda) * cosPhi,
                y = sin$1(lambda) * cosPhi,
                z = sin$1(phi),
                k = z * cosDeltaPhi + x * sinDeltaPhi;
            return [
                atan2(y * cosDeltaGamma - k * sinDeltaGamma, x * cosDeltaPhi - z * sinDeltaPhi),
                asin(k * cosDeltaGamma + y * sinDeltaGamma)
            ];
        }

        rotation.invert = function(lambda, phi) {
            var cosPhi = cos$1(phi),
                x = cos$1(lambda) * cosPhi,
                y = sin$1(lambda) * cosPhi,
                z = sin$1(phi),
                k = z * cosDeltaGamma - y * sinDeltaGamma;
            return [
                atan2(y * cosDeltaGamma + z * sinDeltaGamma, x * cosDeltaPhi + k * sinDeltaPhi),
                asin(k * cosDeltaPhi - x * sinDeltaPhi)
            ];
        };

        return rotation;
    }

    function rotation(rotate) {
        rotate = rotateRadians(rotate[0] * radians, rotate[1] * radians, rotate.length > 2 ? rotate[2] * radians : 0);

        function forward(coordinates) {
            coordinates = rotate(coordinates[0] * radians, coordinates[1] * radians);
            return coordinates[0] *= degrees$1, coordinates[1] *= degrees$1, coordinates;
        }

        forward.invert = function(coordinates) {
            coordinates = rotate.invert(coordinates[0] * radians, coordinates[1] * radians);
            return coordinates[0] *= degrees$1, coordinates[1] *= degrees$1, coordinates;
        };

        return forward;
    }

// Generates a circle centered at [0°, 0°], with a given radius and precision.
    function circleStream(stream, radius, delta, direction, t0, t1) {
        if (!delta) return;
        var cosRadius = cos$1(radius),
            sinRadius = sin$1(radius),
            step = direction * delta;
        if (t0 == null) {
            t0 = radius + direction * tau$3;
            t1 = radius - step / 2;
        } else {
            t0 = circleRadius(cosRadius, t0);
            t1 = circleRadius(cosRadius, t1);
            if (direction > 0 ? t0 < t1 : t0 > t1) t0 += direction * tau$3;
        }
        for (var point, t = t0; direction > 0 ? t > t1 : t < t1; t -= step) {
            point = spherical([cosRadius, -sinRadius * cos$1(t), -sinRadius * sin$1(t)]);
            stream.point(point[0], point[1]);
        }
    }

// Returns the signed angle of a cartesian point relative to [cosRadius, 0, 0].
    function circleRadius(cosRadius, point) {
        point = cartesian(point), point[0] -= cosRadius;
        cartesianNormalizeInPlace(point);
        var radius = acos(-point[1]);
        return ((-point[2] < 0 ? -radius : radius) + tau$3 - epsilon$2) % tau$3;
    }

    function circle() {
        var center = constant$7([0, 0]),
            radius = constant$7(90),
            precision = constant$7(6),
            ring,
            rotate,
            stream = {point: point};

        function point(x, y) {
            ring.push(x = rotate(x, y));
            x[0] *= degrees$1, x[1] *= degrees$1;
        }

        function circle() {
            var c = center.apply(this, arguments),
                r = radius.apply(this, arguments) * radians,
                p = precision.apply(this, arguments) * radians;
            ring = [];
            rotate = rotateRadians(-c[0] * radians, -c[1] * radians, 0).invert;
            circleStream(stream, r, p, 1);
            c = {type: "Polygon", coordinates: [ring]};
            ring = rotate = null;
            return c;
        }

        circle.center = function(_) {
            return arguments.length ? (center = typeof _ === "function" ? _ : constant$7([+_[0], +_[1]]), circle) : center;
        };

        circle.radius = function(_) {
            return arguments.length ? (radius = typeof _ === "function" ? _ : constant$7(+_), circle) : radius;
        };

        circle.precision = function(_) {
            return arguments.length ? (precision = typeof _ === "function" ? _ : constant$7(+_), circle) : precision;
        };

        return circle;
    }

    function clipBuffer() {
        var lines = [],
            line;
        return {
            point: function(x, y) {
                line.push([x, y]);
            },
            lineStart: function() {
                lines.push(line = []);
            },
            lineEnd: noop$1,
            rejoin: function() {
                if (lines.length > 1) lines.push(lines.pop().concat(lines.shift()));
            },
            result: function() {
                var result = lines;
                lines = [];
                line = null;
                return result;
            }
        };
    }

    function pointEqual(a, b) {
        return abs(a[0] - b[0]) < epsilon$2 && abs(a[1] - b[1]) < epsilon$2;
    }

    function Intersection(point, points, other, entry) {
        this.x = point;
        this.z = points;
        this.o = other; // another intersection
        this.e = entry; // is an entry?
        this.v = false; // visited
        this.n = this.p = null; // next & previous
    }

// A generalized polygon clipping algorithm: given a polygon that has been cut
// into its visible line segments, and rejoins the segments by interpolating
// along the clip edge.
    function clipRejoin(segments, compareIntersection, startInside, interpolate, stream) {
        var subject = [],
            clip = [],
            i,
            n;

        segments.forEach(function(segment) {
            if ((n = segment.length - 1) <= 0) return;
            var n, p0 = segment[0], p1 = segment[n], x;

            // If the first and last points of a segment are coincident, then treat as a
            // closed ring. TODO if all rings are closed, then the winding order of the
            // exterior ring should be checked.
            if (pointEqual(p0, p1)) {
                stream.lineStart();
                for (i = 0; i < n; ++i) stream.point((p0 = segment[i])[0], p0[1]);
                stream.lineEnd();
                return;
            }

            subject.push(x = new Intersection(p0, segment, null, true));
            clip.push(x.o = new Intersection(p0, null, x, false));
            subject.push(x = new Intersection(p1, segment, null, false));
            clip.push(x.o = new Intersection(p1, null, x, true));
        });

        if (!subject.length) return;

        clip.sort(compareIntersection);
        link$1(subject);
        link$1(clip);

        for (i = 0, n = clip.length; i < n; ++i) {
            clip[i].e = startInside = !startInside;
        }

        var start = subject[0],
            points,
            point;

        while (1) {
            // Find first unvisited intersection.
            var current = start,
                isSubject = true;
            while (current.v) if ((current = current.n) === start) return;
            points = current.z;
            stream.lineStart();
            do {
                current.v = current.o.v = true;
                if (current.e) {
                    if (isSubject) {
                        for (i = 0, n = points.length; i < n; ++i) stream.point((point = points[i])[0], point[1]);
                    } else {
                        interpolate(current.x, current.n.x, 1, stream);
                    }
                    current = current.n;
                } else {
                    if (isSubject) {
                        points = current.p.z;
                        for (i = points.length - 1; i >= 0; --i) stream.point((point = points[i])[0], point[1]);
                    } else {
                        interpolate(current.x, current.p.x, -1, stream);
                    }
                    current = current.p;
                }
                current = current.o;
                points = current.z;
                isSubject = !isSubject;
            } while (!current.v);
            stream.lineEnd();
        }
    }

    function link$1(array) {
        if (!(n = array.length)) return;
        var n,
            i = 0,
            a = array[0],
            b;
        while (++i < n) {
            a.n = b = array[i];
            b.p = a;
            a = b;
        }
        a.n = b = array[0];
        b.p = a;
    }

    var sum$1 = adder();

    function polygonContains(polygon, point) {
        var lambda = point[0],
            phi = point[1],
            normal = [sin$1(lambda), -cos$1(lambda), 0],
            angle = 0,
            winding = 0;

        sum$1.reset();

        for (var i = 0, n = polygon.length; i < n; ++i) {
            if (!(m = (ring = polygon[i]).length)) continue;
            var ring,
                m,
                point0 = ring[m - 1],
                lambda0 = point0[0],
                phi0 = point0[1] / 2 + quarterPi,
                sinPhi0 = sin$1(phi0),
                cosPhi0 = cos$1(phi0);

            for (var j = 0; j < m; ++j, lambda0 = lambda1, sinPhi0 = sinPhi1, cosPhi0 = cosPhi1, point0 = point1) {
                var point1 = ring[j],
                    lambda1 = point1[0],
                    phi1 = point1[1] / 2 + quarterPi,
                    sinPhi1 = sin$1(phi1),
                    cosPhi1 = cos$1(phi1),
                    delta = lambda1 - lambda0,
                    sign$$1 = delta >= 0 ? 1 : -1,
                    absDelta = sign$$1 * delta,
                    antimeridian = absDelta > pi$3,
                    k = sinPhi0 * sinPhi1;

                sum$1.add(atan2(k * sign$$1 * sin$1(absDelta), cosPhi0 * cosPhi1 + k * cos$1(absDelta)));
                angle += antimeridian ? delta + sign$$1 * tau$3 : delta;

                // Are the longitudes either side of the point’s meridian (lambda),
                // and are the latitudes smaller than the parallel (phi)?
                if (antimeridian ^ lambda0 >= lambda ^ lambda1 >= lambda) {
                    var arc = cartesianCross(cartesian(point0), cartesian(point1));
                    cartesianNormalizeInPlace(arc);
                    var intersection = cartesianCross(normal, arc);
                    cartesianNormalizeInPlace(intersection);
                    var phiArc = (antimeridian ^ delta >= 0 ? -1 : 1) * asin(intersection[2]);
                    if (phi > phiArc || phi === phiArc && (arc[0] || arc[1])) {
                        winding += antimeridian ^ delta >= 0 ? 1 : -1;
                    }
                }
            }
        }

        // First, determine whether the South pole is inside or outside:
        //
        // It is inside if:
        // * the polygon winds around it in a clockwise direction.
        // * the polygon does not (cumulatively) wind around it, but has a negative
        //   (counter-clockwise) area.
        //
        // Second, count the (signed) number of times a segment crosses a lambda
        // from the point to the South pole.  If it is zero, then the point is the
        // same side as the South pole.

        return (angle < -epsilon$2 || angle < epsilon$2 && sum$1 < -epsilon$2) ^ (winding & 1);
    }

    function clip(pointVisible, clipLine, interpolate, start) {
        return function(sink) {
            var line = clipLine(sink),
                ringBuffer = clipBuffer(),
                ringSink = clipLine(ringBuffer),
                polygonStarted = false,
                polygon,
                segments,
                ring;

            var clip = {
                point: point,
                lineStart: lineStart,
                lineEnd: lineEnd,
                polygonStart: function() {
                    clip.point = pointRing;
                    clip.lineStart = ringStart;
                    clip.lineEnd = ringEnd;
                    segments = [];
                    polygon = [];
                },
                polygonEnd: function() {
                    clip.point = point;
                    clip.lineStart = lineStart;
                    clip.lineEnd = lineEnd;
                    segments = merge(segments);
                    var startInside = polygonContains(polygon, start);
                    if (segments.length) {
                        if (!polygonStarted) sink.polygonStart(), polygonStarted = true;
                        clipRejoin(segments, compareIntersection, startInside, interpolate, sink);
                    } else if (startInside) {
                        if (!polygonStarted) sink.polygonStart(), polygonStarted = true;
                        sink.lineStart();
                        interpolate(null, null, 1, sink);
                        sink.lineEnd();
                    }
                    if (polygonStarted) sink.polygonEnd(), polygonStarted = false;
                    segments = polygon = null;
                },
                sphere: function() {
                    sink.polygonStart();
                    sink.lineStart();
                    interpolate(null, null, 1, sink);
                    sink.lineEnd();
                    sink.polygonEnd();
                }
            };

            function point(lambda, phi) {
                if (pointVisible(lambda, phi)) sink.point(lambda, phi);
            }

            function pointLine(lambda, phi) {
                line.point(lambda, phi);
            }

            function lineStart() {
                clip.point = pointLine;
                line.lineStart();
            }

            function lineEnd() {
                clip.point = point;
                line.lineEnd();
            }

            function pointRing(lambda, phi) {
                ring.push([lambda, phi]);
                ringSink.point(lambda, phi);
            }

            function ringStart() {
                ringSink.lineStart();
                ring = [];
            }

            function ringEnd() {
                pointRing(ring[0][0], ring[0][1]);
                ringSink.lineEnd();

                var clean = ringSink.clean(),
                    ringSegments = ringBuffer.result(),
                    i, n = ringSegments.length, m,
                    segment,
                    point;

                ring.pop();
                polygon.push(ring);
                ring = null;

                if (!n) return;

                // No intersections.
                if (clean & 1) {
                    segment = ringSegments[0];
                    if ((m = segment.length - 1) > 0) {
                        if (!polygonStarted) sink.polygonStart(), polygonStarted = true;
                        sink.lineStart();
                        for (i = 0; i < m; ++i) sink.point((point = segment[i])[0], point[1]);
                        sink.lineEnd();
                    }
                    return;
                }

                // Rejoin connected segments.
                // TODO reuse ringBuffer.rejoin()?
                if (n > 1 && clean & 2) ringSegments.push(ringSegments.pop().concat(ringSegments.shift()));

                segments.push(ringSegments.filter(validSegment));
            }

            return clip;
        };
    }

    function validSegment(segment) {
        return segment.length > 1;
    }

// Intersections are sorted along the clip edge. For both antimeridian cutting
// and circle clipping, the same comparison is used.
    function compareIntersection(a, b) {
        return ((a = a.x)[0] < 0 ? a[1] - halfPi$2 - epsilon$2 : halfPi$2 - a[1])
            - ((b = b.x)[0] < 0 ? b[1] - halfPi$2 - epsilon$2 : halfPi$2 - b[1]);
    }

    var clipAntimeridian = clip(
        function() { return true; },
        clipAntimeridianLine,
        clipAntimeridianInterpolate,
        [-pi$3, -halfPi$2]
    );

// Takes a line and cuts into visible segments. Return values: 0 - there were
// intersections or the line was empty; 1 - no intersections; 2 - there were
// intersections, and the first and last segments should be rejoined.
    function clipAntimeridianLine(stream) {
        var lambda0 = NaN,
            phi0 = NaN,
            sign0 = NaN,
            clean; // no intersections

        return {
            lineStart: function() {
                stream.lineStart();
                clean = 1;
            },
            point: function(lambda1, phi1) {
                var sign1 = lambda1 > 0 ? pi$3 : -pi$3,
                    delta = abs(lambda1 - lambda0);
                if (abs(delta - pi$3) < epsilon$2) { // line crosses a pole
                    stream.point(lambda0, phi0 = (phi0 + phi1) / 2 > 0 ? halfPi$2 : -halfPi$2);
                    stream.point(sign0, phi0);
                    stream.lineEnd();
                    stream.lineStart();
                    stream.point(sign1, phi0);
                    stream.point(lambda1, phi0);
                    clean = 0;
                } else if (sign0 !== sign1 && delta >= pi$3) { // line crosses antimeridian
                    if (abs(lambda0 - sign0) < epsilon$2) lambda0 -= sign0 * epsilon$2; // handle degeneracies
                    if (abs(lambda1 - sign1) < epsilon$2) lambda1 -= sign1 * epsilon$2;
                    phi0 = clipAntimeridianIntersect(lambda0, phi0, lambda1, phi1);
                    stream.point(sign0, phi0);
                    stream.lineEnd();
                    stream.lineStart();
                    stream.point(sign1, phi0);
                    clean = 0;
                }
                stream.point(lambda0 = lambda1, phi0 = phi1);
                sign0 = sign1;
            },
            lineEnd: function() {
                stream.lineEnd();
                lambda0 = phi0 = NaN;
            },
            clean: function() {
                return 2 - clean; // if intersections, rejoin first and last segments
            }
        };
    }

    function clipAntimeridianIntersect(lambda0, phi0, lambda1, phi1) {
        var cosPhi0,
            cosPhi1,
            sinLambda0Lambda1 = sin$1(lambda0 - lambda1);
        return abs(sinLambda0Lambda1) > epsilon$2
            ? atan((sin$1(phi0) * (cosPhi1 = cos$1(phi1)) * sin$1(lambda1)
                - sin$1(phi1) * (cosPhi0 = cos$1(phi0)) * sin$1(lambda0))
                / (cosPhi0 * cosPhi1 * sinLambda0Lambda1))
            : (phi0 + phi1) / 2;
    }

    function clipAntimeridianInterpolate(from, to, direction, stream) {
        var phi;
        if (from == null) {
            phi = direction * halfPi$2;
            stream.point(-pi$3, phi);
            stream.point(0, phi);
            stream.point(pi$3, phi);
            stream.point(pi$3, 0);
            stream.point(pi$3, -phi);
            stream.point(0, -phi);
            stream.point(-pi$3, -phi);
            stream.point(-pi$3, 0);
            stream.point(-pi$3, phi);
        } else if (abs(from[0] - to[0]) > epsilon$2) {
            var lambda = from[0] < to[0] ? pi$3 : -pi$3;
            phi = direction * lambda / 2;
            stream.point(-lambda, phi);
            stream.point(0, phi);
            stream.point(lambda, phi);
        } else {
            stream.point(to[0], to[1]);
        }
    }

    function clipCircle(radius) {
        var cr = cos$1(radius),
            delta = 6 * radians,
            smallRadius = cr > 0,
            notHemisphere = abs(cr) > epsilon$2; // TODO optimise for this common case

        function interpolate(from, to, direction, stream) {
            circleStream(stream, radius, delta, direction, from, to);
        }

        function visible(lambda, phi) {
            return cos$1(lambda) * cos$1(phi) > cr;
        }

        // Takes a line and cuts into visible segments. Return values used for polygon
        // clipping: 0 - there were intersections or the line was empty; 1 - no
        // intersections 2 - there were intersections, and the first and last segments
        // should be rejoined.
        function clipLine(stream) {
            var point0, // previous point
                c0, // code for previous point
                v0, // visibility of previous point
                v00, // visibility of first point
                clean; // no intersections
            return {
                lineStart: function() {
                    v00 = v0 = false;
                    clean = 1;
                },
                point: function(lambda, phi) {
                    var point1 = [lambda, phi],
                        point2,
                        v = visible(lambda, phi),
                        c = smallRadius
                            ? v ? 0 : code(lambda, phi)
                            : v ? code(lambda + (lambda < 0 ? pi$3 : -pi$3), phi) : 0;
                    if (!point0 && (v00 = v0 = v)) stream.lineStart();
                    // Handle degeneracies.
                    // TODO ignore if not clipping polygons.
                    if (v !== v0) {
                        point2 = intersect(point0, point1);
                        if (!point2 || pointEqual(point0, point2) || pointEqual(point1, point2)) {
                            point1[0] += epsilon$2;
                            point1[1] += epsilon$2;
                            v = visible(point1[0], point1[1]);
                        }
                    }
                    if (v !== v0) {
                        clean = 0;
                        if (v) {
                            // outside going in
                            stream.lineStart();
                            point2 = intersect(point1, point0);
                            stream.point(point2[0], point2[1]);
                        } else {
                            // inside going out
                            point2 = intersect(point0, point1);
                            stream.point(point2[0], point2[1]);
                            stream.lineEnd();
                        }
                        point0 = point2;
                    } else if (notHemisphere && point0 && smallRadius ^ v) {
                        var t;
                        // If the codes for two points are different, or are both zero,
                        // and there this segment intersects with the small circle.
                        if (!(c & c0) && (t = intersect(point1, point0, true))) {
                            clean = 0;
                            if (smallRadius) {
                                stream.lineStart();
                                stream.point(t[0][0], t[0][1]);
                                stream.point(t[1][0], t[1][1]);
                                stream.lineEnd();
                            } else {
                                stream.point(t[1][0], t[1][1]);
                                stream.lineEnd();
                                stream.lineStart();
                                stream.point(t[0][0], t[0][1]);
                            }
                        }
                    }
                    if (v && (!point0 || !pointEqual(point0, point1))) {
                        stream.point(point1[0], point1[1]);
                    }
                    point0 = point1, v0 = v, c0 = c;
                },
                lineEnd: function() {
                    if (v0) stream.lineEnd();
                    point0 = null;
                },
                // Rejoin first and last segments if there were intersections and the first
                // and last points were visible.
                clean: function() {
                    return clean | ((v00 && v0) << 1);
                }
            };
        }

        // Intersects the great circle between a and b with the clip circle.
        function intersect(a, b, two) {
            var pa = cartesian(a),
                pb = cartesian(b);

            // We have two planes, n1.p = d1 and n2.p = d2.
            // Find intersection line p(t) = c1 n1 + c2 n2 + t (n1 ⨯ n2).
            var n1 = [1, 0, 0], // normal
                n2 = cartesianCross(pa, pb),
                n2n2 = cartesianDot(n2, n2),
                n1n2 = n2[0], // cartesianDot(n1, n2),
                determinant = n2n2 - n1n2 * n1n2;

            // Two polar points.
            if (!determinant) return !two && a;

            var c1 =  cr * n2n2 / determinant,
                c2 = -cr * n1n2 / determinant,
                n1xn2 = cartesianCross(n1, n2),
                A = cartesianScale(n1, c1),
                B = cartesianScale(n2, c2);
            cartesianAddInPlace(A, B);

            // Solve |p(t)|^2 = 1.
            var u = n1xn2,
                w = cartesianDot(A, u),
                uu = cartesianDot(u, u),
                t2 = w * w - uu * (cartesianDot(A, A) - 1);

            if (t2 < 0) return;

            var t = sqrt(t2),
                q = cartesianScale(u, (-w - t) / uu);
            cartesianAddInPlace(q, A);
            q = spherical(q);

            if (!two) return q;

            // Two intersection points.
            var lambda0 = a[0],
                lambda1 = b[0],
                phi0 = a[1],
                phi1 = b[1],
                z;

            if (lambda1 < lambda0) z = lambda0, lambda0 = lambda1, lambda1 = z;

            var delta = lambda1 - lambda0,
                polar = abs(delta - pi$3) < epsilon$2,
                meridian = polar || delta < epsilon$2;

            if (!polar && phi1 < phi0) z = phi0, phi0 = phi1, phi1 = z;

            // Check that the first point is between a and b.
            if (meridian
                ? polar
                    ? phi0 + phi1 > 0 ^ q[1] < (abs(q[0] - lambda0) < epsilon$2 ? phi0 : phi1)
                    : phi0 <= q[1] && q[1] <= phi1
                : delta > pi$3 ^ (lambda0 <= q[0] && q[0] <= lambda1)) {
                var q1 = cartesianScale(u, (-w + t) / uu);
                cartesianAddInPlace(q1, A);
                return [q, spherical(q1)];
            }
        }

        // Generates a 4-bit vector representing the location of a point relative to
        // the small circle's bounding box.
        function code(lambda, phi) {
            var r = smallRadius ? radius : pi$3 - radius,
                code = 0;
            if (lambda < -r) code |= 1; // left
            else if (lambda > r) code |= 2; // right
            if (phi < -r) code |= 4; // below
            else if (phi > r) code |= 8; // above
            return code;
        }

        return clip(visible, clipLine, interpolate, smallRadius ? [0, -radius] : [-pi$3, radius - pi$3]);
    }

    function clipLine(a, b, x0, y0, x1, y1) {
        var ax = a[0],
            ay = a[1],
            bx = b[0],
            by = b[1],
            t0 = 0,
            t1 = 1,
            dx = bx - ax,
            dy = by - ay,
            r;

        r = x0 - ax;
        if (!dx && r > 0) return;
        r /= dx;
        if (dx < 0) {
            if (r < t0) return;
            if (r < t1) t1 = r;
        } else if (dx > 0) {
            if (r > t1) return;
            if (r > t0) t0 = r;
        }

        r = x1 - ax;
        if (!dx && r < 0) return;
        r /= dx;
        if (dx < 0) {
            if (r > t1) return;
            if (r > t0) t0 = r;
        } else if (dx > 0) {
            if (r < t0) return;
            if (r < t1) t1 = r;
        }

        r = y0 - ay;
        if (!dy && r > 0) return;
        r /= dy;
        if (dy < 0) {
            if (r < t0) return;
            if (r < t1) t1 = r;
        } else if (dy > 0) {
            if (r > t1) return;
            if (r > t0) t0 = r;
        }

        r = y1 - ay;
        if (!dy && r < 0) return;
        r /= dy;
        if (dy < 0) {
            if (r > t1) return;
            if (r > t0) t0 = r;
        } else if (dy > 0) {
            if (r < t0) return;
            if (r < t1) t1 = r;
        }

        if (t0 > 0) a[0] = ax + t0 * dx, a[1] = ay + t0 * dy;
        if (t1 < 1) b[0] = ax + t1 * dx, b[1] = ay + t1 * dy;
        return true;
    }

    var clipMax = 1e9;
    var clipMin = -clipMax;

// TODO Use d3-polygon’s polygonContains here for the ring check?
// TODO Eliminate duplicate buffering in clipBuffer and polygon.push?

    function clipRectangle(x0, y0, x1, y1) {

        function visible(x, y) {
            return x0 <= x && x <= x1 && y0 <= y && y <= y1;
        }

        function interpolate(from, to, direction, stream) {
            var a = 0, a1 = 0;
            if (from == null
                || (a = corner(from, direction)) !== (a1 = corner(to, direction))
                || comparePoint(from, to) < 0 ^ direction > 0) {
                do stream.point(a === 0 || a === 3 ? x0 : x1, a > 1 ? y1 : y0);
                while ((a = (a + direction + 4) % 4) !== a1);
            } else {
                stream.point(to[0], to[1]);
            }
        }

        function corner(p, direction) {
            return abs(p[0] - x0) < epsilon$2 ? direction > 0 ? 0 : 3
                : abs(p[0] - x1) < epsilon$2 ? direction > 0 ? 2 : 1
                    : abs(p[1] - y0) < epsilon$2 ? direction > 0 ? 1 : 0
                        : direction > 0 ? 3 : 2; // abs(p[1] - y1) < epsilon
        }

        function compareIntersection(a, b) {
            return comparePoint(a.x, b.x);
        }

        function comparePoint(a, b) {
            var ca = corner(a, 1),
                cb = corner(b, 1);
            return ca !== cb ? ca - cb
                : ca === 0 ? b[1] - a[1]
                    : ca === 1 ? a[0] - b[0]
                        : ca === 2 ? a[1] - b[1]
                            : b[0] - a[0];
        }

        return function(stream) {
            var activeStream = stream,
                bufferStream = clipBuffer(),
                segments,
                polygon,
                ring,
                x__, y__, v__, // first point
                x_, y_, v_, // previous point
                first,
                clean;

            var clipStream = {
                point: point,
                lineStart: lineStart,
                lineEnd: lineEnd,
                polygonStart: polygonStart,
                polygonEnd: polygonEnd
            };

            function point(x, y) {
                if (visible(x, y)) activeStream.point(x, y);
            }

            function polygonInside() {
                var winding = 0;

                for (var i = 0, n = polygon.length; i < n; ++i) {
                    for (var ring = polygon[i], j = 1, m = ring.length, point = ring[0], a0, a1, b0 = point[0], b1 = point[1]; j < m; ++j) {
                        a0 = b0, a1 = b1, point = ring[j], b0 = point[0], b1 = point[1];
                        if (a1 <= y1) { if (b1 > y1 && (b0 - a0) * (y1 - a1) > (b1 - a1) * (x0 - a0)) ++winding; }
                        else { if (b1 <= y1 && (b0 - a0) * (y1 - a1) < (b1 - a1) * (x0 - a0)) --winding; }
                    }
                }

                return winding;
            }

            // Buffer geometry within a polygon and then clip it en masse.
            function polygonStart() {
                activeStream = bufferStream, segments = [], polygon = [], clean = true;
            }

            function polygonEnd() {
                var startInside = polygonInside(),
                    cleanInside = clean && startInside,
                    visible = (segments = merge(segments)).length;
                if (cleanInside || visible) {
                    stream.polygonStart();
                    if (cleanInside) {
                        stream.lineStart();
                        interpolate(null, null, 1, stream);
                        stream.lineEnd();
                    }
                    if (visible) {
                        clipRejoin(segments, compareIntersection, startInside, interpolate, stream);
                    }
                    stream.polygonEnd();
                }
                activeStream = stream, segments = polygon = ring = null;
            }

            function lineStart() {
                clipStream.point = linePoint;
                if (polygon) polygon.push(ring = []);
                first = true;
                v_ = false;
                x_ = y_ = NaN;
            }

            // TODO rather than special-case polygons, simply handle them separately.
            // Ideally, coincident intersection points should be jittered to avoid
            // clipping issues.
            function lineEnd() {
                if (segments) {
                    linePoint(x__, y__);
                    if (v__ && v_) bufferStream.rejoin();
                    segments.push(bufferStream.result());
                }
                clipStream.point = point;
                if (v_) activeStream.lineEnd();
            }

            function linePoint(x, y) {
                var v = visible(x, y);
                if (polygon) ring.push([x, y]);
                if (first) {
                    x__ = x, y__ = y, v__ = v;
                    first = false;
                    if (v) {
                        activeStream.lineStart();
                        activeStream.point(x, y);
                    }
                } else {
                    if (v && v_) activeStream.point(x, y);
                    else {
                        var a = [x_ = Math.max(clipMin, Math.min(clipMax, x_)), y_ = Math.max(clipMin, Math.min(clipMax, y_))],
                            b = [x = Math.max(clipMin, Math.min(clipMax, x)), y = Math.max(clipMin, Math.min(clipMax, y))];
                        if (clipLine(a, b, x0, y0, x1, y1)) {
                            if (!v_) {
                                activeStream.lineStart();
                                activeStream.point(a[0], a[1]);
                            }
                            activeStream.point(b[0], b[1]);
                            if (!v) activeStream.lineEnd();
                            clean = false;
                        } else if (v) {
                            activeStream.lineStart();
                            activeStream.point(x, y);
                            clean = false;
                        }
                    }
                }
                x_ = x, y_ = y, v_ = v;
            }

            return clipStream;
        };
    }

    function extent$1() {
        var x0 = 0,
            y0 = 0,
            x1 = 960,
            y1 = 500,
            cache,
            cacheStream,
            clip;

        return clip = {
            stream: function(stream) {
                return cache && cacheStream === stream ? cache : cache = clipRectangle(x0, y0, x1, y1)(cacheStream = stream);
            },
            extent: function(_) {
                return arguments.length ? (x0 = +_[0][0], y0 = +_[0][1], x1 = +_[1][0], y1 = +_[1][1], cache = cacheStream = null, clip) : [[x0, y0], [x1, y1]];
            }
        };
    }

    var lengthSum = adder();
    var lambda0$2;
    var sinPhi0$1;
    var cosPhi0$1;

    var lengthStream = {
        sphere: noop$1,
        point: noop$1,
        lineStart: lengthLineStart,
        lineEnd: noop$1,
        polygonStart: noop$1,
        polygonEnd: noop$1
    };

    function lengthLineStart() {
        lengthStream.point = lengthPointFirst;
        lengthStream.lineEnd = lengthLineEnd;
    }

    function lengthLineEnd() {
        lengthStream.point = lengthStream.lineEnd = noop$1;
    }

    function lengthPointFirst(lambda, phi) {
        lambda *= radians, phi *= radians;
        lambda0$2 = lambda, sinPhi0$1 = sin$1(phi), cosPhi0$1 = cos$1(phi);
        lengthStream.point = lengthPoint;
    }

    function lengthPoint(lambda, phi) {
        lambda *= radians, phi *= radians;
        var sinPhi = sin$1(phi),
            cosPhi = cos$1(phi),
            delta = abs(lambda - lambda0$2),
            cosDelta = cos$1(delta),
            sinDelta = sin$1(delta),
            x = cosPhi * sinDelta,
            y = cosPhi0$1 * sinPhi - sinPhi0$1 * cosPhi * cosDelta,
            z = sinPhi0$1 * sinPhi + cosPhi0$1 * cosPhi * cosDelta;
        lengthSum.add(atan2(sqrt(x * x + y * y), z));
        lambda0$2 = lambda, sinPhi0$1 = sinPhi, cosPhi0$1 = cosPhi;
    }

    function length$1(object) {
        lengthSum.reset();
        geoStream(object, lengthStream);
        return +lengthSum;
    }

    var coordinates = [null, null];
    var object$1 = {type: "LineString", coordinates: coordinates};

    function distance(a, b) {
        coordinates[0] = a;
        coordinates[1] = b;
        return length$1(object$1);
    }

    var containsObjectType = {
        Feature: function(object, point) {
            return containsGeometry(object.geometry, point);
        },
        FeatureCollection: function(object, point) {
            var features = object.features, i = -1, n = features.length;
            while (++i < n) if (containsGeometry(features[i].geometry, point)) return true;
            return false;
        }
    };

    var containsGeometryType = {
        Sphere: function() {
            return true;
        },
        Point: function(object, point) {
            return containsPoint(object.coordinates, point);
        },
        MultiPoint: function(object, point) {
            var coordinates = object.coordinates, i = -1, n = coordinates.length;
            while (++i < n) if (containsPoint(coordinates[i], point)) return true;
            return false;
        },
        LineString: function(object, point) {
            return containsLine(object.coordinates, point);
        },
        MultiLineString: function(object, point) {
            var coordinates = object.coordinates, i = -1, n = coordinates.length;
            while (++i < n) if (containsLine(coordinates[i], point)) return true;
            return false;
        },
        Polygon: function(object, point) {
            return containsPolygon(object.coordinates, point);
        },
        MultiPolygon: function(object, point) {
            var coordinates = object.coordinates, i = -1, n = coordinates.length;
            while (++i < n) if (containsPolygon(coordinates[i], point)) return true;
            return false;
        },
        GeometryCollection: function(object, point) {
            var geometries = object.geometries, i = -1, n = geometries.length;
            while (++i < n) if (containsGeometry(geometries[i], point)) return true;
            return false;
        }
    };

    function containsGeometry(geometry, point) {
        return geometry && containsGeometryType.hasOwnProperty(geometry.type)
            ? containsGeometryType[geometry.type](geometry, point)
            : false;
    }

    function containsPoint(coordinates, point) {
        return distance(coordinates, point) === 0;
    }

    function containsLine(coordinates, point) {
        var ab = distance(coordinates[0], coordinates[1]),
            ao = distance(coordinates[0], point),
            ob = distance(point, coordinates[1]);
        return ao + ob <= ab + epsilon$2;
    }

    function containsPolygon(coordinates, point) {
        return !!polygonContains(coordinates.map(ringRadians), pointRadians(point));
    }

    function ringRadians(ring) {
        return ring = ring.map(pointRadians), ring.pop(), ring;
    }

    function pointRadians(point) {
        return [point[0] * radians, point[1] * radians];
    }

    function contains(object, point) {
        return (object && containsObjectType.hasOwnProperty(object.type)
            ? containsObjectType[object.type]
            : containsGeometry)(object, point);
    }

    function graticuleX(y0, y1, dy) {
        var y = sequence(y0, y1 - epsilon$2, dy).concat(y1);
        return function(x) { return y.map(function(y) { return [x, y]; }); };
    }

    function graticuleY(x0, x1, dx) {
        var x = sequence(x0, x1 - epsilon$2, dx).concat(x1);
        return function(y) { return x.map(function(x) { return [x, y]; }); };
    }

    function graticule() {
        var x1, x0, X1, X0,
            y1, y0, Y1, Y0,
            dx = 10, dy = dx, DX = 90, DY = 360,
            x, y, X, Y,
            precision = 2.5;

        function graticule() {
            return {type: "MultiLineString", coordinates: lines()};
        }

        function lines() {
            return sequence(ceil(X0 / DX) * DX, X1, DX).map(X)
                .concat(sequence(ceil(Y0 / DY) * DY, Y1, DY).map(Y))
                .concat(sequence(ceil(x0 / dx) * dx, x1, dx).filter(function(x) { return abs(x % DX) > epsilon$2; }).map(x))
                .concat(sequence(ceil(y0 / dy) * dy, y1, dy).filter(function(y) { return abs(y % DY) > epsilon$2; }).map(y));
        }

        graticule.lines = function() {
            return lines().map(function(coordinates) { return {type: "LineString", coordinates: coordinates}; });
        };

        graticule.outline = function() {
            return {
                type: "Polygon",
                coordinates: [
                    X(X0).concat(
                        Y(Y1).slice(1),
                        X(X1).reverse().slice(1),
                        Y(Y0).reverse().slice(1))
                ]
            };
        };

        graticule.extent = function(_) {
            if (!arguments.length) return graticule.extentMinor();
            return graticule.extentMajor(_).extentMinor(_);
        };

        graticule.extentMajor = function(_) {
            if (!arguments.length) return [[X0, Y0], [X1, Y1]];
            X0 = +_[0][0], X1 = +_[1][0];
            Y0 = +_[0][1], Y1 = +_[1][1];
            if (X0 > X1) _ = X0, X0 = X1, X1 = _;
            if (Y0 > Y1) _ = Y0, Y0 = Y1, Y1 = _;
            return graticule.precision(precision);
        };

        graticule.extentMinor = function(_) {
            if (!arguments.length) return [[x0, y0], [x1, y1]];
            x0 = +_[0][0], x1 = +_[1][0];
            y0 = +_[0][1], y1 = +_[1][1];
            if (x0 > x1) _ = x0, x0 = x1, x1 = _;
            if (y0 > y1) _ = y0, y0 = y1, y1 = _;
            return graticule.precision(precision);
        };

        graticule.step = function(_) {
            if (!arguments.length) return graticule.stepMinor();
            return graticule.stepMajor(_).stepMinor(_);
        };

        graticule.stepMajor = function(_) {
            if (!arguments.length) return [DX, DY];
            DX = +_[0], DY = +_[1];
            return graticule;
        };

        graticule.stepMinor = function(_) {
            if (!arguments.length) return [dx, dy];
            dx = +_[0], dy = +_[1];
            return graticule;
        };

        graticule.precision = function(_) {
            if (!arguments.length) return precision;
            precision = +_;
            x = graticuleX(y0, y1, 90);
            y = graticuleY(x0, x1, precision);
            X = graticuleX(Y0, Y1, 90);
            Y = graticuleY(X0, X1, precision);
            return graticule;
        };

        return graticule
            .extentMajor([[-180, -90 + epsilon$2], [180, 90 - epsilon$2]])
            .extentMinor([[-180, -80 - epsilon$2], [180, 80 + epsilon$2]]);
    }

    function graticule10() {
        return graticule()();
    }

    function interpolate$1(a, b) {
        var x0 = a[0] * radians,
            y0 = a[1] * radians,
            x1 = b[0] * radians,
            y1 = b[1] * radians,
            cy0 = cos$1(y0),
            sy0 = sin$1(y0),
            cy1 = cos$1(y1),
            sy1 = sin$1(y1),
            kx0 = cy0 * cos$1(x0),
            ky0 = cy0 * sin$1(x0),
            kx1 = cy1 * cos$1(x1),
            ky1 = cy1 * sin$1(x1),
            d = 2 * asin(sqrt(haversin(y1 - y0) + cy0 * cy1 * haversin(x1 - x0))),
            k = sin$1(d);

        var interpolate = d ? function(t) {
            var B = sin$1(t *= d) / k,
                A = sin$1(d - t) / k,
                x = A * kx0 + B * kx1,
                y = A * ky0 + B * ky1,
                z = A * sy0 + B * sy1;
            return [
                atan2(y, x) * degrees$1,
                atan2(z, sqrt(x * x + y * y)) * degrees$1
            ];
        } : function() {
            return [x0 * degrees$1, y0 * degrees$1];
        };

        interpolate.distance = d;

        return interpolate;
    }

    function identity$4(x) {
        return x;
    }

    var areaSum$1 = adder();
    var areaRingSum$1 = adder();
    var x00;
    var y00;
    var x0$1;
    var y0$1;

    var areaStream$1 = {
        point: noop$1,
        lineStart: noop$1,
        lineEnd: noop$1,
        polygonStart: function() {
            areaStream$1.lineStart = areaRingStart$1;
            areaStream$1.lineEnd = areaRingEnd$1;
        },
        polygonEnd: function() {
            areaStream$1.lineStart = areaStream$1.lineEnd = areaStream$1.point = noop$1;
            areaSum$1.add(abs(areaRingSum$1));
            areaRingSum$1.reset();
        },
        result: function() {
            var area = areaSum$1 / 2;
            areaSum$1.reset();
            return area;
        }
    };

    function areaRingStart$1() {
        areaStream$1.point = areaPointFirst$1;
    }

    function areaPointFirst$1(x, y) {
        areaStream$1.point = areaPoint$1;
        x00 = x0$1 = x, y00 = y0$1 = y;
    }

    function areaPoint$1(x, y) {
        areaRingSum$1.add(y0$1 * x - x0$1 * y);
        x0$1 = x, y0$1 = y;
    }

    function areaRingEnd$1() {
        areaPoint$1(x00, y00);
    }

    var x0$2 = Infinity;
    var y0$2 = x0$2;
    var x1 = -x0$2;
    var y1 = x1;

    var boundsStream$1 = {
        point: boundsPoint$1,
        lineStart: noop$1,
        lineEnd: noop$1,
        polygonStart: noop$1,
        polygonEnd: noop$1,
        result: function() {
            var bounds = [[x0$2, y0$2], [x1, y1]];
            x1 = y1 = -(y0$2 = x0$2 = Infinity);
            return bounds;
        }
    };

    function boundsPoint$1(x, y) {
        if (x < x0$2) x0$2 = x;
        if (x > x1) x1 = x;
        if (y < y0$2) y0$2 = y;
        if (y > y1) y1 = y;
    }

// TODO Enforce positive area for exterior, negative area for interior?

    var X0$1 = 0;
    var Y0$1 = 0;
    var Z0$1 = 0;
    var X1$1 = 0;
    var Y1$1 = 0;
    var Z1$1 = 0;
    var X2$1 = 0;
    var Y2$1 = 0;
    var Z2$1 = 0;
    var x00$1;
    var y00$1;
    var x0$3;
    var y0$3;

    var centroidStream$1 = {
        point: centroidPoint$1,
        lineStart: centroidLineStart$1,
        lineEnd: centroidLineEnd$1,
        polygonStart: function() {
            centroidStream$1.lineStart = centroidRingStart$1;
            centroidStream$1.lineEnd = centroidRingEnd$1;
        },
        polygonEnd: function() {
            centroidStream$1.point = centroidPoint$1;
            centroidStream$1.lineStart = centroidLineStart$1;
            centroidStream$1.lineEnd = centroidLineEnd$1;
        },
        result: function() {
            var centroid = Z2$1 ? [X2$1 / Z2$1, Y2$1 / Z2$1]
                : Z1$1 ? [X1$1 / Z1$1, Y1$1 / Z1$1]
                    : Z0$1 ? [X0$1 / Z0$1, Y0$1 / Z0$1]
                        : [NaN, NaN];
            X0$1 = Y0$1 = Z0$1 =
                X1$1 = Y1$1 = Z1$1 =
                    X2$1 = Y2$1 = Z2$1 = 0;
            return centroid;
        }
    };

    function centroidPoint$1(x, y) {
        X0$1 += x;
        Y0$1 += y;
        ++Z0$1;
    }

    function centroidLineStart$1() {
        centroidStream$1.point = centroidPointFirstLine;
    }

    function centroidPointFirstLine(x, y) {
        centroidStream$1.point = centroidPointLine;
        centroidPoint$1(x0$3 = x, y0$3 = y);
    }

    function centroidPointLine(x, y) {
        var dx = x - x0$3, dy = y - y0$3, z = sqrt(dx * dx + dy * dy);
        X1$1 += z * (x0$3 + x) / 2;
        Y1$1 += z * (y0$3 + y) / 2;
        Z1$1 += z;
        centroidPoint$1(x0$3 = x, y0$3 = y);
    }

    function centroidLineEnd$1() {
        centroidStream$1.point = centroidPoint$1;
    }

    function centroidRingStart$1() {
        centroidStream$1.point = centroidPointFirstRing;
    }

    function centroidRingEnd$1() {
        centroidPointRing(x00$1, y00$1);
    }

    function centroidPointFirstRing(x, y) {
        centroidStream$1.point = centroidPointRing;
        centroidPoint$1(x00$1 = x0$3 = x, y00$1 = y0$3 = y);
    }

    function centroidPointRing(x, y) {
        var dx = x - x0$3,
            dy = y - y0$3,
            z = sqrt(dx * dx + dy * dy);

        X1$1 += z * (x0$3 + x) / 2;
        Y1$1 += z * (y0$3 + y) / 2;
        Z1$1 += z;

        z = y0$3 * x - x0$3 * y;
        X2$1 += z * (x0$3 + x);
        Y2$1 += z * (y0$3 + y);
        Z2$1 += z * 3;
        centroidPoint$1(x0$3 = x, y0$3 = y);
    }

    function PathContext(context) {
        this._context = context;
    }

    PathContext.prototype = {
        _radius: 4.5,
        pointRadius: function(_) {
            return this._radius = _, this;
        },
        polygonStart: function() {
            this._line = 0;
        },
        polygonEnd: function() {
            this._line = NaN;
        },
        lineStart: function() {
            this._point = 0;
        },
        lineEnd: function() {
            if (this._line === 0) this._context.closePath();
            this._point = NaN;
        },
        point: function(x, y) {
            switch (this._point) {
                case 0: {
                    this._context.moveTo(x, y);
                    this._point = 1;
                    break;
                }
                case 1: {
                    this._context.lineTo(x, y);
                    break;
                }
                default: {
                    this._context.moveTo(x + this._radius, y);
                    this._context.arc(x, y, this._radius, 0, tau$3);
                    break;
                }
            }
        },
        result: noop$1
    };

    var lengthSum$1 = adder();
    var lengthRing;
    var x00$2;
    var y00$2;
    var x0$4;
    var y0$4;

    var lengthStream$1 = {
        point: noop$1,
        lineStart: function() {
            lengthStream$1.point = lengthPointFirst$1;
        },
        lineEnd: function() {
            if (lengthRing) lengthPoint$1(x00$2, y00$2);
            lengthStream$1.point = noop$1;
        },
        polygonStart: function() {
            lengthRing = true;
        },
        polygonEnd: function() {
            lengthRing = null;
        },
        result: function() {
            var length = +lengthSum$1;
            lengthSum$1.reset();
            return length;
        }
    };

    function lengthPointFirst$1(x, y) {
        lengthStream$1.point = lengthPoint$1;
        x00$2 = x0$4 = x, y00$2 = y0$4 = y;
    }

    function lengthPoint$1(x, y) {
        x0$4 -= x, y0$4 -= y;
        lengthSum$1.add(sqrt(x0$4 * x0$4 + y0$4 * y0$4));
        x0$4 = x, y0$4 = y;
    }

    function PathString() {
        this._string = [];
    }

    PathString.prototype = {
        _radius: 4.5,
        _circle: circle$1(4.5),
        pointRadius: function(_) {
            if ((_ = +_) !== this._radius) this._radius = _, this._circle = null;
            return this;
        },
        polygonStart: function() {
            this._line = 0;
        },
        polygonEnd: function() {
            this._line = NaN;
        },
        lineStart: function() {
            this._point = 0;
        },
        lineEnd: function() {
            if (this._line === 0) this._string.push("Z");
            this._point = NaN;
        },
        point: function(x, y) {
            switch (this._point) {
                case 0: {
                    this._string.push("M", x, ",", y);
                    this._point = 1;
                    break;
                }
                case 1: {
                    this._string.push("L", x, ",", y);
                    break;
                }
                default: {
                    if (this._circle == null) this._circle = circle$1(this._radius);
                    this._string.push("M", x, ",", y, this._circle);
                    break;
                }
            }
        },
        result: function() {
            if (this._string.length) {
                var result = this._string.join("");
                this._string = [];
                return result;
            } else {
                return null;
            }
        }
    };

    function circle$1(radius) {
        return "m0," + radius
            + "a" + radius + "," + radius + " 0 1,1 0," + -2 * radius
            + "a" + radius + "," + radius + " 0 1,1 0," + 2 * radius
            + "z";
    }

    function index$1(projection, context) {
        var pointRadius = 4.5,
            projectionStream,
            contextStream;

        function path(object) {
            if (object) {
                if (typeof pointRadius === "function") contextStream.pointRadius(+pointRadius.apply(this, arguments));
                geoStream(object, projectionStream(contextStream));
            }
            return contextStream.result();
        }

        path.area = function(object) {
            geoStream(object, projectionStream(areaStream$1));
            return areaStream$1.result();
        };

        path.measure = function(object) {
            geoStream(object, projectionStream(lengthStream$1));
            return lengthStream$1.result();
        };

        path.bounds = function(object) {
            geoStream(object, projectionStream(boundsStream$1));
            return boundsStream$1.result();
        };

        path.centroid = function(object) {
            geoStream(object, projectionStream(centroidStream$1));
            return centroidStream$1.result();
        };

        path.projection = function(_) {
            return arguments.length ? (projectionStream = _ == null ? (projection = null, identity$4) : (projection = _).stream, path) : projection;
        };

        path.context = function(_) {
            if (!arguments.length) return context;
            contextStream = _ == null ? (context = null, new PathString) : new PathContext(context = _);
            if (typeof pointRadius !== "function") contextStream.pointRadius(pointRadius);
            return path;
        };

        path.pointRadius = function(_) {
            if (!arguments.length) return pointRadius;
            pointRadius = typeof _ === "function" ? _ : (contextStream.pointRadius(+_), +_);
            return path;
        };

        return path.projection(projection).context(context);
    }

    function transform(methods) {
        return {
            stream: transformer(methods)
        };
    }

    function transformer(methods) {
        return function(stream) {
            var s = new TransformStream;
            for (var key in methods) s[key] = methods[key];
            s.stream = stream;
            return s;
        };
    }

    function TransformStream() {}

    TransformStream.prototype = {
        constructor: TransformStream,
        point: function(x, y) { this.stream.point(x, y); },
        sphere: function() { this.stream.sphere(); },
        lineStart: function() { this.stream.lineStart(); },
        lineEnd: function() { this.stream.lineEnd(); },
        polygonStart: function() { this.stream.polygonStart(); },
        polygonEnd: function() { this.stream.polygonEnd(); }
    };

    function fit(projection, fitBounds, object) {
        var clip = projection.clipExtent && projection.clipExtent();
        projection.scale(150).translate([0, 0]);
        if (clip != null) projection.clipExtent(null);
        geoStream(object, projection.stream(boundsStream$1));
        fitBounds(boundsStream$1.result());
        if (clip != null) projection.clipExtent(clip);
        return projection;
    }

    function fitExtent(projection, extent, object) {
        return fit(projection, function(b) {
            var w = extent[1][0] - extent[0][0],
                h = extent[1][1] - extent[0][1],
                k = Math.min(w / (b[1][0] - b[0][0]), h / (b[1][1] - b[0][1])),
                x = +extent[0][0] + (w - k * (b[1][0] + b[0][0])) / 2,
                y = +extent[0][1] + (h - k * (b[1][1] + b[0][1])) / 2;
            projection.scale(150 * k).translate([x, y]);
        }, object);
    }

    function fitSize(projection, size, object) {
        return fitExtent(projection, [[0, 0], size], object);
    }

    function fitWidth(projection, width, object) {
        return fit(projection, function(b) {
            var w = +width,
                k = w / (b[1][0] - b[0][0]),
                x = (w - k * (b[1][0] + b[0][0])) / 2,
                y = -k * b[0][1];
            projection.scale(150 * k).translate([x, y]);
        }, object);
    }

    function fitHeight(projection, height, object) {
        return fit(projection, function(b) {
            var h = +height,
                k = h / (b[1][1] - b[0][1]),
                x = -k * b[0][0],
                y = (h - k * (b[1][1] + b[0][1])) / 2;
            projection.scale(150 * k).translate([x, y]);
        }, object);
    }

    var maxDepth = 16;
    var cosMinDistance = cos$1(30 * radians); // cos(minimum angular distance)

    function resample(project, delta2) {
        return +delta2 ? resample$1(project, delta2) : resampleNone(project);
    }

    function resampleNone(project) {
        return transformer({
            point: function(x, y) {
                x = project(x, y);
                this.stream.point(x[0], x[1]);
            }
        });
    }

    function resample$1(project, delta2) {

        function resampleLineTo(x0, y0, lambda0, a0, b0, c0, x1, y1, lambda1, a1, b1, c1, depth, stream) {
            var dx = x1 - x0,
                dy = y1 - y0,
                d2 = dx * dx + dy * dy;
            if (d2 > 4 * delta2 && depth--) {
                var a = a0 + a1,
                    b = b0 + b1,
                    c = c0 + c1,
                    m = sqrt(a * a + b * b + c * c),
                    phi2 = asin(c /= m),
                    lambda2 = abs(abs(c) - 1) < epsilon$2 || abs(lambda0 - lambda1) < epsilon$2 ? (lambda0 + lambda1) / 2 : atan2(b, a),
                    p = project(lambda2, phi2),
                    x2 = p[0],
                    y2 = p[1],
                    dx2 = x2 - x0,
                    dy2 = y2 - y0,
                    dz = dy * dx2 - dx * dy2;
                if (dz * dz / d2 > delta2 // perpendicular projected distance
                    || abs((dx * dx2 + dy * dy2) / d2 - 0.5) > 0.3 // midpoint close to an end
                    || a0 * a1 + b0 * b1 + c0 * c1 < cosMinDistance) { // angular distance
                    resampleLineTo(x0, y0, lambda0, a0, b0, c0, x2, y2, lambda2, a /= m, b /= m, c, depth, stream);
                    stream.point(x2, y2);
                    resampleLineTo(x2, y2, lambda2, a, b, c, x1, y1, lambda1, a1, b1, c1, depth, stream);
                }
            }
        }
        return function(stream) {
            var lambda00, x00, y00, a00, b00, c00, // first point
                lambda0, x0, y0, a0, b0, c0; // previous point

            var resampleStream = {
                point: point,
                lineStart: lineStart,
                lineEnd: lineEnd,
                polygonStart: function() { stream.polygonStart(); resampleStream.lineStart = ringStart; },
                polygonEnd: function() { stream.polygonEnd(); resampleStream.lineStart = lineStart; }
            };

            function point(x, y) {
                x = project(x, y);
                stream.point(x[0], x[1]);
            }

            function lineStart() {
                x0 = NaN;
                resampleStream.point = linePoint;
                stream.lineStart();
            }

            function linePoint(lambda, phi) {
                var c = cartesian([lambda, phi]), p = project(lambda, phi);
                resampleLineTo(x0, y0, lambda0, a0, b0, c0, x0 = p[0], y0 = p[1], lambda0 = lambda, a0 = c[0], b0 = c[1], c0 = c[2], maxDepth, stream);
                stream.point(x0, y0);
            }

            function lineEnd() {
                resampleStream.point = point;
                stream.lineEnd();
            }

            function ringStart() {
                lineStart();
                resampleStream.point = ringPoint;
                resampleStream.lineEnd = ringEnd;
            }

            function ringPoint(lambda, phi) {
                linePoint(lambda00 = lambda, phi), x00 = x0, y00 = y0, a00 = a0, b00 = b0, c00 = c0;
                resampleStream.point = linePoint;
            }

            function ringEnd() {
                resampleLineTo(x0, y0, lambda0, a0, b0, c0, x00, y00, lambda00, a00, b00, c00, maxDepth, stream);
                resampleStream.lineEnd = lineEnd;
                lineEnd();
            }

            return resampleStream;
        };
    }

    var transformRadians = transformer({
        point: function(x, y) {
            this.stream.point(x * radians, y * radians);
        }
    });

    function transformRotate(rotate) {
        return transformer({
            point: function(x, y) {
                var r = rotate(x, y);
                return this.stream.point(r[0], r[1]);
            }
        });
    }

    function projection(project) {
        return projectionMutator(function() { return project; })();
    }

    function projectionMutator(projectAt) {
        var project,
            k = 150, // scale
            x = 480, y = 250, // translate
            dx, dy, lambda = 0, phi = 0, // center
            deltaLambda = 0, deltaPhi = 0, deltaGamma = 0, rotate, projectRotate, // rotate
            theta = null, preclip = clipAntimeridian, // clip angle
            x0 = null, y0, x1, y1, postclip = identity$4, // clip extent
            delta2 = 0.5, projectResample = resample(projectTransform, delta2), // precision
            cache,
            cacheStream;

        function projection(point) {
            point = projectRotate(point[0] * radians, point[1] * radians);
            return [point[0] * k + dx, dy - point[1] * k];
        }

        function invert(point) {
            point = projectRotate.invert((point[0] - dx) / k, (dy - point[1]) / k);
            return point && [point[0] * degrees$1, point[1] * degrees$1];
        }

        function projectTransform(x, y) {
            return x = project(x, y), [x[0] * k + dx, dy - x[1] * k];
        }

        projection.stream = function(stream) {
            return cache && cacheStream === stream ? cache : cache = transformRadians(transformRotate(rotate)(preclip(projectResample(postclip(cacheStream = stream)))));
        };

        projection.preclip = function(_) {
            return arguments.length ? (preclip = _, theta = undefined, reset()) : preclip;
        };

        projection.postclip = function(_) {
            return arguments.length ? (postclip = _, x0 = y0 = x1 = y1 = null, reset()) : postclip;
        };

        projection.clipAngle = function(_) {
            return arguments.length ? (preclip = +_ ? clipCircle(theta = _ * radians) : (theta = null, clipAntimeridian), reset()) : theta * degrees$1;
        };

        projection.clipExtent = function(_) {
            return arguments.length ? (postclip = _ == null ? (x0 = y0 = x1 = y1 = null, identity$4) : clipRectangle(x0 = +_[0][0], y0 = +_[0][1], x1 = +_[1][0], y1 = +_[1][1]), reset()) : x0 == null ? null : [[x0, y0], [x1, y1]];
        };

        projection.scale = function(_) {
            return arguments.length ? (k = +_, recenter()) : k;
        };

        projection.translate = function(_) {
            return arguments.length ? (x = +_[0], y = +_[1], recenter()) : [x, y];
        };

        projection.center = function(_) {
            return arguments.length ? (lambda = _[0] % 360 * radians, phi = _[1] % 360 * radians, recenter()) : [lambda * degrees$1, phi * degrees$1];
        };

        projection.rotate = function(_) {
            return arguments.length ? (deltaLambda = _[0] % 360 * radians, deltaPhi = _[1] % 360 * radians, deltaGamma = _.length > 2 ? _[2] % 360 * radians : 0, recenter()) : [deltaLambda * degrees$1, deltaPhi * degrees$1, deltaGamma * degrees$1];
        };

        projection.precision = function(_) {
            return arguments.length ? (projectResample = resample(projectTransform, delta2 = _ * _), reset()) : sqrt(delta2);
        };

        projection.fitExtent = function(extent, object) {
            return fitExtent(projection, extent, object);
        };

        projection.fitSize = function(size, object) {
            return fitSize(projection, size, object);
        };

        projection.fitWidth = function(width, object) {
            return fitWidth(projection, width, object);
        };

        projection.fitHeight = function(height, object) {
            return fitHeight(projection, height, object);
        };

        function recenter() {
            projectRotate = compose(rotate = rotateRadians(deltaLambda, deltaPhi, deltaGamma), project);
            var center = project(lambda, phi);
            dx = x - center[0] * k;
            dy = y + center[1] * k;
            return reset();
        }

        function reset() {
            cache = cacheStream = null;
            return projection;
        }

        return function() {
            project = projectAt.apply(this, arguments);
            projection.invert = project.invert && invert;
            return recenter();
        };
    }

    function conicProjection(projectAt) {
        var phi0 = 0,
            phi1 = pi$3 / 3,
            m = projectionMutator(projectAt),
            p = m(phi0, phi1);

        p.parallels = function(_) {
            return arguments.length ? m(phi0 = _[0] * radians, phi1 = _[1] * radians) : [phi0 * degrees$1, phi1 * degrees$1];
        };

        return p;
    }

    function cylindricalEqualAreaRaw(phi0) {
        var cosPhi0 = cos$1(phi0);

        function forward(lambda, phi) {
            return [lambda * cosPhi0, sin$1(phi) / cosPhi0];
        }

        forward.invert = function(x, y) {
            return [x / cosPhi0, asin(y * cosPhi0)];
        };

        return forward;
    }

    function conicEqualAreaRaw(y0, y1) {
        var sy0 = sin$1(y0), n = (sy0 + sin$1(y1)) / 2;

        // Are the parallels symmetrical around the Equator?
        if (abs(n) < epsilon$2) return cylindricalEqualAreaRaw(y0);

        var c = 1 + sy0 * (2 * n - sy0), r0 = sqrt(c) / n;

        function project(x, y) {
            var r = sqrt(c - 2 * n * sin$1(y)) / n;
            return [r * sin$1(x *= n), r0 - r * cos$1(x)];
        }

        project.invert = function(x, y) {
            var r0y = r0 - y;
            return [atan2(x, abs(r0y)) / n * sign(r0y), asin((c - (x * x + r0y * r0y) * n * n) / (2 * n))];
        };

        return project;
    }

    function conicEqualArea() {
        return conicProjection(conicEqualAreaRaw)
            .scale(155.424)
            .center([0, 33.6442]);
    }

    function albers() {
        return conicEqualArea()
            .parallels([29.5, 45.5])
            .scale(1070)
            .translate([480, 250])
            .rotate([96, 0])
            .center([-0.6, 38.7]);
    }

// The projections must have mutually exclusive clip regions on the sphere,
// as this will avoid emitting interleaving lines and polygons.
    function multiplex(streams) {
        var n = streams.length;
        return {
            point: function(x, y) { var i = -1; while (++i < n) streams[i].point(x, y); },
            sphere: function() { var i = -1; while (++i < n) streams[i].sphere(); },
            lineStart: function() { var i = -1; while (++i < n) streams[i].lineStart(); },
            lineEnd: function() { var i = -1; while (++i < n) streams[i].lineEnd(); },
            polygonStart: function() { var i = -1; while (++i < n) streams[i].polygonStart(); },
            polygonEnd: function() { var i = -1; while (++i < n) streams[i].polygonEnd(); }
        };
    }

// A composite projection for the United States, configured by default for
// 960×500. The projection also works quite well at 960×600 if you change the
// scale to 1285 and adjust the translate accordingly. The set of standard
// parallels for each region comes from USGS, which is published here:
// http://egsc.usgs.gov/isb/pubs/MapProjections/projections.html#albers
    function albersUsa() {
        var cache,
            cacheStream,
            lower48 = albers(), lower48Point,
            alaska = conicEqualArea().rotate([154, 0]).center([-2, 58.5]).parallels([55, 65]), alaskaPoint, // EPSG:3338
            hawaii = conicEqualArea().rotate([157, 0]).center([-3, 19.9]).parallels([8, 18]), hawaiiPoint, // ESRI:102007
            point, pointStream = {point: function(x, y) { point = [x, y]; }};

        function albersUsa(coordinates) {
            var x = coordinates[0], y = coordinates[1];
            return point = null, (lower48Point.point(x, y), point)
            || (alaskaPoint.point(x, y), point)
            || (hawaiiPoint.point(x, y), point);
        }

        albersUsa.invert = function(coordinates) {
            var k = lower48.scale(),
                t = lower48.translate(),
                x = (coordinates[0] - t[0]) / k,
                y = (coordinates[1] - t[1]) / k;
            return (y >= 0.120 && y < 0.234 && x >= -0.425 && x < -0.214 ? alaska
                : y >= 0.166 && y < 0.234 && x >= -0.214 && x < -0.115 ? hawaii
                    : lower48).invert(coordinates);
        };

        albersUsa.stream = function(stream) {
            return cache && cacheStream === stream ? cache : cache = multiplex([lower48.stream(cacheStream = stream), alaska.stream(stream), hawaii.stream(stream)]);
        };

        albersUsa.precision = function(_) {
            if (!arguments.length) return lower48.precision();
            lower48.precision(_), alaska.precision(_), hawaii.precision(_);
            return reset();
        };

        albersUsa.scale = function(_) {
            if (!arguments.length) return lower48.scale();
            lower48.scale(_), alaska.scale(_ * 0.35), hawaii.scale(_);
            return albersUsa.translate(lower48.translate());
        };

        albersUsa.translate = function(_) {
            if (!arguments.length) return lower48.translate();
            var k = lower48.scale(), x = +_[0], y = +_[1];

            lower48Point = lower48
                .translate(_)
                .clipExtent([[x - 0.455 * k, y - 0.238 * k], [x + 0.455 * k, y + 0.238 * k]])
                .stream(pointStream);

            alaskaPoint = alaska
                .translate([x - 0.307 * k, y + 0.201 * k])
                .clipExtent([[x - 0.425 * k + epsilon$2, y + 0.120 * k + epsilon$2], [x - 0.214 * k - epsilon$2, y + 0.234 * k - epsilon$2]])
                .stream(pointStream);

            hawaiiPoint = hawaii
                .translate([x - 0.205 * k, y + 0.212 * k])
                .clipExtent([[x - 0.214 * k + epsilon$2, y + 0.166 * k + epsilon$2], [x - 0.115 * k - epsilon$2, y + 0.234 * k - epsilon$2]])
                .stream(pointStream);

            return reset();
        };

        albersUsa.fitExtent = function(extent, object) {
            return fitExtent(albersUsa, extent, object);
        };

        albersUsa.fitSize = function(size, object) {
            return fitSize(albersUsa, size, object);
        };

        albersUsa.fitWidth = function(width, object) {
            return fitWidth(albersUsa, width, object);
        };

        albersUsa.fitHeight = function(height, object) {
            return fitHeight(albersUsa, height, object);
        };

        function reset() {
            cache = cacheStream = null;
            return albersUsa;
        }

        return albersUsa.scale(1070);
    }

    function azimuthalRaw(scale) {
        return function(x, y) {
            var cx = cos$1(x),
                cy = cos$1(y),
                k = scale(cx * cy);
            return [
                k * cy * sin$1(x),
                k * sin$1(y)
            ];
        }
    }

    function azimuthalInvert(angle) {
        return function(x, y) {
            var z = sqrt(x * x + y * y),
                c = angle(z),
                sc = sin$1(c),
                cc = cos$1(c);
            return [
                atan2(x * sc, z * cc),
                asin(z && y * sc / z)
            ];
        }
    }

    var azimuthalEqualAreaRaw = azimuthalRaw(function(cxcy) {
        return sqrt(2 / (1 + cxcy));
    });

    azimuthalEqualAreaRaw.invert = azimuthalInvert(function(z) {
        return 2 * asin(z / 2);
    });

    function azimuthalEqualArea() {
        return projection(azimuthalEqualAreaRaw)
            .scale(124.75)
            .clipAngle(180 - 1e-3);
    }

    var azimuthalEquidistantRaw = azimuthalRaw(function(c) {
        return (c = acos(c)) && c / sin$1(c);
    });

    azimuthalEquidistantRaw.invert = azimuthalInvert(function(z) {
        return z;
    });

    function azimuthalEquidistant() {
        return projection(azimuthalEquidistantRaw)
            .scale(79.4188)
            .clipAngle(180 - 1e-3);
    }

    function mercatorRaw(lambda, phi) {
        return [lambda, log(tan((halfPi$2 + phi) / 2))];
    }

    mercatorRaw.invert = function(x, y) {
        return [x, 2 * atan(exp(y)) - halfPi$2];
    };

    function mercator() {
        return mercatorProjection(mercatorRaw)
            .scale(961 / tau$3);
    }

    function mercatorProjection(project) {
        var m = projection(project),
            center = m.center,
            scale = m.scale,
            translate = m.translate,
            clipExtent = m.clipExtent,
            x0 = null, y0, x1, y1; // clip extent

        m.scale = function(_) {
            return arguments.length ? (scale(_), reclip()) : scale();
        };

        m.translate = function(_) {
            return arguments.length ? (translate(_), reclip()) : translate();
        };

        m.center = function(_) {
            return arguments.length ? (center(_), reclip()) : center();
        };

        m.clipExtent = function(_) {
            return arguments.length ? (_ == null ? x0 = y0 = x1 = y1 = null : (x0 = +_[0][0], y0 = +_[0][1], x1 = +_[1][0], y1 = +_[1][1]), reclip()) : x0 == null ? null : [[x0, y0], [x1, y1]];
        };

        function reclip() {
            var k = pi$3 * scale(),
                t = m(rotation(m.rotate()).invert([0, 0]));
            return clipExtent(x0 == null
                ? [[t[0] - k, t[1] - k], [t[0] + k, t[1] + k]] : project === mercatorRaw
                    ? [[Math.max(t[0] - k, x0), y0], [Math.min(t[0] + k, x1), y1]]
                    : [[x0, Math.max(t[1] - k, y0)], [x1, Math.min(t[1] + k, y1)]]);
        }

        return reclip();
    }

    function tany(y) {
        return tan((halfPi$2 + y) / 2);
    }

    function conicConformalRaw(y0, y1) {
        var cy0 = cos$1(y0),
            n = y0 === y1 ? sin$1(y0) : log(cy0 / cos$1(y1)) / log(tany(y1) / tany(y0)),
            f = cy0 * pow(tany(y0), n) / n;

        if (!n) return mercatorRaw;

        function project(x, y) {
            if (f > 0) { if (y < -halfPi$2 + epsilon$2) y = -halfPi$2 + epsilon$2; }
            else { if (y > halfPi$2 - epsilon$2) y = halfPi$2 - epsilon$2; }
            var r = f / pow(tany(y), n);
            return [r * sin$1(n * x), f - r * cos$1(n * x)];
        }

        project.invert = function(x, y) {
            var fy = f - y, r = sign(n) * sqrt(x * x + fy * fy);
            return [atan2(x, abs(fy)) / n * sign(fy), 2 * atan(pow(f / r, 1 / n)) - halfPi$2];
        };

        return project;
    }

    function conicConformal() {
        return conicProjection(conicConformalRaw)
            .scale(109.5)
            .parallels([30, 30]);
    }

    function equirectangularRaw(lambda, phi) {
        return [lambda, phi];
    }

    equirectangularRaw.invert = equirectangularRaw;

    function equirectangular() {
        return projection(equirectangularRaw)
            .scale(152.63);
    }

    function conicEquidistantRaw(y0, y1) {
        var cy0 = cos$1(y0),
            n = y0 === y1 ? sin$1(y0) : (cy0 - cos$1(y1)) / (y1 - y0),
            g = cy0 / n + y0;

        if (abs(n) < epsilon$2) return equirectangularRaw;

        function project(x, y) {
            var gy = g - y, nx = n * x;
            return [gy * sin$1(nx), g - gy * cos$1(nx)];
        }

        project.invert = function(x, y) {
            var gy = g - y;
            return [atan2(x, abs(gy)) / n * sign(gy), g - sign(n) * sqrt(x * x + gy * gy)];
        };

        return project;
    }

    function conicEquidistant() {
        return conicProjection(conicEquidistantRaw)
            .scale(131.154)
            .center([0, 13.9389]);
    }

    function gnomonicRaw(x, y) {
        var cy = cos$1(y), k = cos$1(x) * cy;
        return [cy * sin$1(x) / k, sin$1(y) / k];
    }

    gnomonicRaw.invert = azimuthalInvert(atan);

    function gnomonic() {
        return projection(gnomonicRaw)
            .scale(144.049)
            .clipAngle(60);
    }

    function scaleTranslate(kx, ky, tx, ty) {
        return kx === 1 && ky === 1 && tx === 0 && ty === 0 ? identity$4 : transformer({
            point: function(x, y) {
                this.stream.point(x * kx + tx, y * ky + ty);
            }
        });
    }

    function identity$5() {
        var k = 1, tx = 0, ty = 0, sx = 1, sy = 1, transform$$1 = identity$4, // scale, translate and reflect
            x0 = null, y0, x1, y1, // clip extent
            postclip = identity$4,
            cache,
            cacheStream,
            projection;

        function reset() {
            cache = cacheStream = null;
            return projection;
        }

        return projection = {
            stream: function(stream) {
                return cache && cacheStream === stream ? cache : cache = transform$$1(postclip(cacheStream = stream));
            },
            postclip: function(_) {
                return arguments.length ? (postclip = _, x0 = y0 = x1 = y1 = null, reset()) : postclip;
            },
            clipExtent: function(_) {
                return arguments.length ? (postclip = _ == null ? (x0 = y0 = x1 = y1 = null, identity$4) : clipRectangle(x0 = +_[0][0], y0 = +_[0][1], x1 = +_[1][0], y1 = +_[1][1]), reset()) : x0 == null ? null : [[x0, y0], [x1, y1]];
            },
            scale: function(_) {
                return arguments.length ? (transform$$1 = scaleTranslate((k = +_) * sx, k * sy, tx, ty), reset()) : k;
            },
            translate: function(_) {
                return arguments.length ? (transform$$1 = scaleTranslate(k * sx, k * sy, tx = +_[0], ty = +_[1]), reset()) : [tx, ty];
            },
            reflectX: function(_) {
                return arguments.length ? (transform$$1 = scaleTranslate(k * (sx = _ ? -1 : 1), k * sy, tx, ty), reset()) : sx < 0;
            },
            reflectY: function(_) {
                return arguments.length ? (transform$$1 = scaleTranslate(k * sx, k * (sy = _ ? -1 : 1), tx, ty), reset()) : sy < 0;
            },
            fitExtent: function(extent, object) {
                return fitExtent(projection, extent, object);
            },
            fitSize: function(size, object) {
                return fitSize(projection, size, object);
            },
            fitWidth: function(width, object) {
                return fitWidth(projection, width, object);
            },
            fitHeight: function(height, object) {
                return fitHeight(projection, height, object);
            }
        };
    }

    function naturalEarth1Raw(lambda, phi) {
        var phi2 = phi * phi, phi4 = phi2 * phi2;
        return [
            lambda * (0.8707 - 0.131979 * phi2 + phi4 * (-0.013791 + phi4 * (0.003971 * phi2 - 0.001529 * phi4))),
            phi * (1.007226 + phi2 * (0.015085 + phi4 * (-0.044475 + 0.028874 * phi2 - 0.005916 * phi4)))
        ];
    }

    naturalEarth1Raw.invert = function(x, y) {
        var phi = y, i = 25, delta;
        do {
            var phi2 = phi * phi, phi4 = phi2 * phi2;
            phi -= delta = (phi * (1.007226 + phi2 * (0.015085 + phi4 * (-0.044475 + 0.028874 * phi2 - 0.005916 * phi4))) - y) /
                (1.007226 + phi2 * (0.015085 * 3 + phi4 * (-0.044475 * 7 + 0.028874 * 9 * phi2 - 0.005916 * 11 * phi4)));
        } while (abs(delta) > epsilon$2 && --i > 0);
        return [
            x / (0.8707 + (phi2 = phi * phi) * (-0.131979 + phi2 * (-0.013791 + phi2 * phi2 * phi2 * (0.003971 - 0.001529 * phi2)))),
            phi
        ];
    };

    function naturalEarth1() {
        return projection(naturalEarth1Raw)
            .scale(175.295);
    }

    function orthographicRaw(x, y) {
        return [cos$1(y) * sin$1(x), sin$1(y)];
    }

    orthographicRaw.invert = azimuthalInvert(asin);

    function orthographic() {
        return projection(orthographicRaw)
            .scale(249.5)
            .clipAngle(90 + epsilon$2);
    }

    function stereographicRaw(x, y) {
        var cy = cos$1(y), k = 1 + cos$1(x) * cy;
        return [cy * sin$1(x) / k, sin$1(y) / k];
    }

    stereographicRaw.invert = azimuthalInvert(function(z) {
        return 2 * atan(z);
    });

    function stereographic() {
        return projection(stereographicRaw)
            .scale(250)
            .clipAngle(142);
    }

    function transverseMercatorRaw(lambda, phi) {
        return [log(tan((halfPi$2 + phi) / 2)), -lambda];
    }

    transverseMercatorRaw.invert = function(x, y) {
        return [-y, 2 * atan(exp(x)) - halfPi$2];
    };

    function transverseMercator() {
        var m = mercatorProjection(transverseMercatorRaw),
            center = m.center,
            rotate = m.rotate;

        m.center = function(_) {
            return arguments.length ? center([-_[1], _[0]]) : (_ = center(), [_[1], -_[0]]);
        };

        m.rotate = function(_) {
            return arguments.length ? rotate([_[0], _[1], _.length > 2 ? _[2] + 90 : 90]) : (_ = rotate(), [_[0], _[1], _[2] - 90]);
        };

        return rotate([0, 0, 90])
            .scale(159.155);
    }

    function defaultSeparation(a, b) {
        return a.parent === b.parent ? 1 : 2;
    }

    function meanX(children) {
        return children.reduce(meanXReduce, 0) / children.length;
    }

    function meanXReduce(x, c) {
        return x + c.x;
    }

    function maxY(children) {
        return 1 + children.reduce(maxYReduce, 0);
    }

    function maxYReduce(y, c) {
        return Math.max(y, c.y);
    }

    function leafLeft(node) {
        var children;
        while (children = node.children) node = children[0];
        return node;
    }

    function leafRight(node) {
        var children;
        while (children = node.children) node = children[children.length - 1];
        return node;
    }

    function cluster() {
        var separation = defaultSeparation,
            dx = 1,
            dy = 1,
            nodeSize = false;

        function cluster(root) {
            var previousNode,
                x = 0;

            // First walk, computing the initial x & y values.
            root.eachAfter(function(node) {
                var children = node.children;
                if (children) {
                    node.x = meanX(children);
                    node.y = maxY(children);
                } else {
                    node.x = previousNode ? x += separation(node, previousNode) : 0;
                    node.y = 0;
                    previousNode = node;
                }
            });

            var left = leafLeft(root),
                right = leafRight(root),
                x0 = left.x - separation(left, right) / 2,
                x1 = right.x + separation(right, left) / 2;

            // Second walk, normalizing x & y to the desired size.
            return root.eachAfter(nodeSize ? function(node) {
                node.x = (node.x - root.x) * dx;
                node.y = (root.y - node.y) * dy;
            } : function(node) {
                node.x = (node.x - x0) / (x1 - x0) * dx;
                node.y = (1 - (root.y ? node.y / root.y : 1)) * dy;
            });
        }

        cluster.separation = function(x) {
            return arguments.length ? (separation = x, cluster) : separation;
        };

        cluster.size = function(x) {
            return arguments.length ? (nodeSize = false, dx = +x[0], dy = +x[1], cluster) : (nodeSize ? null : [dx, dy]);
        };

        cluster.nodeSize = function(x) {
            return arguments.length ? (nodeSize = true, dx = +x[0], dy = +x[1], cluster) : (nodeSize ? [dx, dy] : null);
        };

        return cluster;
    }

    function count(node) {
        var sum = 0,
            children = node.children,
            i = children && children.length;
        if (!i) sum = 1;
        else while (--i >= 0) sum += children[i].value;
        node.value = sum;
    }

    function node_count() {
        return this.eachAfter(count);
    }

    function node_each(callback) {
        var node = this, current, next = [node], children, i, n;
        do {
            current = next.reverse(), next = [];
            while (node = current.pop()) {
                callback(node), children = node.children;
                if (children) for (i = 0, n = children.length; i < n; ++i) {
                    next.push(children[i]);
                }
            }
        } while (next.length);
        return this;
    }

    function node_eachBefore(callback) {
        var node = this, nodes = [node], children, i;
        while (node = nodes.pop()) {
            callback(node), children = node.children;
            if (children) for (i = children.length - 1; i >= 0; --i) {
                nodes.push(children[i]);
            }
        }
        return this;
    }

    function node_eachAfter(callback) {
        var node = this, nodes = [node], next = [], children, i, n;
        while (node = nodes.pop()) {
            next.push(node), children = node.children;
            if (children) for (i = 0, n = children.length; i < n; ++i) {
                nodes.push(children[i]);
            }
        }
        while (node = next.pop()) {
            callback(node);
        }
        return this;
    }

    function node_sum(value) {
        return this.eachAfter(function(node) {
            var sum = +value(node.data) || 0,
                children = node.children,
                i = children && children.length;
            while (--i >= 0) sum += children[i].value;
            node.value = sum;
        });
    }

    function node_sort(compare) {
        return this.eachBefore(function(node) {
            if (node.children) {
                node.children.sort(compare);
            }
        });
    }

    function node_path(end) {
        var start = this,
            ancestor = leastCommonAncestor(start, end),
            nodes = [start];
        while (start !== ancestor) {
            start = start.parent;
            nodes.push(start);
        }
        var k = nodes.length;
        while (end !== ancestor) {
            nodes.splice(k, 0, end);
            end = end.parent;
        }
        return nodes;
    }

    function leastCommonAncestor(a, b) {
        if (a === b) return a;
        var aNodes = a.ancestors(),
            bNodes = b.ancestors(),
            c = null;
        a = aNodes.pop();
        b = bNodes.pop();
        while (a === b) {
            c = a;
            a = aNodes.pop();
            b = bNodes.pop();
        }
        return c;
    }

    function node_ancestors() {
        var node = this, nodes = [node];
        while (node = node.parent) {
            nodes.push(node);
        }
        return nodes;
    }

    function node_descendants() {
        var nodes = [];
        this.each(function(node) {
            nodes.push(node);
        });
        return nodes;
    }

    function node_leaves() {
        var leaves = [];
        this.eachBefore(function(node) {
            if (!node.children) {
                leaves.push(node);
            }
        });
        return leaves;
    }

    function node_links() {
        var root = this, links = [];
        root.each(function(node) {
            if (node !== root) { // Don’t include the root’s parent, if any.
                links.push({source: node.parent, target: node});
            }
        });
        return links;
    }

    function hierarchy(data, children) {
        var root = new Node(data),
            valued = +data.value && (root.value = data.value),
            node,
            nodes = [root],
            child,
            childs,
            i,
            n;

        if (children == null) children = defaultChildren;

        while (node = nodes.pop()) {
            if (valued) node.value = +node.data.value;
            if ((childs = children(node.data)) && (n = childs.length)) {
                node.children = new Array(n);
                for (i = n - 1; i >= 0; --i) {
                    nodes.push(child = node.children[i] = new Node(childs[i]));
                    child.parent = node;
                    child.depth = node.depth + 1;
                }
            }
        }

        return root.eachBefore(computeHeight);
    }

    function node_copy() {
        return hierarchy(this).eachBefore(copyData);
    }

    function defaultChildren(d) {
        return d.children;
    }

    function copyData(node) {
        node.data = node.data.data;
    }

    function computeHeight(node) {
        var height = 0;
        do node.height = height;
        while ((node = node.parent) && (node.height < ++height));
    }

    function Node(data) {
        this.data = data;
        this.depth =
            this.height = 0;
        this.parent = null;
    }

    Node.prototype = hierarchy.prototype = {
        constructor: Node,
        count: node_count,
        each: node_each,
        eachAfter: node_eachAfter,
        eachBefore: node_eachBefore,
        sum: node_sum,
        sort: node_sort,
        path: node_path,
        ancestors: node_ancestors,
        descendants: node_descendants,
        leaves: node_leaves,
        links: node_links,
        copy: node_copy
    };

    var slice$3 = Array.prototype.slice;

    function shuffle$1(array) {
        var m = array.length,
            t,
            i;

        while (m) {
            i = Math.random() * m-- | 0;
            t = array[m];
            array[m] = array[i];
            array[i] = t;
        }

        return array;
    }

    function enclose(circles) {
        var i = 0, n = (circles = shuffle$1(slice$3.call(circles))).length, B = [], p, e;

        while (i < n) {
            p = circles[i];
            if (e && enclosesWeak(e, p)) ++i;
            else e = encloseBasis(B = extendBasis(B, p)), i = 0;
        }

        return e;
    }

    function extendBasis(B, p) {
        var i, j;

        if (enclosesWeakAll(p, B)) return [p];

        // If we get here then B must have at least one element.
        for (i = 0; i < B.length; ++i) {
            if (enclosesNot(p, B[i])
                && enclosesWeakAll(encloseBasis2(B[i], p), B)) {
                return [B[i], p];
            }
        }

        // If we get here then B must have at least two elements.
        for (i = 0; i < B.length - 1; ++i) {
            for (j = i + 1; j < B.length; ++j) {
                if (enclosesNot(encloseBasis2(B[i], B[j]), p)
                    && enclosesNot(encloseBasis2(B[i], p), B[j])
                    && enclosesNot(encloseBasis2(B[j], p), B[i])
                    && enclosesWeakAll(encloseBasis3(B[i], B[j], p), B)) {
                    return [B[i], B[j], p];
                }
            }
        }

        // If we get here then something is very wrong.
        throw new Error;
    }

    function enclosesNot(a, b) {
        var dr = a.r - b.r, dx = b.x - a.x, dy = b.y - a.y;
        return dr < 0 || dr * dr < dx * dx + dy * dy;
    }

    function enclosesWeak(a, b) {
        var dr = a.r - b.r + 1e-6, dx = b.x - a.x, dy = b.y - a.y;
        return dr > 0 && dr * dr > dx * dx + dy * dy;
    }

    function enclosesWeakAll(a, B) {
        for (var i = 0; i < B.length; ++i) {
            if (!enclosesWeak(a, B[i])) {
                return false;
            }
        }
        return true;
    }

    function encloseBasis(B) {
        switch (B.length) {
            case 1: return encloseBasis1(B[0]);
            case 2: return encloseBasis2(B[0], B[1]);
            case 3: return encloseBasis3(B[0], B[1], B[2]);
        }
    }

    function encloseBasis1(a) {
        return {
            x: a.x,
            y: a.y,
            r: a.r
        };
    }

    function encloseBasis2(a, b) {
        var x1 = a.x, y1 = a.y, r1 = a.r,
            x2 = b.x, y2 = b.y, r2 = b.r,
            x21 = x2 - x1, y21 = y2 - y1, r21 = r2 - r1,
            l = Math.sqrt(x21 * x21 + y21 * y21);
        return {
            x: (x1 + x2 + x21 / l * r21) / 2,
            y: (y1 + y2 + y21 / l * r21) / 2,
            r: (l + r1 + r2) / 2
        };
    }

    function encloseBasis3(a, b, c) {
        var x1 = a.x, y1 = a.y, r1 = a.r,
            x2 = b.x, y2 = b.y, r2 = b.r,
            x3 = c.x, y3 = c.y, r3 = c.r,
            a2 = x1 - x2,
            a3 = x1 - x3,
            b2 = y1 - y2,
            b3 = y1 - y3,
            c2 = r2 - r1,
            c3 = r3 - r1,
            d1 = x1 * x1 + y1 * y1 - r1 * r1,
            d2 = d1 - x2 * x2 - y2 * y2 + r2 * r2,
            d3 = d1 - x3 * x3 - y3 * y3 + r3 * r3,
            ab = a3 * b2 - a2 * b3,
            xa = (b2 * d3 - b3 * d2) / (ab * 2) - x1,
            xb = (b3 * c2 - b2 * c3) / ab,
            ya = (a3 * d2 - a2 * d3) / (ab * 2) - y1,
            yb = (a2 * c3 - a3 * c2) / ab,
            A = xb * xb + yb * yb - 1,
            B = 2 * (r1 + xa * xb + ya * yb),
            C = xa * xa + ya * ya - r1 * r1,
            r = -(A ? (B + Math.sqrt(B * B - 4 * A * C)) / (2 * A) : C / B);
        return {
            x: x1 + xa + xb * r,
            y: y1 + ya + yb * r,
            r: r
        };
    }

    function place(a, b, c) {
        var ax = a.x,
            ay = a.y,
            da = b.r + c.r,
            db = a.r + c.r,
            dx = b.x - ax,
            dy = b.y - ay,
            dc = dx * dx + dy * dy;
        if (dc) {
            var x = 0.5 + ((db *= db) - (da *= da)) / (2 * dc),
                y = Math.sqrt(Math.max(0, 2 * da * (db + dc) - (db -= dc) * db - da * da)) / (2 * dc);
            c.x = ax + x * dx + y * dy;
            c.y = ay + x * dy - y * dx;
        } else {
            c.x = ax + db;
            c.y = ay;
        }
    }

    function intersects(a, b) {
        var dx = b.x - a.x,
            dy = b.y - a.y,
            dr = a.r + b.r;
        return dr * dr - 1e-6 > dx * dx + dy * dy;
    }

    function score(node) {
        var a = node._,
            b = node.next._,
            ab = a.r + b.r,
            dx = (a.x * b.r + b.x * a.r) / ab,
            dy = (a.y * b.r + b.y * a.r) / ab;
        return dx * dx + dy * dy;
    }

    function Node$1(circle) {
        this._ = circle;
        this.next = null;
        this.previous = null;
    }

    function packEnclose(circles) {
        if (!(n = circles.length)) return 0;

        var a, b, c, n, aa, ca, i, j, k, sj, sk;

        // Place the first circle.
        a = circles[0], a.x = 0, a.y = 0;
        if (!(n > 1)) return a.r;

        // Place the second circle.
        b = circles[1], a.x = -b.r, b.x = a.r, b.y = 0;
        if (!(n > 2)) return a.r + b.r;

        // Place the third circle.
        place(b, a, c = circles[2]);

        // Initialize the front-chain using the first three circles a, b and c.
        a = new Node$1(a), b = new Node$1(b), c = new Node$1(c);
        a.next = c.previous = b;
        b.next = a.previous = c;
        c.next = b.previous = a;

        // Attempt to place each remaining circle…
        pack: for (i = 3; i < n; ++i) {
            place(a._, b._, c = circles[i]), c = new Node$1(c);

            // Find the closest intersecting circle on the front-chain, if any.
            // “Closeness” is determined by linear distance along the front-chain.
            // “Ahead” or “behind” is likewise determined by linear distance.
            j = b.next, k = a.previous, sj = b._.r, sk = a._.r;
            do {
                if (sj <= sk) {
                    if (intersects(j._, c._)) {
                        b = j, a.next = b, b.previous = a, --i;
                        continue pack;
                    }
                    sj += j._.r, j = j.next;
                } else {
                    if (intersects(k._, c._)) {
                        a = k, a.next = b, b.previous = a, --i;
                        continue pack;
                    }
                    sk += k._.r, k = k.previous;
                }
            } while (j !== k.next);

            // Success! Insert the new circle c between a and b.
            c.previous = a, c.next = b, a.next = b.previous = b = c;

            // Compute the new closest circle pair to the centroid.
            aa = score(a);
            while ((c = c.next) !== b) {
                if ((ca = score(c)) < aa) {
                    a = c, aa = ca;
                }
            }
            b = a.next;
        }

        // Compute the enclosing circle of the front chain.
        a = [b._], c = b; while ((c = c.next) !== b) a.push(c._); c = enclose(a);

        // Translate the circles to put the enclosing circle around the origin.
        for (i = 0; i < n; ++i) a = circles[i], a.x -= c.x, a.y -= c.y;

        return c.r;
    }

    function siblings(circles) {
        packEnclose(circles);
        return circles;
    }

    function optional(f) {
        return f == null ? null : required(f);
    }

    function required(f) {
        if (typeof f !== "function") throw new Error;
        return f;
    }

    function constantZero() {
        return 0;
    }

    function constant$8(x) {
        return function() {
            return x;
        };
    }

    function defaultRadius$1(d) {
        return Math.sqrt(d.value);
    }

    function index$2() {
        var radius = null,
            dx = 1,
            dy = 1,
            padding = constantZero;

        function pack(root) {
            root.x = dx / 2, root.y = dy / 2;
            if (radius) {
                root.eachBefore(radiusLeaf(radius))
                    .eachAfter(packChildren(padding, 0.5))
                    .eachBefore(translateChild(1));
            } else {
                root.eachBefore(radiusLeaf(defaultRadius$1))
                    .eachAfter(packChildren(constantZero, 1))
                    .eachAfter(packChildren(padding, root.r / Math.min(dx, dy)))
                    .eachBefore(translateChild(Math.min(dx, dy) / (2 * root.r)));
            }
            return root;
        }

        pack.radius = function(x) {
            return arguments.length ? (radius = optional(x), pack) : radius;
        };

        pack.size = function(x) {
            return arguments.length ? (dx = +x[0], dy = +x[1], pack) : [dx, dy];
        };

        pack.padding = function(x) {
            return arguments.length ? (padding = typeof x === "function" ? x : constant$8(+x), pack) : padding;
        };

        return pack;
    }

    function radiusLeaf(radius) {
        return function(node) {
            if (!node.children) {
                node.r = Math.max(0, +radius(node) || 0);
            }
        };
    }

    function packChildren(padding, k) {
        return function(node) {
            if (children = node.children) {
                var children,
                    i,
                    n = children.length,
                    r = padding(node) * k || 0,
                    e;

                if (r) for (i = 0; i < n; ++i) children[i].r += r;
                e = packEnclose(children);
                if (r) for (i = 0; i < n; ++i) children[i].r -= r;
                node.r = e + r;
            }
        };
    }

    function translateChild(k) {
        return function(node) {
            var parent = node.parent;
            node.r *= k;
            if (parent) {
                node.x = parent.x + k * node.x;
                node.y = parent.y + k * node.y;
            }
        };
    }

    function roundNode(node) {
        node.x0 = Math.round(node.x0);
        node.y0 = Math.round(node.y0);
        node.x1 = Math.round(node.x1);
        node.y1 = Math.round(node.y1);
    }

    function treemapDice(parent, x0, y0, x1, y1) {
        var nodes = parent.children,
            node,
            i = -1,
            n = nodes.length,
            k = parent.value && (x1 - x0) / parent.value;

        while (++i < n) {
            node = nodes[i], node.y0 = y0, node.y1 = y1;
            node.x0 = x0, node.x1 = x0 += node.value * k;
        }
    }

    function partition() {
        var dx = 1,
            dy = 1,
            padding = 0,
            round = false;

        function partition(root) {
            var n = root.height + 1;
            root.x0 =
                root.y0 = padding;
            root.x1 = dx;
            root.y1 = dy / n;
            root.eachBefore(positionNode(dy, n));
            if (round) root.eachBefore(roundNode);
            return root;
        }

        function positionNode(dy, n) {
            return function(node) {
                if (node.children) {
                    treemapDice(node, node.x0, dy * (node.depth + 1) / n, node.x1, dy * (node.depth + 2) / n);
                }
                var x0 = node.x0,
                    y0 = node.y0,
                    x1 = node.x1 - padding,
                    y1 = node.y1 - padding;
                if (x1 < x0) x0 = x1 = (x0 + x1) / 2;
                if (y1 < y0) y0 = y1 = (y0 + y1) / 2;
                node.x0 = x0;
                node.y0 = y0;
                node.x1 = x1;
                node.y1 = y1;
            };
        }

        partition.round = function(x) {
            return arguments.length ? (round = !!x, partition) : round;
        };

        partition.size = function(x) {
            return arguments.length ? (dx = +x[0], dy = +x[1], partition) : [dx, dy];
        };

        partition.padding = function(x) {
            return arguments.length ? (padding = +x, partition) : padding;
        };

        return partition;
    }

    var keyPrefix$1 = "$";
    var preroot = {depth: -1};
    var ambiguous = {};

    function defaultId(d) {
        return d.id;
    }

    function defaultParentId(d) {
        return d.parentId;
    }

    function stratify() {
        var id = defaultId,
            parentId = defaultParentId;

        function stratify(data) {
            var d,
                i,
                n = data.length,
                root,
                parent,
                node,
                nodes = new Array(n),
                nodeId,
                nodeKey,
                nodeByKey = {};

            for (i = 0; i < n; ++i) {
                d = data[i], node = nodes[i] = new Node(d);
                if ((nodeId = id(d, i, data)) != null && (nodeId += "")) {
                    nodeKey = keyPrefix$1 + (node.id = nodeId);
                    nodeByKey[nodeKey] = nodeKey in nodeByKey ? ambiguous : node;
                }
            }

            for (i = 0; i < n; ++i) {
                node = nodes[i], nodeId = parentId(data[i], i, data);
                if (nodeId == null || !(nodeId += "")) {
                    if (root) throw new Error("multiple roots");
                    root = node;
                } else {
                    parent = nodeByKey[keyPrefix$1 + nodeId];
                    if (!parent) throw new Error("missing: " + nodeId);
                    if (parent === ambiguous) throw new Error("ambiguous: " + nodeId);
                    if (parent.children) parent.children.push(node);
                    else parent.children = [node];
                    node.parent = parent;
                }
            }

            if (!root) throw new Error("no root");
            root.parent = preroot;
            root.eachBefore(function(node) { node.depth = node.parent.depth + 1; --n; }).eachBefore(computeHeight);
            root.parent = null;
            if (n > 0) throw new Error("cycle");

            return root;
        }

        stratify.id = function(x) {
            return arguments.length ? (id = required(x), stratify) : id;
        };

        stratify.parentId = function(x) {
            return arguments.length ? (parentId = required(x), stratify) : parentId;
        };

        return stratify;
    }

    function defaultSeparation$1(a, b) {
        return a.parent === b.parent ? 1 : 2;
    }

// function radialSeparation(a, b) {
//   return (a.parent === b.parent ? 1 : 2) / a.depth;
// }

// This function is used to traverse the left contour of a subtree (or
// subforest). It returns the successor of v on this contour. This successor is
// either given by the leftmost child of v or by the thread of v. The function
// returns null if and only if v is on the highest level of its subtree.
    function nextLeft(v) {
        var children = v.children;
        return children ? children[0] : v.t;
    }

// This function works analogously to nextLeft.
    function nextRight(v) {
        var children = v.children;
        return children ? children[children.length - 1] : v.t;
    }

// Shifts the current subtree rooted at w+. This is done by increasing
// prelim(w+) and mod(w+) by shift.
    function moveSubtree(wm, wp, shift) {
        var change = shift / (wp.i - wm.i);
        wp.c -= change;
        wp.s += shift;
        wm.c += change;
        wp.z += shift;
        wp.m += shift;
    }

// All other shifts, applied to the smaller subtrees between w- and w+, are
// performed by this function. To prepare the shifts, we have to adjust
// change(w+), shift(w+), and change(w-).
    function executeShifts(v) {
        var shift = 0,
            change = 0,
            children = v.children,
            i = children.length,
            w;
        while (--i >= 0) {
            w = children[i];
            w.z += shift;
            w.m += shift;
            shift += w.s + (change += w.c);
        }
    }

// If vi-’s ancestor is a sibling of v, returns vi-’s ancestor. Otherwise,
// returns the specified (default) ancestor.
    function nextAncestor(vim, v, ancestor) {
        return vim.a.parent === v.parent ? vim.a : ancestor;
    }

    function TreeNode(node, i) {
        this._ = node;
        this.parent = null;
        this.children = null;
        this.A = null; // default ancestor
        this.a = this; // ancestor
        this.z = 0; // prelim
        this.m = 0; // mod
        this.c = 0; // change
        this.s = 0; // shift
        this.t = null; // thread
        this.i = i; // number
    }

    TreeNode.prototype = Object.create(Node.prototype);

    function treeRoot(root) {
        var tree = new TreeNode(root, 0),
            node,
            nodes = [tree],
            child,
            children,
            i,
            n;

        while (node = nodes.pop()) {
            if (children = node._.children) {
                node.children = new Array(n = children.length);
                for (i = n - 1; i >= 0; --i) {
                    nodes.push(child = node.children[i] = new TreeNode(children[i], i));
                    child.parent = node;
                }
            }
        }

        (tree.parent = new TreeNode(null, 0)).children = [tree];
        return tree;
    }

// Node-link tree diagram using the Reingold-Tilford "tidy" algorithm
    function tree() {
        var separation = defaultSeparation$1,
            dx = 1,
            dy = 1,
            nodeSize = null;

        function tree(root) {
            var t = treeRoot(root);

            // Compute the layout using Buchheim et al.’s algorithm.
            t.eachAfter(firstWalk), t.parent.m = -t.z;
            t.eachBefore(secondWalk);

            // If a fixed node size is specified, scale x and y.
            if (nodeSize) root.eachBefore(sizeNode);

                // If a fixed tree size is specified, scale x and y based on the extent.
            // Compute the left-most, right-most, and depth-most nodes for extents.
            else {
                var left = root,
                    right = root,
                    bottom = root;
                root.eachBefore(function(node) {
                    if (node.x < left.x) left = node;
                    if (node.x > right.x) right = node;
                    if (node.depth > bottom.depth) bottom = node;
                });
                var s = left === right ? 1 : separation(left, right) / 2,
                    tx = s - left.x,
                    kx = dx / (right.x + s + tx),
                    ky = dy / (bottom.depth || 1);
                root.eachBefore(function(node) {
                    node.x = (node.x + tx) * kx;
                    node.y = node.depth * ky;
                });
            }

            return root;
        }

        // Computes a preliminary x-coordinate for v. Before that, FIRST WALK is
        // applied recursively to the children of v, as well as the function
        // APPORTION. After spacing out the children by calling EXECUTE SHIFTS, the
        // node v is placed to the midpoint of its outermost children.
        function firstWalk(v) {
            var children = v.children,
                siblings = v.parent.children,
                w = v.i ? siblings[v.i - 1] : null;
            if (children) {
                executeShifts(v);
                var midpoint = (children[0].z + children[children.length - 1].z) / 2;
                if (w) {
                    v.z = w.z + separation(v._, w._);
                    v.m = v.z - midpoint;
                } else {
                    v.z = midpoint;
                }
            } else if (w) {
                v.z = w.z + separation(v._, w._);
            }
            v.parent.A = apportion(v, w, v.parent.A || siblings[0]);
        }

        // Computes all real x-coordinates by summing up the modifiers recursively.
        function secondWalk(v) {
            v._.x = v.z + v.parent.m;
            v.m += v.parent.m;
        }

        // The core of the algorithm. Here, a new subtree is combined with the
        // previous subtrees. Threads are used to traverse the inside and outside
        // contours of the left and right subtree up to the highest common level. The
        // vertices used for the traversals are vi+, vi-, vo-, and vo+, where the
        // superscript o means outside and i means inside, the subscript - means left
        // subtree and + means right subtree. For summing up the modifiers along the
        // contour, we use respective variables si+, si-, so-, and so+. Whenever two
        // nodes of the inside contours conflict, we compute the left one of the
        // greatest uncommon ancestors using the function ANCESTOR and call MOVE
        // SUBTREE to shift the subtree and prepare the shifts of smaller subtrees.
        // Finally, we add a new thread (if necessary).
        function apportion(v, w, ancestor) {
            if (w) {
                var vip = v,
                    vop = v,
                    vim = w,
                    vom = vip.parent.children[0],
                    sip = vip.m,
                    sop = vop.m,
                    sim = vim.m,
                    som = vom.m,
                    shift;
                while (vim = nextRight(vim), vip = nextLeft(vip), vim && vip) {
                    vom = nextLeft(vom);
                    vop = nextRight(vop);
                    vop.a = v;
                    shift = vim.z + sim - vip.z - sip + separation(vim._, vip._);
                    if (shift > 0) {
                        moveSubtree(nextAncestor(vim, v, ancestor), v, shift);
                        sip += shift;
                        sop += shift;
                    }
                    sim += vim.m;
                    sip += vip.m;
                    som += vom.m;
                    sop += vop.m;
                }
                if (vim && !nextRight(vop)) {
                    vop.t = vim;
                    vop.m += sim - sop;
                }
                if (vip && !nextLeft(vom)) {
                    vom.t = vip;
                    vom.m += sip - som;
                    ancestor = v;
                }
            }
            return ancestor;
        }

        function sizeNode(node) {
            node.x *= dx;
            node.y = node.depth * dy;
        }

        tree.separation = function(x) {
            return arguments.length ? (separation = x, tree) : separation;
        };

        tree.size = function(x) {
            return arguments.length ? (nodeSize = false, dx = +x[0], dy = +x[1], tree) : (nodeSize ? null : [dx, dy]);
        };

        tree.nodeSize = function(x) {
            return arguments.length ? (nodeSize = true, dx = +x[0], dy = +x[1], tree) : (nodeSize ? [dx, dy] : null);
        };

        return tree;
    }

    function treemapSlice(parent, x0, y0, x1, y1) {
        var nodes = parent.children,
            node,
            i = -1,
            n = nodes.length,
            k = parent.value && (y1 - y0) / parent.value;

        while (++i < n) {
            node = nodes[i], node.x0 = x0, node.x1 = x1;
            node.y0 = y0, node.y1 = y0 += node.value * k;
        }
    }

    var phi = (1 + Math.sqrt(5)) / 2;

    function squarifyRatio(ratio, parent, x0, y0, x1, y1) {
        var rows = [],
            nodes = parent.children,
            row,
            nodeValue,
            i0 = 0,
            i1 = 0,
            n = nodes.length,
            dx, dy,
            value = parent.value,
            sumValue,
            minValue,
            maxValue,
            newRatio,
            minRatio,
            alpha,
            beta;

        while (i0 < n) {
            dx = x1 - x0, dy = y1 - y0;

            // Find the next non-empty node.
            do sumValue = nodes[i1++].value; while (!sumValue && i1 < n);
            minValue = maxValue = sumValue;
            alpha = Math.max(dy / dx, dx / dy) / (value * ratio);
            beta = sumValue * sumValue * alpha;
            minRatio = Math.max(maxValue / beta, beta / minValue);

            // Keep adding nodes while the aspect ratio maintains or improves.
            for (; i1 < n; ++i1) {
                sumValue += nodeValue = nodes[i1].value;
                if (nodeValue < minValue) minValue = nodeValue;
                if (nodeValue > maxValue) maxValue = nodeValue;
                beta = sumValue * sumValue * alpha;
                newRatio = Math.max(maxValue / beta, beta / minValue);
                if (newRatio > minRatio) { sumValue -= nodeValue; break; }
                minRatio = newRatio;
            }

            // Position and record the row orientation.
            rows.push(row = {value: sumValue, dice: dx < dy, children: nodes.slice(i0, i1)});
            if (row.dice) treemapDice(row, x0, y0, x1, value ? y0 += dy * sumValue / value : y1);
            else treemapSlice(row, x0, y0, value ? x0 += dx * sumValue / value : x1, y1);
            value -= sumValue, i0 = i1;
        }

        return rows;
    }

    var squarify = (function custom(ratio) {

        function squarify(parent, x0, y0, x1, y1) {
            squarifyRatio(ratio, parent, x0, y0, x1, y1);
        }

        squarify.ratio = function(x) {
            return custom((x = +x) > 1 ? x : 1);
        };

        return squarify;
    })(phi);

    function index$3() {
        var tile = squarify,
            round = false,
            dx = 1,
            dy = 1,
            paddingStack = [0],
            paddingInner = constantZero,
            paddingTop = constantZero,
            paddingRight = constantZero,
            paddingBottom = constantZero,
            paddingLeft = constantZero;

        function treemap(root) {
            root.x0 =
                root.y0 = 0;
            root.x1 = dx;
            root.y1 = dy;
            root.eachBefore(positionNode);
            paddingStack = [0];
            if (round) root.eachBefore(roundNode);
            return root;
        }

        function positionNode(node) {
            var p = paddingStack[node.depth],
                x0 = node.x0 + p,
                y0 = node.y0 + p,
                x1 = node.x1 - p,
                y1 = node.y1 - p;
            if (x1 < x0) x0 = x1 = (x0 + x1) / 2;
            if (y1 < y0) y0 = y1 = (y0 + y1) / 2;
            node.x0 = x0;
            node.y0 = y0;
            node.x1 = x1;
            node.y1 = y1;
            if (node.children) {
                p = paddingStack[node.depth + 1] = paddingInner(node) / 2;
                x0 += paddingLeft(node) - p;
                y0 += paddingTop(node) - p;
                x1 -= paddingRight(node) - p;
                y1 -= paddingBottom(node) - p;
                if (x1 < x0) x0 = x1 = (x0 + x1) / 2;
                if (y1 < y0) y0 = y1 = (y0 + y1) / 2;
                tile(node, x0, y0, x1, y1);
            }
        }

        treemap.round = function(x) {
            return arguments.length ? (round = !!x, treemap) : round;
        };

        treemap.size = function(x) {
            return arguments.length ? (dx = +x[0], dy = +x[1], treemap) : [dx, dy];
        };

        treemap.tile = function(x) {
            return arguments.length ? (tile = required(x), treemap) : tile;
        };

        treemap.padding = function(x) {
            return arguments.length ? treemap.paddingInner(x).paddingOuter(x) : treemap.paddingInner();
        };

        treemap.paddingInner = function(x) {
            return arguments.length ? (paddingInner = typeof x === "function" ? x : constant$8(+x), treemap) : paddingInner;
        };

        treemap.paddingOuter = function(x) {
            return arguments.length ? treemap.paddingTop(x).paddingRight(x).paddingBottom(x).paddingLeft(x) : treemap.paddingTop();
        };

        treemap.paddingTop = function(x) {
            return arguments.length ? (paddingTop = typeof x === "function" ? x : constant$8(+x), treemap) : paddingTop;
        };

        treemap.paddingRight = function(x) {
            return arguments.length ? (paddingRight = typeof x === "function" ? x : constant$8(+x), treemap) : paddingRight;
        };

        treemap.paddingBottom = function(x) {
            return arguments.length ? (paddingBottom = typeof x === "function" ? x : constant$8(+x), treemap) : paddingBottom;
        };

        treemap.paddingLeft = function(x) {
            return arguments.length ? (paddingLeft = typeof x === "function" ? x : constant$8(+x), treemap) : paddingLeft;
        };

        return treemap;
    }

    function binary(parent, x0, y0, x1, y1) {
        var nodes = parent.children,
            i, n = nodes.length,
            sum, sums = new Array(n + 1);

        for (sums[0] = sum = i = 0; i < n; ++i) {
            sums[i + 1] = sum += nodes[i].value;
        }

        partition(0, n, parent.value, x0, y0, x1, y1);

        function partition(i, j, value, x0, y0, x1, y1) {
            if (i >= j - 1) {
                var node = nodes[i];
                node.x0 = x0, node.y0 = y0;
                node.x1 = x1, node.y1 = y1;
                return;
            }

            var valueOffset = sums[i],
                valueTarget = (value / 2) + valueOffset,
                k = i + 1,
                hi = j - 1;

            while (k < hi) {
                var mid = k + hi >>> 1;
                if (sums[mid] < valueTarget) k = mid + 1;
                else hi = mid;
            }

            if ((valueTarget - sums[k - 1]) < (sums[k] - valueTarget) && i + 1 < k) --k;

            var valueLeft = sums[k] - valueOffset,
                valueRight = value - valueLeft;

            if ((x1 - x0) > (y1 - y0)) {
                var xk = (x0 * valueRight + x1 * valueLeft) / value;
                partition(i, k, valueLeft, x0, y0, xk, y1);
                partition(k, j, valueRight, xk, y0, x1, y1);
            } else {
                var yk = (y0 * valueRight + y1 * valueLeft) / value;
                partition(i, k, valueLeft, x0, y0, x1, yk);
                partition(k, j, valueRight, x0, yk, x1, y1);
            }
        }
    }

    function sliceDice(parent, x0, y0, x1, y1) {
        (parent.depth & 1 ? treemapSlice : treemapDice)(parent, x0, y0, x1, y1);
    }

    var resquarify = (function custom(ratio) {

        function resquarify(parent, x0, y0, x1, y1) {
            if ((rows = parent._squarify) && (rows.ratio === ratio)) {
                var rows,
                    row,
                    nodes,
                    i,
                    j = -1,
                    n,
                    m = rows.length,
                    value = parent.value;

                while (++j < m) {
                    row = rows[j], nodes = row.children;
                    for (i = row.value = 0, n = nodes.length; i < n; ++i) row.value += nodes[i].value;
                    if (row.dice) treemapDice(row, x0, y0, x1, y0 += (y1 - y0) * row.value / value);
                    else treemapSlice(row, x0, y0, x0 += (x1 - x0) * row.value / value, y1);
                    value -= row.value;
                }
            } else {
                parent._squarify = rows = squarifyRatio(ratio, parent, x0, y0, x1, y1);
                rows.ratio = ratio;
            }
        }

        resquarify.ratio = function(x) {
            return custom((x = +x) > 1 ? x : 1);
        };

        return resquarify;
    })(phi);

    function area$1(polygon) {
        var i = -1,
            n = polygon.length,
            a,
            b = polygon[n - 1],
            area = 0;

        while (++i < n) {
            a = b;
            b = polygon[i];
            area += a[1] * b[0] - a[0] * b[1];
        }

        return area / 2;
    }

    function centroid$1(polygon) {
        var i = -1,
            n = polygon.length,
            x = 0,
            y = 0,
            a,
            b = polygon[n - 1],
            c,
            k = 0;

        while (++i < n) {
            a = b;
            b = polygon[i];
            k += c = a[0] * b[1] - b[0] * a[1];
            x += (a[0] + b[0]) * c;
            y += (a[1] + b[1]) * c;
        }

        return k *= 3, [x / k, y / k];
    }

// Returns the 2D cross product of AB and AC vectors, i.e., the z-component of
// the 3D cross product in a quadrant I Cartesian coordinate system (+x is
// right, +y is up). Returns a positive value if ABC is counter-clockwise,
// negative if clockwise, and zero if the points are collinear.
    function cross$1(a, b, c) {
        return (b[0] - a[0]) * (c[1] - a[1]) - (b[1] - a[1]) * (c[0] - a[0]);
    }

    function lexicographicOrder(a, b) {
        return a[0] - b[0] || a[1] - b[1];
    }

// Computes the upper convex hull per the monotone chain algorithm.
// Assumes points.length >= 3, is sorted by x, unique in y.
// Returns an array of indices into points in left-to-right order.
    function computeUpperHullIndexes(points) {
        var n = points.length,
            indexes = [0, 1],
            size = 2;

        for (var i = 2; i < n; ++i) {
            while (size > 1 && cross$1(points[indexes[size - 2]], points[indexes[size - 1]], points[i]) <= 0) --size;
            indexes[size++] = i;
        }

        return indexes.slice(0, size); // remove popped points
    }

    function hull(points) {
        if ((n = points.length) < 3) return null;

        var i,
            n,
            sortedPoints = new Array(n),
            flippedPoints = new Array(n);

        for (i = 0; i < n; ++i) sortedPoints[i] = [+points[i][0], +points[i][1], i];
        sortedPoints.sort(lexicographicOrder);
        for (i = 0; i < n; ++i) flippedPoints[i] = [sortedPoints[i][0], -sortedPoints[i][1]];

        var upperIndexes = computeUpperHullIndexes(sortedPoints),
            lowerIndexes = computeUpperHullIndexes(flippedPoints);

        // Construct the hull polygon, removing possible duplicate endpoints.
        var skipLeft = lowerIndexes[0] === upperIndexes[0],
            skipRight = lowerIndexes[lowerIndexes.length - 1] === upperIndexes[upperIndexes.length - 1],
            hull = [];

        // Add upper hull in right-to-l order.
        // Then add lower hull in left-to-right order.
        for (i = upperIndexes.length - 1; i >= 0; --i) hull.push(points[sortedPoints[upperIndexes[i]][2]]);
        for (i = +skipLeft; i < lowerIndexes.length - skipRight; ++i) hull.push(points[sortedPoints[lowerIndexes[i]][2]]);

        return hull;
    }

    function contains$1(polygon, point) {
        var n = polygon.length,
            p = polygon[n - 1],
            x = point[0], y = point[1],
            x0 = p[0], y0 = p[1],
            x1, y1,
            inside = false;

        for (var i = 0; i < n; ++i) {
            p = polygon[i], x1 = p[0], y1 = p[1];
            if (((y1 > y) !== (y0 > y)) && (x < (x0 - x1) * (y - y1) / (y0 - y1) + x1)) inside = !inside;
            x0 = x1, y0 = y1;
        }

        return inside;
    }

    function length$2(polygon) {
        var i = -1,
            n = polygon.length,
            b = polygon[n - 1],
            xa,
            ya,
            xb = b[0],
            yb = b[1],
            perimeter = 0;

        while (++i < n) {
            xa = xb;
            ya = yb;
            b = polygon[i];
            xb = b[0];
            yb = b[1];
            xa -= xb;
            ya -= yb;
            perimeter += Math.sqrt(xa * xa + ya * ya);
        }

        return perimeter;
    }

    var slice$4 = [].slice;

    var noabort = {};

    function Queue(size) {
        this._size = size;
        this._call =
            this._error = null;
        this._tasks = [];
        this._data = [];
        this._waiting =
            this._active =
                this._ended =
                    this._start = 0; // inside a synchronous task callback?
    }

    Queue.prototype = queue.prototype = {
        constructor: Queue,
        defer: function(callback) {
            if (typeof callback !== "function") throw new Error("invalid callback");
            if (this._call) throw new Error("defer after await");
            if (this._error != null) return this;
            var t = slice$4.call(arguments, 1);
            t.push(callback);
            ++this._waiting, this._tasks.push(t);
            poke$1(this);
            return this;
        },
        abort: function() {
            if (this._error == null) abort(this, new Error("abort"));
            return this;
        },
        await: function(callback) {
            if (typeof callback !== "function") throw new Error("invalid callback");
            if (this._call) throw new Error("multiple await");
            this._call = function(error, results) { callback.apply(null, [error].concat(results)); };
            maybeNotify(this);
            return this;
        },
        awaitAll: function(callback) {
            if (typeof callback !== "function") throw new Error("invalid callback");
            if (this._call) throw new Error("multiple await");
            this._call = callback;
            maybeNotify(this);
            return this;
        }
    };

    function poke$1(q) {
        if (!q._start) {
            try { start$1(q); } // let the current task complete
            catch (e) {
                if (q._tasks[q._ended + q._active - 1]) abort(q, e); // task errored synchronously
                else if (!q._data) throw e; // await callback errored synchronously
            }
        }
    }

    function start$1(q) {
        while (q._start = q._waiting && q._active < q._size) {
            var i = q._ended + q._active,
                t = q._tasks[i],
                j = t.length - 1,
                c = t[j];
            t[j] = end(q, i);
            --q._waiting, ++q._active;
            t = c.apply(null, t);
            if (!q._tasks[i]) continue; // task finished synchronously
            q._tasks[i] = t || noabort;
        }
    }

    function end(q, i) {
        return function(e, r) {
            if (!q._tasks[i]) return; // ignore multiple callbacks
            --q._active, ++q._ended;
            q._tasks[i] = null;
            if (q._error != null) return; // ignore secondary errors
            if (e != null) {
                abort(q, e);
            } else {
                q._data[i] = r;
                if (q._waiting) poke$1(q);
                else maybeNotify(q);
            }
        };
    }

    function abort(q, e) {
        var i = q._tasks.length, t;
        q._error = e; // ignore active callbacks
        q._data = undefined; // allow gc
        q._waiting = NaN; // prevent starting

        while (--i >= 0) {
            if (t = q._tasks[i]) {
                q._tasks[i] = null;
                if (t.abort) {
                    try { t.abort(); }
                    catch (e) { /* ignore */ }
                }
            }
        }

        q._active = NaN; // allow notification
        maybeNotify(q);
    }

    function maybeNotify(q) {
        if (!q._active && q._call) {
            var d = q._data;
            q._data = undefined; // allow gc
            q._call(q._error, d);
        }
    }

    function queue(concurrency) {
        if (concurrency == null) concurrency = Infinity;
        else if (!((concurrency = +concurrency) >= 1)) throw new Error("invalid concurrency");
        return new Queue(concurrency);
    }

    function defaultSource$1() {
        return Math.random();
    }

    var uniform = (function sourceRandomUniform(source) {
        function randomUniform(min, max) {
            min = min == null ? 0 : +min;
            max = max == null ? 1 : +max;
            if (arguments.length === 1) max = min, min = 0;
            else max -= min;
            return function() {
                return source() * max + min;
            };
        }

        randomUniform.source = sourceRandomUniform;

        return randomUniform;
    })(defaultSource$1);

    var normal = (function sourceRandomNormal(source) {
        function randomNormal(mu, sigma) {
            var x, r;
            mu = mu == null ? 0 : +mu;
            sigma = sigma == null ? 1 : +sigma;
            return function() {
                var y;

                // If available, use the second previously-generated uniform random.
                if (x != null) y = x, x = null;

                // Otherwise, generate a new x and y.
                else do {
                    x = source() * 2 - 1;
                    y = source() * 2 - 1;
                    r = x * x + y * y;
                } while (!r || r > 1);

                return mu + sigma * y * Math.sqrt(-2 * Math.log(r) / r);
            };
        }

        randomNormal.source = sourceRandomNormal;

        return randomNormal;
    })(defaultSource$1);

    var logNormal = (function sourceRandomLogNormal(source) {
        function randomLogNormal() {
            var randomNormal = normal.source(source).apply(this, arguments);
            return function() {
                return Math.exp(randomNormal());
            };
        }

        randomLogNormal.source = sourceRandomLogNormal;

        return randomLogNormal;
    })(defaultSource$1);

    var irwinHall = (function sourceRandomIrwinHall(source) {
        function randomIrwinHall(n) {
            return function() {
                for (var sum = 0, i = 0; i < n; ++i) sum += source();
                return sum;
            };
        }

        randomIrwinHall.source = sourceRandomIrwinHall;

        return randomIrwinHall;
    })(defaultSource$1);

    var bates = (function sourceRandomBates(source) {
        function randomBates(n) {
            var randomIrwinHall = irwinHall.source(source)(n);
            return function() {
                return randomIrwinHall() / n;
            };
        }

        randomBates.source = sourceRandomBates;

        return randomBates;
    })(defaultSource$1);

    var exponential$1 = (function sourceRandomExponential(source) {
        function randomExponential(lambda) {
            return function() {
                return -Math.log(1 - source()) / lambda;
            };
        }

        randomExponential.source = sourceRandomExponential;

        return randomExponential;
    })(defaultSource$1);

    function request(url, callback) {
        var request,
            event = dispatch("beforesend", "progress", "load", "error"),
            mimeType,
            headers = map$1(),
            xhr = new XMLHttpRequest,
            user = null,
            password = null,
            response,
            responseType,
            timeout = 0;

        // If IE does not support CORS, use XDomainRequest.
        if (typeof XDomainRequest !== "undefined"
            && !("withCredentials" in xhr)
            && /^(http(s)?:)?\/\//.test(url)) xhr = new XDomainRequest;

        "onload" in xhr
            ? xhr.onload = xhr.onerror = xhr.ontimeout = respond
            : xhr.onreadystatechange = function(o) { xhr.readyState > 3 && respond(o); };

        function respond(o) {
            var status = xhr.status, result;
            if (!status && hasResponse(xhr)
                || status >= 200 && status < 300
                || status === 304) {
                if (response) {
                    try {
                        result = response.call(request, xhr);
                    } catch (e) {
                        event.call("error", request, e);
                        return;
                    }
                } else {
                    result = xhr;
                }
                event.call("load", request, result);
            } else {
                event.call("error", request, o);
            }
        }

        xhr.onprogress = function(e) {
            event.call("progress", request, e);
        };

        request = {
            header: function(name, value) {
                name = (name + "").toLowerCase();
                if (arguments.length < 2) return headers.get(name);
                if (value == null) headers.remove(name);
                else headers.set(name, value + "");
                return request;
            },

            // If mimeType is non-null and no Accept header is set, a default is used.
            mimeType: function(value) {
                if (!arguments.length) return mimeType;
                mimeType = value == null ? null : value + "";
                return request;
            },

            // Specifies what type the response value should take;
            // for instance, arraybuffer, blob, document, or text.
            responseType: function(value) {
                if (!arguments.length) return responseType;
                responseType = value;
                return request;
            },

            timeout: function(value) {
                if (!arguments.length) return timeout;
                timeout = +value;
                return request;
            },

            user: function(value) {
                return arguments.length < 1 ? user : (user = value == null ? null : value + "", request);
            },

            password: function(value) {
                return arguments.length < 1 ? password : (password = value == null ? null : value + "", request);
            },

            // Specify how to convert the response content to a specific type;
            // changes the callback value on "load" events.
            response: function(value) {
                response = value;
                return request;
            },

            // Alias for send("GET", …).
            get: function(data, callback) {
                return request.send("GET", data, callback);
            },

            // Alias for send("POST", …).
            post: function(data, callback) {
                return request.send("POST", data, callback);
            },

            // If callback is non-null, it will be used for error and load events.
            send: function(method, data, callback) {
                xhr.open(method, url, true, user, password);
                if (mimeType != null && !headers.has("accept")) headers.set("accept", mimeType + ",*/*");
                if (xhr.setRequestHeader) headers.each(function(value, name) { xhr.setRequestHeader(name, value); });
                if (mimeType != null && xhr.overrideMimeType) xhr.overrideMimeType(mimeType);
                if (responseType != null) xhr.responseType = responseType;
                if (timeout > 0) xhr.timeout = timeout;
                if (callback == null && typeof data === "function") callback = data, data = null;
                if (callback != null && callback.length === 1) callback = fixCallback(callback);
                if (callback != null) request.on("error", callback).on("load", function(xhr) { callback(null, xhr); });
                event.call("beforesend", request, xhr);
                xhr.send(data == null ? null : data);
                return request;
            },

            abort: function() {
                xhr.abort();
                return request;
            },

            on: function() {
                var value = event.on.apply(event, arguments);
                return value === event ? request : value;
            }
        };

        if (callback != null) {
            if (typeof callback !== "function") throw new Error("invalid callback: " + callback);
            return request.get(callback);
        }

        return request;
    }

    function fixCallback(callback) {
        return function(error, xhr) {
            callback(error == null ? xhr : null);
        };
    }

    function hasResponse(xhr) {
        var type = xhr.responseType;
        return type && type !== "text"
            ? xhr.response // null on error
            : xhr.responseText; // "" on error
    }

    function type$1(defaultMimeType, response) {
        return function(url, callback) {
            var r = request(url).mimeType(defaultMimeType).response(response);
            if (callback != null) {
                if (typeof callback !== "function") throw new Error("invalid callback: " + callback);
                return r.get(callback);
            }
            return r;
        };
    }

    var html = type$1("text/html", function(xhr) {
        return document.createRange().createContextualFragment(xhr.responseText);
    });

    var json = type$1("application/json", function(xhr) {
        return JSON.parse(xhr.responseText);
    });

    var text = type$1("text/plain", function(xhr) {
        return xhr.responseText;
    });

    var xml = type$1("application/xml", function(xhr) {
        var xml = xhr.responseXML;
        if (!xml) throw new Error("parse error");
        return xml;
    });

    function dsv$1(defaultMimeType, parse) {
        return function(url, row, callback) {
            if (arguments.length < 3) callback = row, row = null;
            var r = request(url).mimeType(defaultMimeType);
            r.row = function(_) { return arguments.length ? r.response(responseOf(parse, row = _)) : row; };
            r.row(row);
            return callback ? r.get(callback) : r;
        };
    }

    function responseOf(parse, row) {
        return function(request$$1) {
            return parse(request$$1.responseText, row);
        };
    }

    var csv$1 = dsv$1("text/csv", csvParse);

    var tsv$1 = dsv$1("text/tab-separated-values", tsvParse);

    var array$2 = Array.prototype;

    var map$3 = array$2.map;
    var slice$5 = array$2.slice;

    var implicit = {name: "implicit"};

    function ordinal(range) {
        var index = map$1(),
            domain = [],
            unknown = implicit;

        range = range == null ? [] : slice$5.call(range);

        function scale(d) {
            var key = d + "", i = index.get(key);
            if (!i) {
                if (unknown !== implicit) return unknown;
                index.set(key, i = domain.push(d));
            }
            return range[(i - 1) % range.length];
        }

        scale.domain = function(_) {
            if (!arguments.length) return domain.slice();
            domain = [], index = map$1();
            var i = -1, n = _.length, d, key;
            while (++i < n) if (!index.has(key = (d = _[i]) + "")) index.set(key, domain.push(d));
            return scale;
        };

        scale.range = function(_) {
            return arguments.length ? (range = slice$5.call(_), scale) : range.slice();
        };

        scale.unknown = function(_) {
            return arguments.length ? (unknown = _, scale) : unknown;
        };

        scale.copy = function() {
            return ordinal()
                .domain(domain)
                .range(range)
                .unknown(unknown);
        };

        return scale;
    }

    function band() {
        var scale = ordinal().unknown(undefined),
            domain = scale.domain,
            ordinalRange = scale.range,
            range$$1 = [0, 1],
            step,
            bandwidth,
            round = false,
            paddingInner = 0,
            paddingOuter = 0,
            align = 0.5;

        delete scale.unknown;

        function rescale() {
            var n = domain().length,
                reverse = range$$1[1] < range$$1[0],
                start = range$$1[reverse - 0],
                stop = range$$1[1 - reverse];
            step = (stop - start) / Math.max(1, n - paddingInner + paddingOuter * 2);
            if (round) step = Math.floor(step);
            start += (stop - start - step * (n - paddingInner)) * align;
            bandwidth = step * (1 - paddingInner);
            if (round) start = Math.round(start), bandwidth = Math.round(bandwidth);
            var values = sequence(n).map(function(i) { return start + step * i; });
            return ordinalRange(reverse ? values.reverse() : values);
        }

        scale.domain = function(_) {
            return arguments.length ? (domain(_), rescale()) : domain();
        };

        scale.range = function(_) {
            return arguments.length ? (range$$1 = [+_[0], +_[1]], rescale()) : range$$1.slice();
        };

        scale.rangeRound = function(_) {
            return range$$1 = [+_[0], +_[1]], round = true, rescale();
        };

        scale.bandwidth = function() {
            return bandwidth;
        };

        scale.step = function() {
            return step;
        };

        scale.round = function(_) {
            return arguments.length ? (round = !!_, rescale()) : round;
        };

        scale.padding = function(_) {
            return arguments.length ? (paddingInner = paddingOuter = Math.max(0, Math.min(1, _)), rescale()) : paddingInner;
        };

        scale.paddingInner = function(_) {
            return arguments.length ? (paddingInner = Math.max(0, Math.min(1, _)), rescale()) : paddingInner;
        };

        scale.paddingOuter = function(_) {
            return arguments.length ? (paddingOuter = Math.max(0, Math.min(1, _)), rescale()) : paddingOuter;
        };

        scale.align = function(_) {
            return arguments.length ? (align = Math.max(0, Math.min(1, _)), rescale()) : align;
        };

        scale.copy = function() {
            return band()
                .domain(domain())
                .range(range$$1)
                .round(round)
                .paddingInner(paddingInner)
                .paddingOuter(paddingOuter)
                .align(align);
        };

        return rescale();
    }

    function pointish(scale) {
        var copy = scale.copy;

        scale.padding = scale.paddingOuter;
        delete scale.paddingInner;
        delete scale.paddingOuter;

        scale.copy = function() {
            return pointish(copy());
        };

        return scale;
    }

    function point$1() {
        return pointish(band().paddingInner(1));
    }

    function constant$9(x) {
        return function() {
            return x;
        };
    }

    function number$2(x) {
        return +x;
    }

    var unit = [0, 1];

    function deinterpolateLinear(a, b) {
        return (b -= (a = +a))
            ? function(x) { return (x - a) / b; }
            : constant$9(b);
    }

    function deinterpolateClamp(deinterpolate) {
        return function(a, b) {
            var d = deinterpolate(a = +a, b = +b);
            return function(x) { return x <= a ? 0 : x >= b ? 1 : d(x); };
        };
    }

    function reinterpolateClamp(reinterpolate) {
        return function(a, b) {
            var r = reinterpolate(a = +a, b = +b);
            return function(t) { return t <= 0 ? a : t >= 1 ? b : r(t); };
        };
    }

    function bimap(domain, range, deinterpolate, reinterpolate) {
        var d0 = domain[0], d1 = domain[1], r0 = range[0], r1 = range[1];
        if (d1 < d0) d0 = deinterpolate(d1, d0), r0 = reinterpolate(r1, r0);
        else d0 = deinterpolate(d0, d1), r0 = reinterpolate(r0, r1);
        return function(x) { return r0(d0(x)); };
    }

    function polymap(domain, range, deinterpolate, reinterpolate) {
        var j = Math.min(domain.length, range.length) - 1,
            d = new Array(j),
            r = new Array(j),
            i = -1;

        // Reverse descending domains.
        if (domain[j] < domain[0]) {
            domain = domain.slice().reverse();
            range = range.slice().reverse();
        }

        while (++i < j) {
            d[i] = deinterpolate(domain[i], domain[i + 1]);
            r[i] = reinterpolate(range[i], range[i + 1]);
        }

        return function(x) {
            var i = bisectRight(domain, x, 1, j) - 1;
            return r[i](d[i](x));
        };
    }

    function copy(source, target) {
        return target
            .domain(source.domain())
            .range(source.range())
            .interpolate(source.interpolate())
            .clamp(source.clamp());
    }

// deinterpolate(a, b)(x) takes a domain value x in [a,b] and returns the corresponding parameter t in [0,1].
// reinterpolate(a, b)(t) takes a parameter t in [0,1] and returns the corresponding domain value x in [a,b].
    function continuous(deinterpolate, reinterpolate) {
        var domain = unit,
            range = unit,
            interpolate$$1 = interpolateValue,
            clamp = false,
            piecewise,
            output,
            input;

        function rescale() {
            piecewise = Math.min(domain.length, range.length) > 2 ? polymap : bimap;
            output = input = null;
            return scale;
        }

        function scale(x) {
            return (output || (output = piecewise(domain, range, clamp ? deinterpolateClamp(deinterpolate) : deinterpolate, interpolate$$1)))(+x);
        }

        scale.invert = function(y) {
            return (input || (input = piecewise(range, domain, deinterpolateLinear, clamp ? reinterpolateClamp(reinterpolate) : reinterpolate)))(+y);
        };

        scale.domain = function(_) {
            return arguments.length ? (domain = map$3.call(_, number$2), rescale()) : domain.slice();
        };

        scale.range = function(_) {
            return arguments.length ? (range = slice$5.call(_), rescale()) : range.slice();
        };

        scale.rangeRound = function(_) {
            return range = slice$5.call(_), interpolate$$1 = interpolateRound, rescale();
        };

        scale.clamp = function(_) {
            return arguments.length ? (clamp = !!_, rescale()) : clamp;
        };

        scale.interpolate = function(_) {
            return arguments.length ? (interpolate$$1 = _, rescale()) : interpolate$$1;
        };

        return rescale();
    }

    function tickFormat(domain, count, specifier) {
        var start = domain[0],
            stop = domain[domain.length - 1],
            step = tickStep(start, stop, count == null ? 10 : count),
            precision;
        specifier = formatSpecifier(specifier == null ? ",f" : specifier);
        switch (specifier.type) {
            case "s": {
                var value = Math.max(Math.abs(start), Math.abs(stop));
                if (specifier.precision == null && !isNaN(precision = precisionPrefix(step, value))) specifier.precision = precision;
                return exports.formatPrefix(specifier, value);
            }
            case "":
            case "e":
            case "g":
            case "p":
            case "r": {
                if (specifier.precision == null && !isNaN(precision = precisionRound(step, Math.max(Math.abs(start), Math.abs(stop))))) specifier.precision = precision - (specifier.type === "e");
                break;
            }
            case "f":
            case "%": {
                if (specifier.precision == null && !isNaN(precision = precisionFixed(step))) specifier.precision = precision - (specifier.type === "%") * 2;
                break;
            }
        }
        return exports.format(specifier);
    }

    function linearish(scale) {
        var domain = scale.domain;

        scale.ticks = function(count) {
            var d = domain();
            return ticks(d[0], d[d.length - 1], count == null ? 10 : count);
        };

        scale.tickFormat = function(count, specifier) {
            return tickFormat(domain(), count, specifier);
        };

        scale.nice = function(count) {
            if (count == null) count = 10;

            var d = domain(),
                i0 = 0,
                i1 = d.length - 1,
                start = d[i0],
                stop = d[i1],
                step;

            if (stop < start) {
                step = start, start = stop, stop = step;
                step = i0, i0 = i1, i1 = step;
            }

            step = tickIncrement(start, stop, count);

            if (step > 0) {
                start = Math.floor(start / step) * step;
                stop = Math.ceil(stop / step) * step;
                step = tickIncrement(start, stop, count);
            } else if (step < 0) {
                start = Math.ceil(start * step) / step;
                stop = Math.floor(stop * step) / step;
                step = tickIncrement(start, stop, count);
            }

            if (step > 0) {
                d[i0] = Math.floor(start / step) * step;
                d[i1] = Math.ceil(stop / step) * step;
                domain(d);
            } else if (step < 0) {
                d[i0] = Math.ceil(start * step) / step;
                d[i1] = Math.floor(stop * step) / step;
                domain(d);
            }

            return scale;
        };

        return scale;
    }

    function linear$2() {
        var scale = continuous(deinterpolateLinear, reinterpolate);

        scale.copy = function() {
            return copy(scale, linear$2());
        };

        return linearish(scale);
    }

    function identity$6() {
        var domain = [0, 1];

        function scale(x) {
            return +x;
        }

        scale.invert = scale;

        scale.domain = scale.range = function(_) {
            return arguments.length ? (domain = map$3.call(_, number$2), scale) : domain.slice();
        };

        scale.copy = function() {
            return identity$6().domain(domain);
        };

        return linearish(scale);
    }

    function nice(domain, interval) {
        domain = domain.slice();

        var i0 = 0,
            i1 = domain.length - 1,
            x0 = domain[i0],
            x1 = domain[i1],
            t;

        if (x1 < x0) {
            t = i0, i0 = i1, i1 = t;
            t = x0, x0 = x1, x1 = t;
        }

        domain[i0] = interval.floor(x0);
        domain[i1] = interval.ceil(x1);
        return domain;
    }

    function deinterpolate(a, b) {
        return (b = Math.log(b / a))
            ? function(x) { return Math.log(x / a) / b; }
            : constant$9(b);
    }

    function reinterpolate$1(a, b) {
        return a < 0
            ? function(t) { return -Math.pow(-b, t) * Math.pow(-a, 1 - t); }
            : function(t) { return Math.pow(b, t) * Math.pow(a, 1 - t); };
    }

    function pow10(x) {
        return isFinite(x) ? +("1e" + x) : x < 0 ? 0 : x;
    }

    function powp(base) {
        return base === 10 ? pow10
            : base === Math.E ? Math.exp
                : function(x) { return Math.pow(base, x); };
    }

    function logp(base) {
        return base === Math.E ? Math.log
            : base === 10 && Math.log10
            || base === 2 && Math.log2
            || (base = Math.log(base), function(x) { return Math.log(x) / base; });
    }

    function reflect(f) {
        return function(x) {
            return -f(-x);
        };
    }

    function log$1() {
        var scale = continuous(deinterpolate, reinterpolate$1).domain([1, 10]),
            domain = scale.domain,
            base = 10,
            logs = logp(10),
            pows = powp(10);

        function rescale() {
            logs = logp(base), pows = powp(base);
            if (domain()[0] < 0) logs = reflect(logs), pows = reflect(pows);
            return scale;
        }

        scale.base = function(_) {
            return arguments.length ? (base = +_, rescale()) : base;
        };

        scale.domain = function(_) {
            return arguments.length ? (domain(_), rescale()) : domain();
        };

        scale.ticks = function(count) {
            var d = domain(),
                u = d[0],
                v = d[d.length - 1],
                r;

            if (r = v < u) i = u, u = v, v = i;

            var i = logs(u),
                j = logs(v),
                p,
                k,
                t,
                n = count == null ? 10 : +count,
                z = [];

            if (!(base % 1) && j - i < n) {
                i = Math.round(i) - 1, j = Math.round(j) + 1;
                if (u > 0) for (; i < j; ++i) {
                    for (k = 1, p = pows(i); k < base; ++k) {
                        t = p * k;
                        if (t < u) continue;
                        if (t > v) break;
                        z.push(t);
                    }
                } else for (; i < j; ++i) {
                    for (k = base - 1, p = pows(i); k >= 1; --k) {
                        t = p * k;
                        if (t < u) continue;
                        if (t > v) break;
                        z.push(t);
                    }
                }
            } else {
                z = ticks(i, j, Math.min(j - i, n)).map(pows);
            }

            return r ? z.reverse() : z;
        };

        scale.tickFormat = function(count, specifier) {
            if (specifier == null) specifier = base === 10 ? ".0e" : ",";
            if (typeof specifier !== "function") specifier = exports.format(specifier);
            if (count === Infinity) return specifier;
            if (count == null) count = 10;
            var k = Math.max(1, base * count / scale.ticks().length); // TODO fast estimate?
            return function(d) {
                var i = d / pows(Math.round(logs(d)));
                if (i * base < base - 0.5) i *= base;
                return i <= k ? specifier(d) : "";
            };
        };

        scale.nice = function() {
            return domain(nice(domain(), {
                floor: function(x) { return pows(Math.floor(logs(x))); },
                ceil: function(x) { return pows(Math.ceil(logs(x))); }
            }));
        };

        scale.copy = function() {
            return copy(scale, log$1().base(base));
        };

        return scale;
    }

    function raise$1(x, exponent) {
        return x < 0 ? -Math.pow(-x, exponent) : Math.pow(x, exponent);
    }

    function pow$1() {
        var exponent = 1,
            scale = continuous(deinterpolate, reinterpolate),
            domain = scale.domain;

        function deinterpolate(a, b) {
            return (b = raise$1(b, exponent) - (a = raise$1(a, exponent)))
                ? function(x) { return (raise$1(x, exponent) - a) / b; }
                : constant$9(b);
        }

        function reinterpolate(a, b) {
            b = raise$1(b, exponent) - (a = raise$1(a, exponent));
            return function(t) { return raise$1(a + b * t, 1 / exponent); };
        }

        scale.exponent = function(_) {
            return arguments.length ? (exponent = +_, domain(domain())) : exponent;
        };

        scale.copy = function() {
            return copy(scale, pow$1().exponent(exponent));
        };

        return linearish(scale);
    }

    function sqrt$1() {
        return pow$1().exponent(0.5);
    }

    function quantile$$1() {
        var domain = [],
            range = [],
            thresholds = [];

        function rescale() {
            var i = 0, n = Math.max(1, range.length);
            thresholds = new Array(n - 1);
            while (++i < n) thresholds[i - 1] = threshold(domain, i / n);
            return scale;
        }

        function scale(x) {
            if (!isNaN(x = +x)) return range[bisectRight(thresholds, x)];
        }

        scale.invertExtent = function(y) {
            var i = range.indexOf(y);
            return i < 0 ? [NaN, NaN] : [
                i > 0 ? thresholds[i - 1] : domain[0],
                i < thresholds.length ? thresholds[i] : domain[domain.length - 1]
            ];
        };

        scale.domain = function(_) {
            if (!arguments.length) return domain.slice();
            domain = [];
            for (var i = 0, n = _.length, d; i < n; ++i) if (d = _[i], d != null && !isNaN(d = +d)) domain.push(d);
            domain.sort(ascending);
            return rescale();
        };

        scale.range = function(_) {
            return arguments.length ? (range = slice$5.call(_), rescale()) : range.slice();
        };

        scale.quantiles = function() {
            return thresholds.slice();
        };

        scale.copy = function() {
            return quantile$$1()
                .domain(domain)
                .range(range);
        };

        return scale;
    }

    function quantize$1() {
        var x0 = 0,
            x1 = 1,
            n = 1,
            domain = [0.5],
            range = [0, 1];

        function scale(x) {
            if (x <= x) return range[bisectRight(domain, x, 0, n)];
        }

        function rescale() {
            var i = -1;
            domain = new Array(n);
            while (++i < n) domain[i] = ((i + 1) * x1 - (i - n) * x0) / (n + 1);
            return scale;
        }

        scale.domain = function(_) {
            return arguments.length ? (x0 = +_[0], x1 = +_[1], rescale()) : [x0, x1];
        };

        scale.range = function(_) {
            return arguments.length ? (n = (range = slice$5.call(_)).length - 1, rescale()) : range.slice();
        };

        scale.invertExtent = function(y) {
            var i = range.indexOf(y);
            return i < 0 ? [NaN, NaN]
                : i < 1 ? [x0, domain[0]]
                    : i >= n ? [domain[n - 1], x1]
                        : [domain[i - 1], domain[i]];
        };

        scale.copy = function() {
            return quantize$1()
                .domain([x0, x1])
                .range(range);
        };

        return linearish(scale);
    }

    function threshold$1() {
        var domain = [0.5],
            range = [0, 1],
            n = 1;

        function scale(x) {
            if (x <= x) return range[bisectRight(domain, x, 0, n)];
        }

        scale.domain = function(_) {
            return arguments.length ? (domain = slice$5.call(_), n = Math.min(domain.length, range.length - 1), scale) : domain.slice();
        };

        scale.range = function(_) {
            return arguments.length ? (range = slice$5.call(_), n = Math.min(domain.length, range.length - 1), scale) : range.slice();
        };

        scale.invertExtent = function(y) {
            var i = range.indexOf(y);
            return [domain[i - 1], domain[i]];
        };

        scale.copy = function() {
            return threshold$1()
                .domain(domain)
                .range(range);
        };

        return scale;
    }

    var t0$1 = new Date;
    var t1$1 = new Date;

    function newInterval(floori, offseti, count, field) {

        function interval(date) {
            return floori(date = new Date(+date)), date;
        }

        interval.floor = interval;

        interval.ceil = function(date) {
            return floori(date = new Date(date - 1)), offseti(date, 1), floori(date), date;
        };

        interval.round = function(date) {
            var d0 = interval(date),
                d1 = interval.ceil(date);
            return date - d0 < d1 - date ? d0 : d1;
        };

        interval.offset = function(date, step) {
            return offseti(date = new Date(+date), step == null ? 1 : Math.floor(step)), date;
        };

        interval.range = function(start, stop, step) {
            var range = [], previous;
            start = interval.ceil(start);
            step = step == null ? 1 : Math.floor(step);
            if (!(start < stop) || !(step > 0)) return range; // also handles Invalid Date
            do range.push(previous = new Date(+start)), offseti(start, step), floori(start);
            while (previous < start && start < stop);
            return range;
        };

        interval.filter = function(test) {
            return newInterval(function(date) {
                if (date >= date) while (floori(date), !test(date)) date.setTime(date - 1);
            }, function(date, step) {
                if (date >= date) {
                    if (step < 0) while (++step <= 0) {
                        while (offseti(date, -1), !test(date)) {} // eslint-disable-line no-empty
                    } else while (--step >= 0) {
                        while (offseti(date, +1), !test(date)) {} // eslint-disable-line no-empty
                    }
                }
            });
        };

        if (count) {
            interval.count = function(start, end) {
                t0$1.setTime(+start), t1$1.setTime(+end);
                floori(t0$1), floori(t1$1);
                return Math.floor(count(t0$1, t1$1));
            };

            interval.every = function(step) {
                step = Math.floor(step);
                return !isFinite(step) || !(step > 0) ? null
                    : !(step > 1) ? interval
                        : interval.filter(field
                            ? function(d) { return field(d) % step === 0; }
                            : function(d) { return interval.count(0, d) % step === 0; });
            };
        }

        return interval;
    }

    var millisecond = newInterval(function() {
        // noop
    }, function(date, step) {
        date.setTime(+date + step);
    }, function(start, end) {
        return end - start;
    });

// An optimized implementation for this simple case.
    millisecond.every = function(k) {
        k = Math.floor(k);
        if (!isFinite(k) || !(k > 0)) return null;
        if (!(k > 1)) return millisecond;
        return newInterval(function(date) {
            date.setTime(Math.floor(date / k) * k);
        }, function(date, step) {
            date.setTime(+date + step * k);
        }, function(start, end) {
            return (end - start) / k;
        });
    };

    var milliseconds = millisecond.range;

    var durationSecond$1 = 1e3;
    var durationMinute$1 = 6e4;
    var durationHour$1 = 36e5;
    var durationDay$1 = 864e5;
    var durationWeek$1 = 6048e5;

    var second = newInterval(function(date) {
        date.setTime(Math.floor(date / durationSecond$1) * durationSecond$1);
    }, function(date, step) {
        date.setTime(+date + step * durationSecond$1);
    }, function(start, end) {
        return (end - start) / durationSecond$1;
    }, function(date) {
        return date.getUTCSeconds();
    });

    var seconds = second.range;

    var minute = newInterval(function(date) {
        date.setTime(Math.floor(date / durationMinute$1) * durationMinute$1);
    }, function(date, step) {
        date.setTime(+date + step * durationMinute$1);
    }, function(start, end) {
        return (end - start) / durationMinute$1;
    }, function(date) {
        return date.getMinutes();
    });

    var minutes = minute.range;

    var hour = newInterval(function(date) {
        var offset = date.getTimezoneOffset() * durationMinute$1 % durationHour$1;
        if (offset < 0) offset += durationHour$1;
        date.setTime(Math.floor((+date - offset) / durationHour$1) * durationHour$1 + offset);
    }, function(date, step) {
        date.setTime(+date + step * durationHour$1);
    }, function(start, end) {
        return (end - start) / durationHour$1;
    }, function(date) {
        return date.getHours();
    });

    var hours = hour.range;

    var day = newInterval(function(date) {
        date.setHours(0, 0, 0, 0);
    }, function(date, step) {
        date.setDate(date.getDate() + step);
    }, function(start, end) {
        return (end - start - (end.getTimezoneOffset() - start.getTimezoneOffset()) * durationMinute$1) / durationDay$1;
    }, function(date) {
        return date.getDate() - 1;
    });

    var days = day.range;

    function weekday(i) {
        return newInterval(function(date) {
            date.setDate(date.getDate() - (date.getDay() + 7 - i) % 7);
            date.setHours(0, 0, 0, 0);
        }, function(date, step) {
            date.setDate(date.getDate() + step * 7);
        }, function(start, end) {
            return (end - start - (end.getTimezoneOffset() - start.getTimezoneOffset()) * durationMinute$1) / durationWeek$1;
        });
    }

    var sunday = weekday(0);
    var monday = weekday(1);
    var tuesday = weekday(2);
    var wednesday = weekday(3);
    var thursday = weekday(4);
    var friday = weekday(5);
    var saturday = weekday(6);

    var sundays = sunday.range;
    var mondays = monday.range;
    var tuesdays = tuesday.range;
    var wednesdays = wednesday.range;
    var thursdays = thursday.range;
    var fridays = friday.range;
    var saturdays = saturday.range;

    var month = newInterval(function(date) {
        date.setDate(1);
        date.setHours(0, 0, 0, 0);
    }, function(date, step) {
        date.setMonth(date.getMonth() + step);
    }, function(start, end) {
        return end.getMonth() - start.getMonth() + (end.getFullYear() - start.getFullYear()) * 12;
    }, function(date) {
        return date.getMonth();
    });

    var months = month.range;

    var year = newInterval(function(date) {
        date.setMonth(0, 1);
        date.setHours(0, 0, 0, 0);
    }, function(date, step) {
        date.setFullYear(date.getFullYear() + step);
    }, function(start, end) {
        return end.getFullYear() - start.getFullYear();
    }, function(date) {
        return date.getFullYear();
    });

// An optimized implementation for this simple case.
    year.every = function(k) {
        return !isFinite(k = Math.floor(k)) || !(k > 0) ? null : newInterval(function(date) {
            date.setFullYear(Math.floor(date.getFullYear() / k) * k);
            date.setMonth(0, 1);
            date.setHours(0, 0, 0, 0);
        }, function(date, step) {
            date.setFullYear(date.getFullYear() + step * k);
        });
    };

    var years = year.range;

    var utcMinute = newInterval(function(date) {
        date.setUTCSeconds(0, 0);
    }, function(date, step) {
        date.setTime(+date + step * durationMinute$1);
    }, function(start, end) {
        return (end - start) / durationMinute$1;
    }, function(date) {
        return date.getUTCMinutes();
    });

    var utcMinutes = utcMinute.range;

    var utcHour = newInterval(function(date) {
        date.setUTCMinutes(0, 0, 0);
    }, function(date, step) {
        date.setTime(+date + step * durationHour$1);
    }, function(start, end) {
        return (end - start) / durationHour$1;
    }, function(date) {
        return date.getUTCHours();
    });

    var utcHours = utcHour.range;

    var utcDay = newInterval(function(date) {
        date.setUTCHours(0, 0, 0, 0);
    }, function(date, step) {
        date.setUTCDate(date.getUTCDate() + step);
    }, function(start, end) {
        return (end - start) / durationDay$1;
    }, function(date) {
        return date.getUTCDate() - 1;
    });

    var utcDays = utcDay.range;

    function utcWeekday(i) {
        return newInterval(function(date) {
            date.setUTCDate(date.getUTCDate() - (date.getUTCDay() + 7 - i) % 7);
            date.setUTCHours(0, 0, 0, 0);
        }, function(date, step) {
            date.setUTCDate(date.getUTCDate() + step * 7);
        }, function(start, end) {
            return (end - start) / durationWeek$1;
        });
    }

    var utcSunday = utcWeekday(0);
    var utcMonday = utcWeekday(1);
    var utcTuesday = utcWeekday(2);
    var utcWednesday = utcWeekday(3);
    var utcThursday = utcWeekday(4);
    var utcFriday = utcWeekday(5);
    var utcSaturday = utcWeekday(6);

    var utcSundays = utcSunday.range;
    var utcMondays = utcMonday.range;
    var utcTuesdays = utcTuesday.range;
    var utcWednesdays = utcWednesday.range;
    var utcThursdays = utcThursday.range;
    var utcFridays = utcFriday.range;
    var utcSaturdays = utcSaturday.range;

    var utcMonth = newInterval(function(date) {
        date.setUTCDate(1);
        date.setUTCHours(0, 0, 0, 0);
    }, function(date, step) {
        date.setUTCMonth(date.getUTCMonth() + step);
    }, function(start, end) {
        return end.getUTCMonth() - start.getUTCMonth() + (end.getUTCFullYear() - start.getUTCFullYear()) * 12;
    }, function(date) {
        return date.getUTCMonth();
    });

    var utcMonths = utcMonth.range;

    var utcYear = newInterval(function(date) {
        date.setUTCMonth(0, 1);
        date.setUTCHours(0, 0, 0, 0);
    }, function(date, step) {
        date.setUTCFullYear(date.getUTCFullYear() + step);
    }, function(start, end) {
        return end.getUTCFullYear() - start.getUTCFullYear();
    }, function(date) {
        return date.getUTCFullYear();
    });

// An optimized implementation for this simple case.
    utcYear.every = function(k) {
        return !isFinite(k = Math.floor(k)) || !(k > 0) ? null : newInterval(function(date) {
            date.setUTCFullYear(Math.floor(date.getUTCFullYear() / k) * k);
            date.setUTCMonth(0, 1);
            date.setUTCHours(0, 0, 0, 0);
        }, function(date, step) {
            date.setUTCFullYear(date.getUTCFullYear() + step * k);
        });
    };

    var utcYears = utcYear.range;

    function localDate(d) {
        if (0 <= d.y && d.y < 100) {
            var date = new Date(-1, d.m, d.d, d.H, d.M, d.S, d.L);
            date.setFullYear(d.y);
            return date;
        }
        return new Date(d.y, d.m, d.d, d.H, d.M, d.S, d.L);
    }

    function utcDate(d) {
        if (0 <= d.y && d.y < 100) {
            var date = new Date(Date.UTC(-1, d.m, d.d, d.H, d.M, d.S, d.L));
            date.setUTCFullYear(d.y);
            return date;
        }
        return new Date(Date.UTC(d.y, d.m, d.d, d.H, d.M, d.S, d.L));
    }

    function newYear(y) {
        return {y: y, m: 0, d: 1, H: 0, M: 0, S: 0, L: 0};
    }

    function formatLocale$1(locale) {
        var locale_dateTime = locale.dateTime,
            locale_date = locale.date,
            locale_time = locale.time,
            locale_periods = locale.periods,
            locale_weekdays = locale.days,
            locale_shortWeekdays = locale.shortDays,
            locale_months = locale.months,
            locale_shortMonths = locale.shortMonths;

        var periodRe = formatRe(locale_periods),
            periodLookup = formatLookup(locale_periods),
            weekdayRe = formatRe(locale_weekdays),
            weekdayLookup = formatLookup(locale_weekdays),
            shortWeekdayRe = formatRe(locale_shortWeekdays),
            shortWeekdayLookup = formatLookup(locale_shortWeekdays),
            monthRe = formatRe(locale_months),
            monthLookup = formatLookup(locale_months),
            shortMonthRe = formatRe(locale_shortMonths),
            shortMonthLookup = formatLookup(locale_shortMonths);

        var formats = {
            "a": formatShortWeekday,
            "A": formatWeekday,
            "b": formatShortMonth,
            "B": formatMonth,
            "c": null,
            "d": formatDayOfMonth,
            "e": formatDayOfMonth,
            "f": formatMicroseconds,
            "H": formatHour24,
            "I": formatHour12,
            "j": formatDayOfYear,
            "L": formatMilliseconds,
            "m": formatMonthNumber,
            "M": formatMinutes,
            "p": formatPeriod,
            "Q": formatUnixTimestamp,
            "s": formatUnixTimestampSeconds,
            "S": formatSeconds,
            "u": formatWeekdayNumberMonday,
            "U": formatWeekNumberSunday,
            "V": formatWeekNumberISO,
            "w": formatWeekdayNumberSunday,
            "W": formatWeekNumberMonday,
            "x": null,
            "X": null,
            "y": formatYear,
            "Y": formatFullYear,
            "Z": formatZone,
            "%": formatLiteralPercent
        };

        var utcFormats = {
            "a": formatUTCShortWeekday,
            "A": formatUTCWeekday,
            "b": formatUTCShortMonth,
            "B": formatUTCMonth,
            "c": null,
            "d": formatUTCDayOfMonth,
            "e": formatUTCDayOfMonth,
            "f": formatUTCMicroseconds,
            "H": formatUTCHour24,
            "I": formatUTCHour12,
            "j": formatUTCDayOfYear,
            "L": formatUTCMilliseconds,
            "m": formatUTCMonthNumber,
            "M": formatUTCMinutes,
            "p": formatUTCPeriod,
            "Q": formatUnixTimestamp,
            "s": formatUnixTimestampSeconds,
            "S": formatUTCSeconds,
            "u": formatUTCWeekdayNumberMonday,
            "U": formatUTCWeekNumberSunday,
            "V": formatUTCWeekNumberISO,
            "w": formatUTCWeekdayNumberSunday,
            "W": formatUTCWeekNumberMonday,
            "x": null,
            "X": null,
            "y": formatUTCYear,
            "Y": formatUTCFullYear,
            "Z": formatUTCZone,
            "%": formatLiteralPercent
        };

        var parses = {
            "a": parseShortWeekday,
            "A": parseWeekday,
            "b": parseShortMonth,
            "B": parseMonth,
            "c": parseLocaleDateTime,
            "d": parseDayOfMonth,
            "e": parseDayOfMonth,
            "f": parseMicroseconds,
            "H": parseHour24,
            "I": parseHour24,
            "j": parseDayOfYear,
            "L": parseMilliseconds,
            "m": parseMonthNumber,
            "M": parseMinutes,
            "p": parsePeriod,
            "Q": parseUnixTimestamp,
            "s": parseUnixTimestampSeconds,
            "S": parseSeconds,
            "u": parseWeekdayNumberMonday,
            "U": parseWeekNumberSunday,
            "V": parseWeekNumberISO,
            "w": parseWeekdayNumberSunday,
            "W": parseWeekNumberMonday,
            "x": parseLocaleDate,
            "X": parseLocaleTime,
            "y": parseYear,
            "Y": parseFullYear,
            "Z": parseZone,
            "%": parseLiteralPercent
        };

        // These recursive directive definitions must be deferred.
        formats.x = newFormat(locale_date, formats);
        formats.X = newFormat(locale_time, formats);
        formats.c = newFormat(locale_dateTime, formats);
        utcFormats.x = newFormat(locale_date, utcFormats);
        utcFormats.X = newFormat(locale_time, utcFormats);
        utcFormats.c = newFormat(locale_dateTime, utcFormats);

        function newFormat(specifier, formats) {
            return function(date) {
                var string = [],
                    i = -1,
                    j = 0,
                    n = specifier.length,
                    c,
                    pad,
                    format;

                if (!(date instanceof Date)) date = new Date(+date);

                while (++i < n) {
                    if (specifier.charCodeAt(i) === 37) {
                        string.push(specifier.slice(j, i));
                        if ((pad = pads[c = specifier.charAt(++i)]) != null) c = specifier.charAt(++i);
                        else pad = c === "e" ? " " : "0";
                        if (format = formats[c]) c = format(date, pad);
                        string.push(c);
                        j = i + 1;
                    }
                }

                string.push(specifier.slice(j, i));
                return string.join("");
            };
        }

        function newParse(specifier, newDate) {
            return function(string) {
                var d = newYear(1900),
                    i = parseSpecifier(d, specifier, string += "", 0),
                    week, day$$1;
                if (i != string.length) return null;

                // If a UNIX timestamp is specified, return it.
                if ("Q" in d) return new Date(d.Q);

                // The am-pm flag is 0 for AM, and 1 for PM.
                if ("p" in d) d.H = d.H % 12 + d.p * 12;

                // Convert day-of-week and week-of-year to day-of-year.
                if ("V" in d) {
                    if (d.V < 1 || d.V > 53) return null;
                    if (!("w" in d)) d.w = 1;
                    if ("Z" in d) {
                        week = utcDate(newYear(d.y)), day$$1 = week.getUTCDay();
                        week = day$$1 > 4 || day$$1 === 0 ? utcMonday.ceil(week) : utcMonday(week);
                        week = utcDay.offset(week, (d.V - 1) * 7);
                        d.y = week.getUTCFullYear();
                        d.m = week.getUTCMonth();
                        d.d = week.getUTCDate() + (d.w + 6) % 7;
                    } else {
                        week = newDate(newYear(d.y)), day$$1 = week.getDay();
                        week = day$$1 > 4 || day$$1 === 0 ? monday.ceil(week) : monday(week);
                        week = day.offset(week, (d.V - 1) * 7);
                        d.y = week.getFullYear();
                        d.m = week.getMonth();
                        d.d = week.getDate() + (d.w + 6) % 7;
                    }
                } else if ("W" in d || "U" in d) {
                    if (!("w" in d)) d.w = "u" in d ? d.u % 7 : "W" in d ? 1 : 0;
                    day$$1 = "Z" in d ? utcDate(newYear(d.y)).getUTCDay() : newDate(newYear(d.y)).getDay();
                    d.m = 0;
                    d.d = "W" in d ? (d.w + 6) % 7 + d.W * 7 - (day$$1 + 5) % 7 : d.w + d.U * 7 - (day$$1 + 6) % 7;
                }

                // If a time zone is specified, all fields are interpreted as UTC and then
                // offset according to the specified time zone.
                if ("Z" in d) {
                    d.H += d.Z / 100 | 0;
                    d.M += d.Z % 100;
                    return utcDate(d);
                }

                // Otherwise, all fields are in local time.
                return newDate(d);
            };
        }

        function parseSpecifier(d, specifier, string, j) {
            var i = 0,
                n = specifier.length,
                m = string.length,
                c,
                parse;

            while (i < n) {
                if (j >= m) return -1;
                c = specifier.charCodeAt(i++);
                if (c === 37) {
                    c = specifier.charAt(i++);
                    parse = parses[c in pads ? specifier.charAt(i++) : c];
                    if (!parse || ((j = parse(d, string, j)) < 0)) return -1;
                } else if (c != string.charCodeAt(j++)) {
                    return -1;
                }
            }

            return j;
        }

        function parsePeriod(d, string, i) {
            var n = periodRe.exec(string.slice(i));
            return n ? (d.p = periodLookup[n[0].toLowerCase()], i + n[0].length) : -1;
        }

        function parseShortWeekday(d, string, i) {
            var n = shortWeekdayRe.exec(string.slice(i));
            return n ? (d.w = shortWeekdayLookup[n[0].toLowerCase()], i + n[0].length) : -1;
        }

        function parseWeekday(d, string, i) {
            var n = weekdayRe.exec(string.slice(i));
            return n ? (d.w = weekdayLookup[n[0].toLowerCase()], i + n[0].length) : -1;
        }

        function parseShortMonth(d, string, i) {
            var n = shortMonthRe.exec(string.slice(i));
            return n ? (d.m = shortMonthLookup[n[0].toLowerCase()], i + n[0].length) : -1;
        }

        function parseMonth(d, string, i) {
            var n = monthRe.exec(string.slice(i));
            return n ? (d.m = monthLookup[n[0].toLowerCase()], i + n[0].length) : -1;
        }

        function parseLocaleDateTime(d, string, i) {
            return parseSpecifier(d, locale_dateTime, string, i);
        }

        function parseLocaleDate(d, string, i) {
            return parseSpecifier(d, locale_date, string, i);
        }

        function parseLocaleTime(d, string, i) {
            return parseSpecifier(d, locale_time, string, i);
        }

        function formatShortWeekday(d) {
            return locale_shortWeekdays[d.getDay()];
        }

        function formatWeekday(d) {
            return locale_weekdays[d.getDay()];
        }

        function formatShortMonth(d) {
            return locale_shortMonths[d.getMonth()];
        }

        function formatMonth(d) {
            return locale_months[d.getMonth()];
        }

        function formatPeriod(d) {
            return locale_periods[+(d.getHours() >= 12)];
        }

        function formatUTCShortWeekday(d) {
            return locale_shortWeekdays[d.getUTCDay()];
        }

        function formatUTCWeekday(d) {
            return locale_weekdays[d.getUTCDay()];
        }

        function formatUTCShortMonth(d) {
            return locale_shortMonths[d.getUTCMonth()];
        }

        function formatUTCMonth(d) {
            return locale_months[d.getUTCMonth()];
        }

        function formatUTCPeriod(d) {
            return locale_periods[+(d.getUTCHours() >= 12)];
        }

        return {
            format: function(specifier) {
                var f = newFormat(specifier += "", formats);
                f.toString = function() { return specifier; };
                return f;
            },
            parse: function(specifier) {
                var p = newParse(specifier += "", localDate);
                p.toString = function() { return specifier; };
                return p;
            },
            utcFormat: function(specifier) {
                var f = newFormat(specifier += "", utcFormats);
                f.toString = function() { return specifier; };
                return f;
            },
            utcParse: function(specifier) {
                var p = newParse(specifier, utcDate);
                p.toString = function() { return specifier; };
                return p;
            }
        };
    }

    var pads = {"-": "", "_": " ", "0": "0"};
    var numberRe = /^\s*\d+/;
    var percentRe = /^%/;
    var requoteRe = /[\\^$*+?|[\]().{}]/g;

    function pad(value, fill, width) {
        var sign = value < 0 ? "-" : "",
            string = (sign ? -value : value) + "",
            length = string.length;
        return sign + (length < width ? new Array(width - length + 1).join(fill) + string : string);
    }

    function requote(s) {
        return s.replace(requoteRe, "\\$&");
    }

    function formatRe(names) {
        return new RegExp("^(?:" + names.map(requote).join("|") + ")", "i");
    }

    function formatLookup(names) {
        var map = {}, i = -1, n = names.length;
        while (++i < n) map[names[i].toLowerCase()] = i;
        return map;
    }

    function parseWeekdayNumberSunday(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 1));
        return n ? (d.w = +n[0], i + n[0].length) : -1;
    }

    function parseWeekdayNumberMonday(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 1));
        return n ? (d.u = +n[0], i + n[0].length) : -1;
    }

    function parseWeekNumberSunday(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 2));
        return n ? (d.U = +n[0], i + n[0].length) : -1;
    }

    function parseWeekNumberISO(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 2));
        return n ? (d.V = +n[0], i + n[0].length) : -1;
    }

    function parseWeekNumberMonday(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 2));
        return n ? (d.W = +n[0], i + n[0].length) : -1;
    }

    function parseFullYear(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 4));
        return n ? (d.y = +n[0], i + n[0].length) : -1;
    }

    function parseYear(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 2));
        return n ? (d.y = +n[0] + (+n[0] > 68 ? 1900 : 2000), i + n[0].length) : -1;
    }

    function parseZone(d, string, i) {
        var n = /^(Z)|([+-]\d\d)(?::?(\d\d))?/.exec(string.slice(i, i + 6));
        return n ? (d.Z = n[1] ? 0 : -(n[2] + (n[3] || "00")), i + n[0].length) : -1;
    }

    function parseMonthNumber(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 2));
        return n ? (d.m = n[0] - 1, i + n[0].length) : -1;
    }

    function parseDayOfMonth(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 2));
        return n ? (d.d = +n[0], i + n[0].length) : -1;
    }

    function parseDayOfYear(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 3));
        return n ? (d.m = 0, d.d = +n[0], i + n[0].length) : -1;
    }

    function parseHour24(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 2));
        return n ? (d.H = +n[0], i + n[0].length) : -1;
    }

    function parseMinutes(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 2));
        return n ? (d.M = +n[0], i + n[0].length) : -1;
    }

    function parseSeconds(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 2));
        return n ? (d.S = +n[0], i + n[0].length) : -1;
    }

    function parseMilliseconds(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 3));
        return n ? (d.L = +n[0], i + n[0].length) : -1;
    }

    function parseMicroseconds(d, string, i) {
        var n = numberRe.exec(string.slice(i, i + 6));
        return n ? (d.L = Math.floor(n[0] / 1000), i + n[0].length) : -1;
    }

    function parseLiteralPercent(d, string, i) {
        var n = percentRe.exec(string.slice(i, i + 1));
        return n ? i + n[0].length : -1;
    }

    function parseUnixTimestamp(d, string, i) {
        var n = numberRe.exec(string.slice(i));
        return n ? (d.Q = +n[0], i + n[0].length) : -1;
    }

    function parseUnixTimestampSeconds(d, string, i) {
        var n = numberRe.exec(string.slice(i));
        return n ? (d.Q = (+n[0]) * 1000, i + n[0].length) : -1;
    }

    function formatDayOfMonth(d, p) {
        return pad(d.getDate(), p, 2);
    }

    function formatHour24(d, p) {
        return pad(d.getHours(), p, 2);
    }

    function formatHour12(d, p) {
        return pad(d.getHours() % 12 || 12, p, 2);
    }

    function formatDayOfYear(d, p) {
        return pad(1 + day.count(year(d), d), p, 3);
    }

    function formatMilliseconds(d, p) {
        return pad(d.getMilliseconds(), p, 3);
    }

    function formatMicroseconds(d, p) {
        return formatMilliseconds(d, p) + "000";
    }

    function formatMonthNumber(d, p) {
        return pad(d.getMonth() + 1, p, 2);
    }

    function formatMinutes(d, p) {
        return pad(d.getMinutes(), p, 2);
    }

    function formatSeconds(d, p) {
        return pad(d.getSeconds(), p, 2);
    }

    function formatWeekdayNumberMonday(d) {
        var day$$1 = d.getDay();
        return day$$1 === 0 ? 7 : day$$1;
    }

    function formatWeekNumberSunday(d, p) {
        return pad(sunday.count(year(d), d), p, 2);
    }

    function formatWeekNumberISO(d, p) {
        var day$$1 = d.getDay();
        d = (day$$1 >= 4 || day$$1 === 0) ? thursday(d) : thursday.ceil(d);
        return pad(thursday.count(year(d), d) + (year(d).getDay() === 4), p, 2);
    }

    function formatWeekdayNumberSunday(d) {
        return d.getDay();
    }

    function formatWeekNumberMonday(d, p) {
        return pad(monday.count(year(d), d), p, 2);
    }

    function formatYear(d, p) {
        return pad(d.getFullYear() % 100, p, 2);
    }

    function formatFullYear(d, p) {
        return pad(d.getFullYear() % 10000, p, 4);
    }

    function formatZone(d) {
        var z = d.getTimezoneOffset();
        return (z > 0 ? "-" : (z *= -1, "+"))
            + pad(z / 60 | 0, "0", 2)
            + pad(z % 60, "0", 2);
    }

    function formatUTCDayOfMonth(d, p) {
        return pad(d.getUTCDate(), p, 2);
    }

    function formatUTCHour24(d, p) {
        return pad(d.getUTCHours(), p, 2);
    }

    function formatUTCHour12(d, p) {
        return pad(d.getUTCHours() % 12 || 12, p, 2);
    }

    function formatUTCDayOfYear(d, p) {
        return pad(1 + utcDay.count(utcYear(d), d), p, 3);
    }

    function formatUTCMilliseconds(d, p) {
        return pad(d.getUTCMilliseconds(), p, 3);
    }

    function formatUTCMicroseconds(d, p) {
        return formatUTCMilliseconds(d, p) + "000";
    }

    function formatUTCMonthNumber(d, p) {
        return pad(d.getUTCMonth() + 1, p, 2);
    }

    function formatUTCMinutes(d, p) {
        return pad(d.getUTCMinutes(), p, 2);
    }

    function formatUTCSeconds(d, p) {
        return pad(d.getUTCSeconds(), p, 2);
    }

    function formatUTCWeekdayNumberMonday(d) {
        var dow = d.getUTCDay();
        return dow === 0 ? 7 : dow;
    }

    function formatUTCWeekNumberSunday(d, p) {
        return pad(utcSunday.count(utcYear(d), d), p, 2);
    }

    function formatUTCWeekNumberISO(d, p) {
        var day$$1 = d.getUTCDay();
        d = (day$$1 >= 4 || day$$1 === 0) ? utcThursday(d) : utcThursday.ceil(d);
        return pad(utcThursday.count(utcYear(d), d) + (utcYear(d).getUTCDay() === 4), p, 2);
    }

    function formatUTCWeekdayNumberSunday(d) {
        return d.getUTCDay();
    }

    function formatUTCWeekNumberMonday(d, p) {
        return pad(utcMonday.count(utcYear(d), d), p, 2);
    }

    function formatUTCYear(d, p) {
        return pad(d.getUTCFullYear() % 100, p, 2);
    }

    function formatUTCFullYear(d, p) {
        return pad(d.getUTCFullYear() % 10000, p, 4);
    }

    function formatUTCZone() {
        return "+0000";
    }

    function formatLiteralPercent() {
        return "%";
    }

    function formatUnixTimestamp(d) {
        return +d;
    }

    function formatUnixTimestampSeconds(d) {
        return Math.floor(+d / 1000);
    }

    var locale$1;





    defaultLocale$1({
        dateTime: "%x, %X",
        date: "%-m/%-d/%Y",
        time: "%-I:%M:%S %p",
        periods: ["AM", "PM"],
        days: ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"],
        shortDays: ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"],
        months: ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"],
        shortMonths: ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
    });

    function defaultLocale$1(definition) {
        locale$1 = formatLocale$1(definition);
        exports.timeFormat = locale$1.format;
        exports.timeParse = locale$1.parse;
        exports.utcFormat = locale$1.utcFormat;
        exports.utcParse = locale$1.utcParse;
        return locale$1;
    }

    var isoSpecifier = "%Y-%m-%dT%H:%M:%S.%LZ";

    function formatIsoNative(date) {
        return date.toISOString();
    }

    var formatIso = Date.prototype.toISOString
        ? formatIsoNative
        : exports.utcFormat(isoSpecifier);

    function parseIsoNative(string) {
        var date = new Date(string);
        return isNaN(date) ? null : date;
    }

    var parseIso = +new Date("2000-01-01T00:00:00.000Z")
        ? parseIsoNative
        : exports.utcParse(isoSpecifier);

    var durationSecond = 1000;
    var durationMinute = durationSecond * 60;
    var durationHour = durationMinute * 60;
    var durationDay = durationHour * 24;
    var durationWeek = durationDay * 7;
    var durationMonth = durationDay * 30;
    var durationYear = durationDay * 365;

    function date$1(t) {
        return new Date(t);
    }

    function number$3(t) {
        return t instanceof Date ? +t : +new Date(+t);
    }

    function calendar(year$$1, month$$1, week, day$$1, hour$$1, minute$$1, second$$1, millisecond$$1, format) {
        var scale = continuous(deinterpolateLinear, reinterpolate),
            invert = scale.invert,
            domain = scale.domain;

        var formatMillisecond = format(".%L"),
            formatSecond = format(":%S"),
            formatMinute = format("%I:%M"),
            formatHour = format("%I %p"),
            formatDay = format("%a %d"),
            formatWeek = format("%b %d"),
            formatMonth = format("%B"),
            formatYear = format("%Y");

        var tickIntervals = [
            [second$$1,  1,      durationSecond],
            [second$$1,  5,  5 * durationSecond],
            [second$$1, 15, 15 * durationSecond],
            [second$$1, 30, 30 * durationSecond],
            [minute$$1,  1,      durationMinute],
            [minute$$1,  5,  5 * durationMinute],
            [minute$$1, 15, 15 * durationMinute],
            [minute$$1, 30, 30 * durationMinute],
            [  hour$$1,  1,      durationHour  ],
            [  hour$$1,  3,  3 * durationHour  ],
            [  hour$$1,  6,  6 * durationHour  ],
            [  hour$$1, 12, 12 * durationHour  ],
            [   day$$1,  1,      durationDay   ],
            [   day$$1,  2,  2 * durationDay   ],
            [  week,  1,      durationWeek  ],
            [ month$$1,  1,      durationMonth ],
            [ month$$1,  3,  3 * durationMonth ],
            [  year$$1,  1,      durationYear  ]
        ];

        function tickFormat(date) {
            return (second$$1(date) < date ? formatMillisecond
                : minute$$1(date) < date ? formatSecond
                    : hour$$1(date) < date ? formatMinute
                        : day$$1(date) < date ? formatHour
                            : month$$1(date) < date ? (week(date) < date ? formatDay : formatWeek)
                                : year$$1(date) < date ? formatMonth
                                    : formatYear)(date);
        }

        function tickInterval(interval, start, stop, step) {
            if (interval == null) interval = 10;

            // If a desired tick count is specified, pick a reasonable tick interval
            // based on the extent of the domain and a rough estimate of tick size.
            // Otherwise, assume interval is already a time interval and use it.
            if (typeof interval === "number") {
                var target = Math.abs(stop - start) / interval,
                    i = bisector(function(i) { return i[2]; }).right(tickIntervals, target);
                if (i === tickIntervals.length) {
                    step = tickStep(start / durationYear, stop / durationYear, interval);
                    interval = year$$1;
                } else if (i) {
                    i = tickIntervals[target / tickIntervals[i - 1][2] < tickIntervals[i][2] / target ? i - 1 : i];
                    step = i[1];
                    interval = i[0];
                } else {
                    step = Math.max(tickStep(start, stop, interval), 1);
                    interval = millisecond$$1;
                }
            }

            return step == null ? interval : interval.every(step);
        }

        scale.invert = function(y) {
            return new Date(invert(y));
        };

        scale.domain = function(_) {
            return arguments.length ? domain(map$3.call(_, number$3)) : domain().map(date$1);
        };

        scale.ticks = function(interval, step) {
            var d = domain(),
                t0 = d[0],
                t1 = d[d.length - 1],
                r = t1 < t0,
                t;
            if (r) t = t0, t0 = t1, t1 = t;
            t = tickInterval(interval, t0, t1, step);
            t = t ? t.range(t0, t1 + 1) : []; // inclusive stop
            return r ? t.reverse() : t;
        };

        scale.tickFormat = function(count, specifier) {
            return specifier == null ? tickFormat : format(specifier);
        };

        scale.nice = function(interval, step) {
            var d = domain();
            return (interval = tickInterval(interval, d[0], d[d.length - 1], step))
                ? domain(nice(d, interval))
                : scale;
        };

        scale.copy = function() {
            return copy(scale, calendar(year$$1, month$$1, week, day$$1, hour$$1, minute$$1, second$$1, millisecond$$1, format));
        };

        return scale;
    }

    function time() {
        return calendar(year, month, sunday, day, hour, minute, second, millisecond, exports.timeFormat).domain([new Date(2000, 0, 1), new Date(2000, 0, 2)]);
    }

    function utcTime() {
        return calendar(utcYear, utcMonth, utcSunday, utcDay, utcHour, utcMinute, second, millisecond, exports.utcFormat).domain([Date.UTC(2000, 0, 1), Date.UTC(2000, 0, 2)]);
    }

    function colors(s) {
        return s.match(/.{6}/g).map(function(x) {
            return "#" + x;
        });
    }

    var category10 = colors("1f77b4ff7f0e2ca02cd627289467bd8c564be377c27f7f7fbcbd2217becf");

    var category20b = colors("393b795254a36b6ecf9c9ede6379398ca252b5cf6bcedb9c8c6d31bd9e39e7ba52e7cb94843c39ad494ad6616be7969c7b4173a55194ce6dbdde9ed6");

    var category20c = colors("3182bd6baed69ecae1c6dbefe6550dfd8d3cfdae6bfdd0a231a35474c476a1d99bc7e9c0756bb19e9ac8bcbddcdadaeb636363969696bdbdbdd9d9d9");

    var category20 = colors("1f77b4aec7e8ff7f0effbb782ca02c98df8ad62728ff98969467bdc5b0d58c564bc49c94e377c2f7b6d27f7f7fc7c7c7bcbd22dbdb8d17becf9edae5");

    var cubehelix$3 = cubehelixLong(cubehelix(300, 0.5, 0.0), cubehelix(-240, 0.5, 1.0));

    var warm = cubehelixLong(cubehelix(-100, 0.75, 0.35), cubehelix(80, 1.50, 0.8));

    var cool = cubehelixLong(cubehelix(260, 0.75, 0.35), cubehelix(80, 1.50, 0.8));

    var rainbow = cubehelix();

    function rainbow$1(t) {
        if (t < 0 || t > 1) t -= Math.floor(t);
        var ts = Math.abs(t - 0.5);
        rainbow.h = 360 * t - 100;
        rainbow.s = 1.5 - 1.5 * ts;
        rainbow.l = 0.8 - 0.9 * ts;
        return rainbow + "";
    }

    function ramp(range) {
        var n = range.length;
        return function(t) {
            return range[Math.max(0, Math.min(n - 1, Math.floor(t * n)))];
        };
    }

    var viridis = ramp(colors("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"));

    var magma = ramp(colors("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"));

    var inferno = ramp(colors("00000401000501010601010802010a02020c02020e03021004031204031405041706041907051b08051d09061f0a07220b07240c08260d08290e092b10092d110a30120a32140b34150b37160b39180c3c190c3e1b0c411c0c431e0c451f0c48210c4a230c4c240c4f260c51280b53290b552b0b572d0b592f0a5b310a5c320a5e340a5f3609613809623909633b09643d09653e0966400a67420a68440a68450a69470b6a490b6a4a0c6b4c0c6b4d0d6c4f0d6c510e6c520e6d540f6d550f6d57106e59106e5a116e5c126e5d126e5f136e61136e62146e64156e65156e67166e69166e6a176e6c186e6d186e6f196e71196e721a6e741a6e751b6e771c6d781c6d7a1d6d7c1d6d7d1e6d7f1e6c801f6c82206c84206b85216b87216b88226a8a226a8c23698d23698f24699025689225689326679526679727669827669a28659b29649d29649f2a63a02a63a22b62a32c61a52c60a62d60a82e5fa92e5eab2f5ead305dae305cb0315bb1325ab3325ab43359b63458b73557b93556ba3655bc3754bd3853bf3952c03a51c13a50c33b4fc43c4ec63d4dc73e4cc83f4bca404acb4149cc4248ce4347cf4446d04545d24644d34743d44842d54a41d74b3fd84c3ed94d3dda4e3cdb503bdd513ade5238df5337e05536e15635e25734e35933e45a31e55c30e65d2fe75e2ee8602de9612bea632aeb6429eb6628ec6726ed6925ee6a24ef6c23ef6e21f06f20f1711ff1731df2741cf3761bf37819f47918f57b17f57d15f67e14f68013f78212f78410f8850ff8870ef8890cf98b0bf98c0af98e09fa9008fa9207fa9407fb9606fb9706fb9906fb9b06fb9d07fc9f07fca108fca309fca50afca60cfca80dfcaa0ffcac11fcae12fcb014fcb216fcb418fbb61afbb81dfbba1ffbbc21fbbe23fac026fac228fac42afac62df9c72ff9c932f9cb35f8cd37f8cf3af7d13df7d340f6d543f6d746f5d949f5db4cf4dd4ff4df53f4e156f3e35af3e55df2e661f2e865f2ea69f1ec6df1ed71f1ef75f1f179f2f27df2f482f3f586f3f68af4f88ef5f992f6fa96f8fb9af9fc9dfafda1fcffa4"));

    var plasma = ramp(colors("0d088710078813078916078a19068c1b068d1d068e20068f2206902406912605912805922a05932c05942e05952f059631059733059735049837049938049a3a049a3c049b3e049c3f049c41049d43039e44039e46039f48039f4903a04b03a14c02a14e02a25002a25102a35302a35502a45601a45801a45901a55b01a55c01a65e01a66001a66100a76300a76400a76600a76700a86900a86a00a86c00a86e00a86f00a87100a87201a87401a87501a87701a87801a87a02a87b02a87d03a87e03a88004a88104a78305a78405a78606a68707a68808a68a09a58b0aa58d0ba58e0ca48f0da4910ea3920fa39410a29511a19613a19814a099159f9a169f9c179e9d189d9e199da01a9ca11b9ba21d9aa31e9aa51f99a62098a72197a82296aa2395ab2494ac2694ad2793ae2892b02991b12a90b22b8fb32c8eb42e8db52f8cb6308bb7318ab83289ba3388bb3488bc3587bd3786be3885bf3984c03a83c13b82c23c81c33d80c43e7fc5407ec6417dc7427cc8437bc9447aca457acb4679cc4778cc4977cd4a76ce4b75cf4c74d04d73d14e72d24f71d35171d45270d5536fd5546ed6556dd7566cd8576bd9586ada5a6ada5b69db5c68dc5d67dd5e66de5f65de6164df6263e06363e16462e26561e26660e3685fe4695ee56a5de56b5de66c5ce76e5be76f5ae87059e97158e97257ea7457eb7556eb7655ec7754ed7953ed7a52ee7b51ef7c51ef7e50f07f4ff0804ef1814df1834cf2844bf3854bf3874af48849f48948f58b47f58c46f68d45f68f44f79044f79143f79342f89441f89540f9973ff9983ef99a3efa9b3dfa9c3cfa9e3bfb9f3afba139fba238fca338fca537fca636fca835fca934fdab33fdac33fdae32fdaf31fdb130fdb22ffdb42ffdb52efeb72dfeb82cfeba2cfebb2bfebd2afebe2afec029fdc229fdc328fdc527fdc627fdc827fdca26fdcb26fccd25fcce25fcd025fcd225fbd324fbd524fbd724fad824fada24f9dc24f9dd25f8df25f8e125f7e225f7e425f6e626f6e826f5e926f5eb27f4ed27f3ee27f3f027f2f227f1f426f1f525f0f724f0f921"));

    function sequential(interpolator) {
        var x0 = 0,
            x1 = 1,
            clamp = false;

        function scale(x) {
            var t = (x - x0) / (x1 - x0);
            return interpolator(clamp ? Math.max(0, Math.min(1, t)) : t);
        }

        scale.domain = function(_) {
            return arguments.length ? (x0 = +_[0], x1 = +_[1], scale) : [x0, x1];
        };

        scale.clamp = function(_) {
            return arguments.length ? (clamp = !!_, scale) : clamp;
        };

        scale.interpolator = function(_) {
            return arguments.length ? (interpolator = _, scale) : interpolator;
        };

        scale.copy = function() {
            return sequential(interpolator).domain([x0, x1]).clamp(clamp);
        };

        return linearish(scale);
    }

    function constant$10(x) {
        return function constant() {
            return x;
        };
    }

    var abs$1 = Math.abs;
    var atan2$1 = Math.atan2;
    var cos$2 = Math.cos;
    var max$2 = Math.max;
    var min$1 = Math.min;
    var sin$2 = Math.sin;
    var sqrt$2 = Math.sqrt;

    var epsilon$3 = 1e-12;
    var pi$4 = Math.PI;
    var halfPi$3 = pi$4 / 2;
    var tau$4 = 2 * pi$4;

    function acos$1(x) {
        return x > 1 ? 0 : x < -1 ? pi$4 : Math.acos(x);
    }

    function asin$1(x) {
        return x >= 1 ? halfPi$3 : x <= -1 ? -halfPi$3 : Math.asin(x);
    }

    function arcInnerRadius(d) {
        return d.innerRadius;
    }

    function arcOuterRadius(d) {
        return d.outerRadius;
    }

    function arcStartAngle(d) {
        return d.startAngle;
    }

    function arcEndAngle(d) {
        return d.endAngle;
    }

    function arcPadAngle(d) {
        return d && d.padAngle; // Note: optional!
    }

    function intersect(x0, y0, x1, y1, x2, y2, x3, y3) {
        var x10 = x1 - x0, y10 = y1 - y0,
            x32 = x3 - x2, y32 = y3 - y2,
            t = (x32 * (y0 - y2) - y32 * (x0 - x2)) / (y32 * x10 - x32 * y10);
        return [x0 + t * x10, y0 + t * y10];
    }

// Compute perpendicular offset line of length rc.
// http://mathworld.wolfram.com/Circle-LineIntersection.html
    function cornerTangents(x0, y0, x1, y1, r1, rc, cw) {
        var x01 = x0 - x1,
            y01 = y0 - y1,
            lo = (cw ? rc : -rc) / sqrt$2(x01 * x01 + y01 * y01),
            ox = lo * y01,
            oy = -lo * x01,
            x11 = x0 + ox,
            y11 = y0 + oy,
            x10 = x1 + ox,
            y10 = y1 + oy,
            x00 = (x11 + x10) / 2,
            y00 = (y11 + y10) / 2,
            dx = x10 - x11,
            dy = y10 - y11,
            d2 = dx * dx + dy * dy,
            r = r1 - rc,
            D = x11 * y10 - x10 * y11,
            d = (dy < 0 ? -1 : 1) * sqrt$2(max$2(0, r * r * d2 - D * D)),
            cx0 = (D * dy - dx * d) / d2,
            cy0 = (-D * dx - dy * d) / d2,
            cx1 = (D * dy + dx * d) / d2,
            cy1 = (-D * dx + dy * d) / d2,
            dx0 = cx0 - x00,
            dy0 = cy0 - y00,
            dx1 = cx1 - x00,
            dy1 = cy1 - y00;

        // Pick the closer of the two intersection points.
        // TODO Is there a faster way to determine which intersection to use?
        if (dx0 * dx0 + dy0 * dy0 > dx1 * dx1 + dy1 * dy1) cx0 = cx1, cy0 = cy1;

        return {
            cx: cx0,
            cy: cy0,
            x01: -ox,
            y01: -oy,
            x11: cx0 * (r1 / r - 1),
            y11: cy0 * (r1 / r - 1)
        };
    }

    function arc() {
        var innerRadius = arcInnerRadius,
            outerRadius = arcOuterRadius,
            cornerRadius = constant$10(0),
            padRadius = null,
            startAngle = arcStartAngle,
            endAngle = arcEndAngle,
            padAngle = arcPadAngle,
            context = null;

        function arc() {
            var buffer,
                r,
                r0 = +innerRadius.apply(this, arguments),
                r1 = +outerRadius.apply(this, arguments),
                a0 = startAngle.apply(this, arguments) - halfPi$3,
                a1 = endAngle.apply(this, arguments) - halfPi$3,
                da = abs$1(a1 - a0),
                cw = a1 > a0;

            if (!context) context = buffer = path();

            // Ensure that the outer radius is always larger than the inner radius.
            if (r1 < r0) r = r1, r1 = r0, r0 = r;

            // Is it a point?
            if (!(r1 > epsilon$3)) context.moveTo(0, 0);

            // Or is it a circle or annulus?
            else if (da > tau$4 - epsilon$3) {
                context.moveTo(r1 * cos$2(a0), r1 * sin$2(a0));
                context.arc(0, 0, r1, a0, a1, !cw);
                if (r0 > epsilon$3) {
                    context.moveTo(r0 * cos$2(a1), r0 * sin$2(a1));
                    context.arc(0, 0, r0, a1, a0, cw);
                }
            }

            // Or is it a circular or annular sector?
            else {
                var a01 = a0,
                    a11 = a1,
                    a00 = a0,
                    a10 = a1,
                    da0 = da,
                    da1 = da,
                    ap = padAngle.apply(this, arguments) / 2,
                    rp = (ap > epsilon$3) && (padRadius ? +padRadius.apply(this, arguments) : sqrt$2(r0 * r0 + r1 * r1)),
                    rc = min$1(abs$1(r1 - r0) / 2, +cornerRadius.apply(this, arguments)),
                    rc0 = rc,
                    rc1 = rc,
                    t0,
                    t1;

                // Apply padding? Note that since r1 ≥ r0, da1 ≥ da0.
                if (rp > epsilon$3) {
                    var p0 = asin$1(rp / r0 * sin$2(ap)),
                        p1 = asin$1(rp / r1 * sin$2(ap));
                    if ((da0 -= p0 * 2) > epsilon$3) p0 *= (cw ? 1 : -1), a00 += p0, a10 -= p0;
                    else da0 = 0, a00 = a10 = (a0 + a1) / 2;
                    if ((da1 -= p1 * 2) > epsilon$3) p1 *= (cw ? 1 : -1), a01 += p1, a11 -= p1;
                    else da1 = 0, a01 = a11 = (a0 + a1) / 2;
                }

                var x01 = r1 * cos$2(a01),
                    y01 = r1 * sin$2(a01),
                    x10 = r0 * cos$2(a10),
                    y10 = r0 * sin$2(a10);

                // Apply rounded corners?
                if (rc > epsilon$3) {
                    var x11 = r1 * cos$2(a11),
                        y11 = r1 * sin$2(a11),
                        x00 = r0 * cos$2(a00),
                        y00 = r0 * sin$2(a00);

                    // Restrict the corner radius according to the sector angle.
                    if (da < pi$4) {
                        var oc = da0 > epsilon$3 ? intersect(x01, y01, x00, y00, x11, y11, x10, y10) : [x10, y10],
                            ax = x01 - oc[0],
                            ay = y01 - oc[1],
                            bx = x11 - oc[0],
                            by = y11 - oc[1],
                            kc = 1 / sin$2(acos$1((ax * bx + ay * by) / (sqrt$2(ax * ax + ay * ay) * sqrt$2(bx * bx + by * by))) / 2),
                            lc = sqrt$2(oc[0] * oc[0] + oc[1] * oc[1]);
                        rc0 = min$1(rc, (r0 - lc) / (kc - 1));
                        rc1 = min$1(rc, (r1 - lc) / (kc + 1));
                    }
                }

                // Is the sector collapsed to a line?
                if (!(da1 > epsilon$3)) context.moveTo(x01, y01);

                // Does the sector’s outer ring have rounded corners?
                else if (rc1 > epsilon$3) {
                    t0 = cornerTangents(x00, y00, x01, y01, r1, rc1, cw);
                    t1 = cornerTangents(x11, y11, x10, y10, r1, rc1, cw);

                    context.moveTo(t0.cx + t0.x01, t0.cy + t0.y01);

                    // Have the corners merged?
                    if (rc1 < rc) context.arc(t0.cx, t0.cy, rc1, atan2$1(t0.y01, t0.x01), atan2$1(t1.y01, t1.x01), !cw);

                    // Otherwise, draw the two corners and the ring.
                    else {
                        context.arc(t0.cx, t0.cy, rc1, atan2$1(t0.y01, t0.x01), atan2$1(t0.y11, t0.x11), !cw);
                        context.arc(0, 0, r1, atan2$1(t0.cy + t0.y11, t0.cx + t0.x11), atan2$1(t1.cy + t1.y11, t1.cx + t1.x11), !cw);
                        context.arc(t1.cx, t1.cy, rc1, atan2$1(t1.y11, t1.x11), atan2$1(t1.y01, t1.x01), !cw);
                    }
                }

                // Or is the outer ring just a circular arc?
                else context.moveTo(x01, y01), context.arc(0, 0, r1, a01, a11, !cw);

                // Is there no inner ring, and it’s a circular sector?
                // Or perhaps it’s an annular sector collapsed due to padding?
                if (!(r0 > epsilon$3) || !(da0 > epsilon$3)) context.lineTo(x10, y10);

                // Does the sector’s inner ring (or point) have rounded corners?
                else if (rc0 > epsilon$3) {
                    t0 = cornerTangents(x10, y10, x11, y11, r0, -rc0, cw);
                    t1 = cornerTangents(x01, y01, x00, y00, r0, -rc0, cw);

                    context.lineTo(t0.cx + t0.x01, t0.cy + t0.y01);

                    // Have the corners merged?
                    if (rc0 < rc) context.arc(t0.cx, t0.cy, rc0, atan2$1(t0.y01, t0.x01), atan2$1(t1.y01, t1.x01), !cw);

                    // Otherwise, draw the two corners and the ring.
                    else {
                        context.arc(t0.cx, t0.cy, rc0, atan2$1(t0.y01, t0.x01), atan2$1(t0.y11, t0.x11), !cw);
                        context.arc(0, 0, r0, atan2$1(t0.cy + t0.y11, t0.cx + t0.x11), atan2$1(t1.cy + t1.y11, t1.cx + t1.x11), cw);
                        context.arc(t1.cx, t1.cy, rc0, atan2$1(t1.y11, t1.x11), atan2$1(t1.y01, t1.x01), !cw);
                    }
                }

                // Or is the inner ring just a circular arc?
                else context.arc(0, 0, r0, a10, a00, cw);
            }

            context.closePath();

            if (buffer) return context = null, buffer + "" || null;
        }

        arc.centroid = function() {
            var r = (+innerRadius.apply(this, arguments) + +outerRadius.apply(this, arguments)) / 2,
                a = (+startAngle.apply(this, arguments) + +endAngle.apply(this, arguments)) / 2 - pi$4 / 2;
            return [cos$2(a) * r, sin$2(a) * r];
        };

        arc.innerRadius = function(_) {
            return arguments.length ? (innerRadius = typeof _ === "function" ? _ : constant$10(+_), arc) : innerRadius;
        };

        arc.outerRadius = function(_) {
            return arguments.length ? (outerRadius = typeof _ === "function" ? _ : constant$10(+_), arc) : outerRadius;
        };

        arc.cornerRadius = function(_) {
            return arguments.length ? (cornerRadius = typeof _ === "function" ? _ : constant$10(+_), arc) : cornerRadius;
        };

        arc.padRadius = function(_) {
            return arguments.length ? (padRadius = _ == null ? null : typeof _ === "function" ? _ : constant$10(+_), arc) : padRadius;
        };

        arc.startAngle = function(_) {
            return arguments.length ? (startAngle = typeof _ === "function" ? _ : constant$10(+_), arc) : startAngle;
        };

        arc.endAngle = function(_) {
            return arguments.length ? (endAngle = typeof _ === "function" ? _ : constant$10(+_), arc) : endAngle;
        };

        arc.padAngle = function(_) {
            return arguments.length ? (padAngle = typeof _ === "function" ? _ : constant$10(+_), arc) : padAngle;
        };

        arc.context = function(_) {
            return arguments.length ? (context = _ == null ? null : _, arc) : context;
        };

        return arc;
    }

    function Linear(context) {
        this._context = context;
    }

    Linear.prototype = {
        areaStart: function() {
            this._line = 0;
        },
        areaEnd: function() {
            this._line = NaN;
        },
        lineStart: function() {
            this._point = 0;
        },
        lineEnd: function() {
            if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
            this._line = 1 - this._line;
        },
        point: function(x, y) {
            x = +x, y = +y;
            switch (this._point) {
                case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
                case 1: this._point = 2; // proceed
                default: this._context.lineTo(x, y); break;
            }
        }
    };

    function curveLinear(context) {
        return new Linear(context);
    }

    function x$3(p) {
        return p[0];
    }

    function y$3(p) {
        return p[1];
    }

    function line() {
        var x$$1 = x$3,
            y$$1 = y$3,
            defined = constant$10(true),
            context = null,
            curve = curveLinear,
            output = null;

        function line(data) {
            var i,
                n = data.length,
                d,
                defined0 = false,
                buffer;

            if (context == null) output = curve(buffer = path());

            for (i = 0; i <= n; ++i) {
                if (!(i < n && defined(d = data[i], i, data)) === defined0) {
                    if (defined0 = !defined0) output.lineStart();
                    else output.lineEnd();
                }
                if (defined0) output.point(+x$$1(d, i, data), +y$$1(d, i, data));
            }

            if (buffer) return output = null, buffer + "" || null;
        }

        line.x = function(_) {
            return arguments.length ? (x$$1 = typeof _ === "function" ? _ : constant$10(+_), line) : x$$1;
        };

        line.y = function(_) {
            return arguments.length ? (y$$1 = typeof _ === "function" ? _ : constant$10(+_), line) : y$$1;
        };

        line.defined = function(_) {
            return arguments.length ? (defined = typeof _ === "function" ? _ : constant$10(!!_), line) : defined;
        };

        line.curve = function(_) {
            return arguments.length ? (curve = _, context != null && (output = curve(context)), line) : curve;
        };

        line.context = function(_) {
            return arguments.length ? (_ == null ? context = output = null : output = curve(context = _), line) : context;
        };

        return line;
    }

    function area$2() {
        var x0 = x$3,
            x1 = null,
            y0 = constant$10(0),
            y1 = y$3,
            defined = constant$10(true),
            context = null,
            curve = curveLinear,
            output = null;

        function area(data) {
            var i,
                j,
                k,
                n = data.length,
                d,
                defined0 = false,
                buffer,
                x0z = new Array(n),
                y0z = new Array(n);

            if (context == null) output = curve(buffer = path());

            for (i = 0; i <= n; ++i) {
                if (!(i < n && defined(d = data[i], i, data)) === defined0) {
                    if (defined0 = !defined0) {
                        j = i;
                        output.areaStart();
                        output.lineStart();
                    } else {
                        output.lineEnd();
                        output.lineStart();
                        for (k = i - 1; k >= j; --k) {
                            output.point(x0z[k], y0z[k]);
                        }
                        output.lineEnd();
                        output.areaEnd();
                    }
                }
                if (defined0) {
                    x0z[i] = +x0(d, i, data), y0z[i] = +y0(d, i, data);
                    output.point(x1 ? +x1(d, i, data) : x0z[i], y1 ? +y1(d, i, data) : y0z[i]);
                }
            }

            if (buffer) return output = null, buffer + "" || null;
        }

        function arealine() {
            return line().defined(defined).curve(curve).context(context);
        }

        area.x = function(_) {
            return arguments.length ? (x0 = typeof _ === "function" ? _ : constant$10(+_), x1 = null, area) : x0;
        };

        area.x0 = function(_) {
            return arguments.length ? (x0 = typeof _ === "function" ? _ : constant$10(+_), area) : x0;
        };

        area.x1 = function(_) {
            return arguments.length ? (x1 = _ == null ? null : typeof _ === "function" ? _ : constant$10(+_), area) : x1;
        };

        area.y = function(_) {
            return arguments.length ? (y0 = typeof _ === "function" ? _ : constant$10(+_), y1 = null, area) : y0;
        };

        area.y0 = function(_) {
            return arguments.length ? (y0 = typeof _ === "function" ? _ : constant$10(+_), area) : y0;
        };

        area.y1 = function(_) {
            return arguments.length ? (y1 = _ == null ? null : typeof _ === "function" ? _ : constant$10(+_), area) : y1;
        };

        area.lineX0 =
            area.lineY0 = function() {
                return arealine().x(x0).y(y0);
            };

        area.lineY1 = function() {
            return arealine().x(x0).y(y1);
        };

        area.lineX1 = function() {
            return arealine().x(x1).y(y0);
        };

        area.defined = function(_) {
            return arguments.length ? (defined = typeof _ === "function" ? _ : constant$10(!!_), area) : defined;
        };

        area.curve = function(_) {
            return arguments.length ? (curve = _, context != null && (output = curve(context)), area) : curve;
        };

        area.context = function(_) {
            return arguments.length ? (_ == null ? context = output = null : output = curve(context = _), area) : context;
        };

        return area;
    }

    function descending$1(a, b) {
        return b < a ? -1 : b > a ? 1 : b >= a ? 0 : NaN;
    }

    function identity$7(d) {
        return d;
    }

    function pie() {
        var value = identity$7,
            sortValues = descending$1,
            sort = null,
            startAngle = constant$10(0),
            endAngle = constant$10(tau$4),
            padAngle = constant$10(0);

        function pie(data) {
            var i,
                n = data.length,
                j,
                k,
                sum = 0,
                index = new Array(n),
                arcs = new Array(n),
                a0 = +startAngle.apply(this, arguments),
                da = Math.min(tau$4, Math.max(-tau$4, endAngle.apply(this, arguments) - a0)),
                a1,
                p = Math.min(Math.abs(da) / n, padAngle.apply(this, arguments)),
                pa = p * (da < 0 ? -1 : 1),
                v;

            for (i = 0; i < n; ++i) {
                if ((v = arcs[index[i] = i] = +value(data[i], i, data)) > 0) {
                    sum += v;
                }
            }

            // Optionally sort the arcs by previously-computed values or by data.
            if (sortValues != null) index.sort(function(i, j) { return sortValues(arcs[i], arcs[j]); });
            else if (sort != null) index.sort(function(i, j) { return sort(data[i], data[j]); });

            // Compute the arcs! They are stored in the original data's order.
            for (i = 0, k = sum ? (da - n * pa) / sum : 0; i < n; ++i, a0 = a1) {
                j = index[i], v = arcs[j], a1 = a0 + (v > 0 ? v * k : 0) + pa, arcs[j] = {
                    data: data[j],
                    index: i,
                    value: v,
                    startAngle: a0,
                    endAngle: a1,
                    padAngle: p
                };
            }

            return arcs;
        }

        pie.value = function(_) {
            return arguments.length ? (value = typeof _ === "function" ? _ : constant$10(+_), pie) : value;
        };

        pie.sortValues = function(_) {
            return arguments.length ? (sortValues = _, sort = null, pie) : sortValues;
        };

        pie.sort = function(_) {
            return arguments.length ? (sort = _, sortValues = null, pie) : sort;
        };

        pie.startAngle = function(_) {
            return arguments.length ? (startAngle = typeof _ === "function" ? _ : constant$10(+_), pie) : startAngle;
        };

        pie.endAngle = function(_) {
            return arguments.length ? (endAngle = typeof _ === "function" ? _ : constant$10(+_), pie) : endAngle;
        };

        pie.padAngle = function(_) {
            return arguments.length ? (padAngle = typeof _ === "function" ? _ : constant$10(+_), pie) : padAngle;
        };

        return pie;
    }

    var curveRadialLinear = curveRadial(curveLinear);

    function Radial(curve) {
        this._curve = curve;
    }

    Radial.prototype = {
        areaStart: function() {
            this._curve.areaStart();
        },
        areaEnd: function() {
            this._curve.areaEnd();
        },
        lineStart: function() {
            this._curve.lineStart();
        },
        lineEnd: function() {
            this._curve.lineEnd();
        },
        point: function(a, r) {
            this._curve.point(r * Math.sin(a), r * -Math.cos(a));
        }
    };

    function curveRadial(curve) {

        function radial(context) {
            return new Radial(curve(context));
        }

        radial._curve = curve;

        return radial;
    }

    function lineRadial(l) {
        var c = l.curve;

        l.angle = l.x, delete l.x;
        l.radius = l.y, delete l.y;

        l.curve = function(_) {
            return arguments.length ? c(curveRadial(_)) : c()._curve;
        };

        return l;
    }

    function lineRadial$1() {
        return lineRadial(line().curve(curveRadialLinear));
    }

    function areaRadial() {
        var a = area$2().curve(curveRadialLinear),
            c = a.curve,
            x0 = a.lineX0,
            x1 = a.lineX1,
            y0 = a.lineY0,
            y1 = a.lineY1;

        a.angle = a.x, delete a.x;
        a.startAngle = a.x0, delete a.x0;
        a.endAngle = a.x1, delete a.x1;
        a.radius = a.y, delete a.y;
        a.innerRadius = a.y0, delete a.y0;
        a.outerRadius = a.y1, delete a.y1;
        a.lineStartAngle = function() { return lineRadial(x0()); }, delete a.lineX0;
        a.lineEndAngle = function() { return lineRadial(x1()); }, delete a.lineX1;
        a.lineInnerRadius = function() { return lineRadial(y0()); }, delete a.lineY0;
        a.lineOuterRadius = function() { return lineRadial(y1()); }, delete a.lineY1;

        a.curve = function(_) {
            return arguments.length ? c(curveRadial(_)) : c()._curve;
        };

        return a;
    }

    function pointRadial(x, y) {
        return [(y = +y) * Math.cos(x -= Math.PI / 2), y * Math.sin(x)];
    }

    var slice$6 = Array.prototype.slice;

    function linkSource(d) {
        return d.source;
    }

    function linkTarget(d) {
        return d.target;
    }

    function link$2(curve) {
        var source = linkSource,
            target = linkTarget,
            x$$1 = x$3,
            y$$1 = y$3,
            context = null;

        function link() {
            var buffer, argv = slice$6.call(arguments), s = source.apply(this, argv), t = target.apply(this, argv);
            if (!context) context = buffer = path();
            curve(context, +x$$1.apply(this, (argv[0] = s, argv)), +y$$1.apply(this, argv), +x$$1.apply(this, (argv[0] = t, argv)), +y$$1.apply(this, argv));
            if (buffer) return context = null, buffer + "" || null;
        }

        link.source = function(_) {
            return arguments.length ? (source = _, link) : source;
        };

        link.target = function(_) {
            return arguments.length ? (target = _, link) : target;
        };

        link.x = function(_) {
            return arguments.length ? (x$$1 = typeof _ === "function" ? _ : constant$10(+_), link) : x$$1;
        };

        link.y = function(_) {
            return arguments.length ? (y$$1 = typeof _ === "function" ? _ : constant$10(+_), link) : y$$1;
        };

        link.context = function(_) {
            return arguments.length ? (context = _ == null ? null : _, link) : context;
        };

        return link;
    }

    function curveHorizontal(context, x0, y0, x1, y1) {
        context.moveTo(x0, y0);
        context.bezierCurveTo(x0 = (x0 + x1) / 2, y0, x0, y1, x1, y1);
    }

    function curveVertical(context, x0, y0, x1, y1) {
        context.moveTo(x0, y0);
        context.bezierCurveTo(x0, y0 = (y0 + y1) / 2, x1, y0, x1, y1);
    }

    function curveRadial$1(context, x0, y0, x1, y1) {
        var p0 = pointRadial(x0, y0),
            p1 = pointRadial(x0, y0 = (y0 + y1) / 2),
            p2 = pointRadial(x1, y0),
            p3 = pointRadial(x1, y1);
        context.moveTo(p0[0], p0[1]);
        context.bezierCurveTo(p1[0], p1[1], p2[0], p2[1], p3[0], p3[1]);
    }

    function linkHorizontal() {
        return link$2(curveHorizontal);
    }

    function linkVertical() {
        return link$2(curveVertical);
    }

    function linkRadial() {
        var l = link$2(curveRadial$1);
        l.angle = l.x, delete l.x;
        l.radius = l.y, delete l.y;
        return l;
    }

    var circle$2 = {
        draw: function(context, size) {
            var r = Math.sqrt(size / pi$4);
            context.moveTo(r, 0);
            context.arc(0, 0, r, 0, tau$4);
        }
    };

    var cross$2 = {
        draw: function(context, size) {
            var r = Math.sqrt(size / 5) / 2;
            context.moveTo(-3 * r, -r);
            context.lineTo(-r, -r);
            context.lineTo(-r, -3 * r);
            context.lineTo(r, -3 * r);
            context.lineTo(r, -r);
            context.lineTo(3 * r, -r);
            context.lineTo(3 * r, r);
            context.lineTo(r, r);
            context.lineTo(r, 3 * r);
            context.lineTo(-r, 3 * r);
            context.lineTo(-r, r);
            context.lineTo(-3 * r, r);
            context.closePath();
        }
    };

    var tan30 = Math.sqrt(1 / 3);
    var tan30_2 = tan30 * 2;

    var diamond = {
        draw: function(context, size) {
            var y = Math.sqrt(size / tan30_2),
                x = y * tan30;
            context.moveTo(0, -y);
            context.lineTo(x, 0);
            context.lineTo(0, y);
            context.lineTo(-x, 0);
            context.closePath();
        }
    };

    var ka = 0.89081309152928522810;
    var kr = Math.sin(pi$4 / 10) / Math.sin(7 * pi$4 / 10);
    var kx = Math.sin(tau$4 / 10) * kr;
    var ky = -Math.cos(tau$4 / 10) * kr;

    var star = {
        draw: function(context, size) {
            var r = Math.sqrt(size * ka),
                x = kx * r,
                y = ky * r;
            context.moveTo(0, -r);
            context.lineTo(x, y);
            for (var i = 1; i < 5; ++i) {
                var a = tau$4 * i / 5,
                    c = Math.cos(a),
                    s = Math.sin(a);
                context.lineTo(s * r, -c * r);
                context.lineTo(c * x - s * y, s * x + c * y);
            }
            context.closePath();
        }
    };

    var square = {
        draw: function(context, size) {
            var w = Math.sqrt(size),
                x = -w / 2;
            context.rect(x, x, w, w);
        }
    };

    var sqrt3 = Math.sqrt(3);

    var triangle = {
        draw: function(context, size) {
            var y = -Math.sqrt(size / (sqrt3 * 3));
            context.moveTo(0, y * 2);
            context.lineTo(-sqrt3 * y, -y);
            context.lineTo(sqrt3 * y, -y);
            context.closePath();
        }
    };

    var c = -0.5;
    var s = Math.sqrt(3) / 2;
    var k = 1 / Math.sqrt(12);
    var a = (k / 2 + 1) * 3;

    var wye = {
        draw: function(context, size) {
            var r = Math.sqrt(size / a),
                x0 = r / 2,
                y0 = r * k,
                x1 = x0,
                y1 = r * k + r,
                x2 = -x1,
                y2 = y1;
            context.moveTo(x0, y0);
            context.lineTo(x1, y1);
            context.lineTo(x2, y2);
            context.lineTo(c * x0 - s * y0, s * x0 + c * y0);
            context.lineTo(c * x1 - s * y1, s * x1 + c * y1);
            context.lineTo(c * x2 - s * y2, s * x2 + c * y2);
            context.lineTo(c * x0 + s * y0, c * y0 - s * x0);
            context.lineTo(c * x1 + s * y1, c * y1 - s * x1);
            context.lineTo(c * x2 + s * y2, c * y2 - s * x2);
            context.closePath();
        }
    };

    var symbols = [
        circle$2,
        cross$2,
        diamond,
        square,
        star,
        triangle,
        wye
    ];

    function symbol() {
        var type = constant$10(circle$2),
            size = constant$10(64),
            context = null;

        function symbol() {
            var buffer;
            if (!context) context = buffer = path();
            type.apply(this, arguments).draw(context, +size.apply(this, arguments));
            if (buffer) return context = null, buffer + "" || null;
        }

        symbol.type = function(_) {
            return arguments.length ? (type = typeof _ === "function" ? _ : constant$10(_), symbol) : type;
        };

        symbol.size = function(_) {
            return arguments.length ? (size = typeof _ === "function" ? _ : constant$10(+_), symbol) : size;
        };

        symbol.context = function(_) {
            return arguments.length ? (context = _ == null ? null : _, symbol) : context;
        };

        return symbol;
    }

    function noop$2() {}

    function point$2(that, x, y) {
        that._context.bezierCurveTo(
            (2 * that._x0 + that._x1) / 3,
            (2 * that._y0 + that._y1) / 3,
            (that._x0 + 2 * that._x1) / 3,
            (that._y0 + 2 * that._y1) / 3,
            (that._x0 + 4 * that._x1 + x) / 6,
            (that._y0 + 4 * that._y1 + y) / 6
        );
    }

    function Basis(context) {
        this._context = context;
    }

    Basis.prototype = {
        areaStart: function() {
            this._line = 0;
        },
        areaEnd: function() {
            this._line = NaN;
        },
        lineStart: function() {
            this._x0 = this._x1 =
                this._y0 = this._y1 = NaN;
            this._point = 0;
        },
        lineEnd: function() {
            switch (this._point) {
                case 3: point$2(this, this._x1, this._y1); // proceed
                case 2: this._context.lineTo(this._x1, this._y1); break;
            }
            if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
            this._line = 1 - this._line;
        },
        point: function(x, y) {
            x = +x, y = +y;
            switch (this._point) {
                case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
                case 1: this._point = 2; break;
                case 2: this._point = 3; this._context.lineTo((5 * this._x0 + this._x1) / 6, (5 * this._y0 + this._y1) / 6); // proceed
                default: point$2(this, x, y); break;
            }
            this._x0 = this._x1, this._x1 = x;
            this._y0 = this._y1, this._y1 = y;
        }
    };

    function basis$2(context) {
        return new Basis(context);
    }

    function BasisClosed(context) {
        this._context = context;
    }

    BasisClosed.prototype = {
        areaStart: noop$2,
        areaEnd: noop$2,
        lineStart: function() {
            this._x0 = this._x1 = this._x2 = this._x3 = this._x4 =
                this._y0 = this._y1 = this._y2 = this._y3 = this._y4 = NaN;
            this._point = 0;
        },
        lineEnd: function() {
            switch (this._point) {
                case 1: {
                    this._context.moveTo(this._x2, this._y2);
                    this._context.closePath();
                    break;
                }
                case 2: {
                    this._context.moveTo((this._x2 + 2 * this._x3) / 3, (this._y2 + 2 * this._y3) / 3);
                    this._context.lineTo((this._x3 + 2 * this._x2) / 3, (this._y3 + 2 * this._y2) / 3);
                    this._context.closePath();
                    break;
                }
                case 3: {
                    this.point(this._x2, this._y2);
                    this.point(this._x3, this._y3);
                    this.point(this._x4, this._y4);
                    break;
                }
            }
        },
        point: function(x, y) {
            x = +x, y = +y;
            switch (this._point) {
                case 0: this._point = 1; this._x2 = x, this._y2 = y; break;
                case 1: this._point = 2; this._x3 = x, this._y3 = y; break;
                case 2: this._point = 3; this._x4 = x, this._y4 = y; this._context.moveTo((this._x0 + 4 * this._x1 + x) / 6, (this._y0 + 4 * this._y1 + y) / 6); break;
                default: point$2(this, x, y); break;
            }
            this._x0 = this._x1, this._x1 = x;
            this._y0 = this._y1, this._y1 = y;
        }
    };

    function basisClosed$1(context) {
        return new BasisClosed(context);
    }

    function BasisOpen(context) {
        this._context = context;
    }

    BasisOpen.prototype = {
        areaStart: function() {
            this._line = 0;
        },
        areaEnd: function() {
            this._line = NaN;
        },
        lineStart: function() {
            this._x0 = this._x1 =
                this._y0 = this._y1 = NaN;
            this._point = 0;
        },
        lineEnd: function() {
            if (this._line || (this._line !== 0 && this._point === 3)) this._context.closePath();
            this._line = 1 - this._line;
        },
        point: function(x, y) {
            x = +x, y = +y;
            switch (this._point) {
                case 0: this._point = 1; break;
                case 1: this._point = 2; break;
                case 2: this._point = 3; var x0 = (this._x0 + 4 * this._x1 + x) / 6, y0 = (this._y0 + 4 * this._y1 + y) / 6; this._line ? this._context.lineTo(x0, y0) : this._context.moveTo(x0, y0); break;
                case 3: this._point = 4; // proceed
                default: point$2(this, x, y); break;
            }
            this._x0 = this._x1, this._x1 = x;
            this._y0 = this._y1, this._y1 = y;
        }
    };

    function basisOpen(context) {
        return new BasisOpen(context);
    }

    function Bundle(context, beta) {
        this._basis = new Basis(context);
        this._beta = beta;
    }

    Bundle.prototype = {
        lineStart: function() {
            this._x = [];
            this._y = [];
            this._basis.lineStart();
        },
        lineEnd: function() {
            var x = this._x,
                y = this._y,
                j = x.length - 1;

            if (j > 0) {
                var x0 = x[0],
                    y0 = y[0],
                    dx = x[j] - x0,
                    dy = y[j] - y0,
                    i = -1,
                    t;

                while (++i <= j) {
                    t = i / j;
                    this._basis.point(
                        this._beta * x[i] + (1 - this._beta) * (x0 + t * dx),
                        this._beta * y[i] + (1 - this._beta) * (y0 + t * dy)
                    );
                }
            }

            this._x = this._y = null;
            this._basis.lineEnd();
        },
        point: function(x, y) {
            this._x.push(+x);
            this._y.push(+y);
        }
    };

    var bundle = (function custom(beta) {

        function bundle(context) {
            return beta === 1 ? new Basis(context) : new Bundle(context, beta);
        }

        bundle.beta = function(beta) {
            return custom(+beta);
        };

        return bundle;
    })(0.85);

    function point$3(that, x, y) {
        that._context.bezierCurveTo(
            that._x1 + that._k * (that._x2 - that._x0),
            that._y1 + that._k * (that._y2 - that._y0),
            that._x2 + that._k * (that._x1 - x),
            that._y2 + that._k * (that._y1 - y),
            that._x2,
            that._y2
        );
    }

    function Cardinal(context, tension) {
        this._context = context;
        this._k = (1 - tension) / 6;
    }

    Cardinal.prototype = {
        areaStart: function() {
            this._line = 0;
        },
        areaEnd: function() {
            this._line = NaN;
        },
        lineStart: function() {
            this._x0 = this._x1 = this._x2 =
                this._y0 = this._y1 = this._y2 = NaN;
            this._point = 0;
        },
        lineEnd: function() {
            switch (this._point) {
                case 2: this._context.lineTo(this._x2, this._y2); break;
                case 3: point$3(this, this._x1, this._y1); break;
            }
            if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
            this._line = 1 - this._line;
        },
        point: function(x, y) {
            x = +x, y = +y;
            switch (this._point) {
                case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
                case 1: this._point = 2; this._x1 = x, this._y1 = y; break;
                case 2: this._point = 3; // proceed
                default: point$3(this, x, y); break;
            }
            this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
            this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
        }
    };

    var cardinal = (function custom(tension) {

        function cardinal(context) {
            return new Cardinal(context, tension);
        }

        cardinal.tension = function(tension) {
            return custom(+tension);
        };

        return cardinal;
    })(0);

    function CardinalClosed(context, tension) {
        this._context = context;
        this._k = (1 - tension) / 6;
    }

    CardinalClosed.prototype = {
        areaStart: noop$2,
        areaEnd: noop$2,
        lineStart: function() {
            this._x0 = this._x1 = this._x2 = this._x3 = this._x4 = this._x5 =
                this._y0 = this._y1 = this._y2 = this._y3 = this._y4 = this._y5 = NaN;
            this._point = 0;
        },
        lineEnd: function() {
            switch (this._point) {
                case 1: {
                    this._context.moveTo(this._x3, this._y3);
                    this._context.closePath();
                    break;
                }
                case 2: {
                    this._context.lineTo(this._x3, this._y3);
                    this._context.closePath();
                    break;
                }
                case 3: {
                    this.point(this._x3, this._y3);
                    this.point(this._x4, this._y4);
                    this.point(this._x5, this._y5);
                    break;
                }
            }
        },
        point: function(x, y) {
            x = +x, y = +y;
            switch (this._point) {
                case 0: this._point = 1; this._x3 = x, this._y3 = y; break;
                case 1: this._point = 2; this._context.moveTo(this._x4 = x, this._y4 = y); break;
                case 2: this._point = 3; this._x5 = x, this._y5 = y; break;
                default: point$3(this, x, y); break;
            }
            this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
            this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
        }
    };

    var cardinalClosed = (function custom(tension) {

        function cardinal$$1(context) {
            return new CardinalClosed(context, tension);
        }

        cardinal$$1.tension = function(tension) {
            return custom(+tension);
        };

        return cardinal$$1;
    })(0);

    function CardinalOpen(context, tension) {
        this._context = context;
        this._k = (1 - tension) / 6;
    }

    CardinalOpen.prototype = {
        areaStart: function() {
            this._line = 0;
        },
        areaEnd: function() {
            this._line = NaN;
        },
        lineStart: function() {
            this._x0 = this._x1 = this._x2 =
                this._y0 = this._y1 = this._y2 = NaN;
            this._point = 0;
        },
        lineEnd: function() {
            if (this._line || (this._line !== 0 && this._point === 3)) this._context.closePath();
            this._line = 1 - this._line;
        },
        point: function(x, y) {
            x = +x, y = +y;
            switch (this._point) {
                case 0: this._point = 1; break;
                case 1: this._point = 2; break;
                case 2: this._point = 3; this._line ? this._context.lineTo(this._x2, this._y2) : this._context.moveTo(this._x2, this._y2); break;
                case 3: this._point = 4; // proceed
                default: point$3(this, x, y); break;
            }
            this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
            this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
        }
    };

    var cardinalOpen = (function custom(tension) {

        function cardinal$$1(context) {
            return new CardinalOpen(context, tension);
        }

        cardinal$$1.tension = function(tension) {
            return custom(+tension);
        };

        return cardinal$$1;
    })(0);

    function point$4(that, x, y) {
        var x1 = that._x1,
            y1 = that._y1,
            x2 = that._x2,
            y2 = that._y2;

        if (that._l01_a > epsilon$3) {
            var a = 2 * that._l01_2a + 3 * that._l01_a * that._l12_a + that._l12_2a,
                n = 3 * that._l01_a * (that._l01_a + that._l12_a);
            x1 = (x1 * a - that._x0 * that._l12_2a + that._x2 * that._l01_2a) / n;
            y1 = (y1 * a - that._y0 * that._l12_2a + that._y2 * that._l01_2a) / n;
        }

        if (that._l23_a > epsilon$3) {
            var b = 2 * that._l23_2a + 3 * that._l23_a * that._l12_a + that._l12_2a,
                m = 3 * that._l23_a * (that._l23_a + that._l12_a);
            x2 = (x2 * b + that._x1 * that._l23_2a - x * that._l12_2a) / m;
            y2 = (y2 * b + that._y1 * that._l23_2a - y * that._l12_2a) / m;
        }

        that._context.bezierCurveTo(x1, y1, x2, y2, that._x2, that._y2);
    }

    function CatmullRom(context, alpha) {
        this._context = context;
        this._alpha = alpha;
    }

    CatmullRom.prototype = {
        areaStart: function() {
            this._line = 0;
        },
        areaEnd: function() {
            this._line = NaN;
        },
        lineStart: function() {
            this._x0 = this._x1 = this._x2 =
                this._y0 = this._y1 = this._y2 = NaN;
            this._l01_a = this._l12_a = this._l23_a =
                this._l01_2a = this._l12_2a = this._l23_2a =
                    this._point = 0;
        },
        lineEnd: function() {
            switch (this._point) {
                case 2: this._context.lineTo(this._x2, this._y2); break;
                case 3: this.point(this._x2, this._y2); break;
            }
            if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
            this._line = 1 - this._line;
        },
        point: function(x, y) {
            x = +x, y = +y;

            if (this._point) {
                var x23 = this._x2 - x,
                    y23 = this._y2 - y;
                this._l23_a = Math.sqrt(this._l23_2a = Math.pow(x23 * x23 + y23 * y23, this._alpha));
            }

            switch (this._point) {
                case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
                case 1: this._point = 2; break;
                case 2: this._point = 3; // proceed
                default: point$4(this, x, y); break;
            }

            this._l01_a = this._l12_a, this._l12_a = this._l23_a;
            this._l01_2a = this._l12_2a, this._l12_2a = this._l23_2a;
            this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
            this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
        }
    };

    var catmullRom = (function custom(alpha) {

        function catmullRom(context) {
            return alpha ? new CatmullRom(context, alpha) : new Cardinal(context, 0);
        }

        catmullRom.alpha = function(alpha) {
            return custom(+alpha);
        };

        return catmullRom;
    })(0.5);

    function CatmullRomClosed(context, alpha) {
        this._context = context;
        this._alpha = alpha;
    }

    CatmullRomClosed.prototype = {
        areaStart: noop$2,
        areaEnd: noop$2,
        lineStart: function() {
            this._x0 = this._x1 = this._x2 = this._x3 = this._x4 = this._x5 =
                this._y0 = this._y1 = this._y2 = this._y3 = this._y4 = this._y5 = NaN;
            this._l01_a = this._l12_a = this._l23_a =
                this._l01_2a = this._l12_2a = this._l23_2a =
                    this._point = 0;
        },
        lineEnd: function() {
            switch (this._point) {
                case 1: {
                    this._context.moveTo(this._x3, this._y3);
                    this._context.closePath();
                    break;
                }
                case 2: {
                    this._context.lineTo(this._x3, this._y3);
                    this._context.closePath();
                    break;
                }
                case 3: {
                    this.point(this._x3, this._y3);
                    this.point(this._x4, this._y4);
                    this.point(this._x5, this._y5);
                    break;
                }
            }
        },
        point: function(x, y) {
            x = +x, y = +y;

            if (this._point) {
                var x23 = this._x2 - x,
                    y23 = this._y2 - y;
                this._l23_a = Math.sqrt(this._l23_2a = Math.pow(x23 * x23 + y23 * y23, this._alpha));
            }

            switch (this._point) {
                case 0: this._point = 1; this._x3 = x, this._y3 = y; break;
                case 1: this._point = 2; this._context.moveTo(this._x4 = x, this._y4 = y); break;
                case 2: this._point = 3; this._x5 = x, this._y5 = y; break;
                default: point$4(this, x, y); break;
            }

            this._l01_a = this._l12_a, this._l12_a = this._l23_a;
            this._l01_2a = this._l12_2a, this._l12_2a = this._l23_2a;
            this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
            this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
        }
    };

    var catmullRomClosed = (function custom(alpha) {

        function catmullRom$$1(context) {
            return alpha ? new CatmullRomClosed(context, alpha) : new CardinalClosed(context, 0);
        }

        catmullRom$$1.alpha = function(alpha) {
            return custom(+alpha);
        };

        return catmullRom$$1;
    })(0.5);

    function CatmullRomOpen(context, alpha) {
        this._context = context;
        this._alpha = alpha;
    }

    CatmullRomOpen.prototype = {
        areaStart: function() {
            this._line = 0;
        },
        areaEnd: function() {
            this._line = NaN;
        },
        lineStart: function() {
            this._x0 = this._x1 = this._x2 =
                this._y0 = this._y1 = this._y2 = NaN;
            this._l01_a = this._l12_a = this._l23_a =
                this._l01_2a = this._l12_2a = this._l23_2a =
                    this._point = 0;
        },
        lineEnd: function() {
            if (this._line || (this._line !== 0 && this._point === 3)) this._context.closePath();
            this._line = 1 - this._line;
        },
        point: function(x, y) {
            x = +x, y = +y;

            if (this._point) {
                var x23 = this._x2 - x,
                    y23 = this._y2 - y;
                this._l23_a = Math.sqrt(this._l23_2a = Math.pow(x23 * x23 + y23 * y23, this._alpha));
            }

            switch (this._point) {
                case 0: this._point = 1; break;
                case 1: this._point = 2; break;
                case 2: this._point = 3; this._line ? this._context.lineTo(this._x2, this._y2) : this._context.moveTo(this._x2, this._y2); break;
                case 3: this._point = 4; // proceed
                default: point$4(this, x, y); break;
            }

            this._l01_a = this._l12_a, this._l12_a = this._l23_a;
            this._l01_2a = this._l12_2a, this._l12_2a = this._l23_2a;
            this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
            this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
        }
    };

    var catmullRomOpen = (function custom(alpha) {

        function catmullRom$$1(context) {
            return alpha ? new CatmullRomOpen(context, alpha) : new CardinalOpen(context, 0);
        }

        catmullRom$$1.alpha = function(alpha) {
            return custom(+alpha);
        };

        return catmullRom$$1;
    })(0.5);

    function LinearClosed(context) {
        this._context = context;
    }

    LinearClosed.prototype = {
        areaStart: noop$2,
        areaEnd: noop$2,
        lineStart: function() {
            this._point = 0;
        },
        lineEnd: function() {
            if (this._point) this._context.closePath();
        },
        point: function(x, y) {
            x = +x, y = +y;
            if (this._point) this._context.lineTo(x, y);
            else this._point = 1, this._context.moveTo(x, y);
        }
    };

    function linearClosed(context) {
        return new LinearClosed(context);
    }

    function sign$1(x) {
        return x < 0 ? -1 : 1;
    }

// Calculate the slopes of the tangents (Hermite-type interpolation) based on
// the following paper: Steffen, M. 1990. A Simple Method for Monotonic
// Interpolation in One Dimension. Astronomy and Astrophysics, Vol. 239, NO.
// NOV(II), P. 443, 1990.
    function slope3(that, x2, y2) {
        var h0 = that._x1 - that._x0,
            h1 = x2 - that._x1,
            s0 = (that._y1 - that._y0) / (h0 || h1 < 0 && -0),
            s1 = (y2 - that._y1) / (h1 || h0 < 0 && -0),
            p = (s0 * h1 + s1 * h0) / (h0 + h1);
        return (sign$1(s0) + sign$1(s1)) * Math.min(Math.abs(s0), Math.abs(s1), 0.5 * Math.abs(p)) || 0;
    }

// Calculate a one-sided slope.
    function slope2(that, t) {
        var h = that._x1 - that._x0;
        return h ? (3 * (that._y1 - that._y0) / h - t) / 2 : t;
    }

// According to https://en.wikipedia.org/wiki/Cubic_Hermite_spline#Representations
// "you can express cubic Hermite interpolation in terms of cubic Bézier curves
// with respect to the four values p0, p0 + m0 / 3, p1 - m1 / 3, p1".
    function point$5(that, t0, t1) {
        var x0 = that._x0,
            y0 = that._y0,
            x1 = that._x1,
            y1 = that._y1,
            dx = (x1 - x0) / 3;
        that._context.bezierCurveTo(x0 + dx, y0 + dx * t0, x1 - dx, y1 - dx * t1, x1, y1);
    }

    function MonotoneX(context) {
        this._context = context;
    }

    MonotoneX.prototype = {
        areaStart: function() {
            this._line = 0;
        },
        areaEnd: function() {
            this._line = NaN;
        },
        lineStart: function() {
            this._x0 = this._x1 =
                this._y0 = this._y1 =
                    this._t0 = NaN;
            this._point = 0;
        },
        lineEnd: function() {
            switch (this._point) {
                case 2: this._context.lineTo(this._x1, this._y1); break;
                case 3: point$5(this, this._t0, slope2(this, this._t0)); break;
            }
            if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
            this._line = 1 - this._line;
        },
        point: function(x, y) {
            var t1 = NaN;

            x = +x, y = +y;
            if (x === this._x1 && y === this._y1) return; // Ignore coincident points.
            switch (this._point) {
                case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
                case 1: this._point = 2; break;
                case 2: this._point = 3; point$5(this, slope2(this, t1 = slope3(this, x, y)), t1); break;
                default: point$5(this, this._t0, t1 = slope3(this, x, y)); break;
            }

            this._x0 = this._x1, this._x1 = x;
            this._y0 = this._y1, this._y1 = y;
            this._t0 = t1;
        }
    };

    function MonotoneY(context) {
        this._context = new ReflectContext(context);
    }

    (MonotoneY.prototype = Object.create(MonotoneX.prototype)).point = function(x, y) {
        MonotoneX.prototype.point.call(this, y, x);
    };

    function ReflectContext(context) {
        this._context = context;
    }

    ReflectContext.prototype = {
        moveTo: function(x, y) { this._context.moveTo(y, x); },
        closePath: function() { this._context.closePath(); },
        lineTo: function(x, y) { this._context.lineTo(y, x); },
        bezierCurveTo: function(x1, y1, x2, y2, x, y) { this._context.bezierCurveTo(y1, x1, y2, x2, y, x); }
    };

    function monotoneX(context) {
        return new MonotoneX(context);
    }

    function monotoneY(context) {
        return new MonotoneY(context);
    }

    function Natural(context) {
        this._context = context;
    }

    Natural.prototype = {
        areaStart: function() {
            this._line = 0;
        },
        areaEnd: function() {
            this._line = NaN;
        },
        lineStart: function() {
            this._x = [];
            this._y = [];
        },
        lineEnd: function() {
            var x = this._x,
                y = this._y,
                n = x.length;

            if (n) {
                this._line ? this._context.lineTo(x[0], y[0]) : this._context.moveTo(x[0], y[0]);
                if (n === 2) {
                    this._context.lineTo(x[1], y[1]);
                } else {
                    var px = controlPoints(x),
                        py = controlPoints(y);
                    for (var i0 = 0, i1 = 1; i1 < n; ++i0, ++i1) {
                        this._context.bezierCurveTo(px[0][i0], py[0][i0], px[1][i0], py[1][i0], x[i1], y[i1]);
                    }
                }
            }

            if (this._line || (this._line !== 0 && n === 1)) this._context.closePath();
            this._line = 1 - this._line;
            this._x = this._y = null;
        },
        point: function(x, y) {
            this._x.push(+x);
            this._y.push(+y);
        }
    };

// See https://www.particleincell.com/2012/bezier-splines/ for derivation.
    function controlPoints(x) {
        var i,
            n = x.length - 1,
            m,
            a = new Array(n),
            b = new Array(n),
            r = new Array(n);
        a[0] = 0, b[0] = 2, r[0] = x[0] + 2 * x[1];
        for (i = 1; i < n - 1; ++i) a[i] = 1, b[i] = 4, r[i] = 4 * x[i] + 2 * x[i + 1];
        a[n - 1] = 2, b[n - 1] = 7, r[n - 1] = 8 * x[n - 1] + x[n];
        for (i = 1; i < n; ++i) m = a[i] / b[i - 1], b[i] -= m, r[i] -= m * r[i - 1];
        a[n - 1] = r[n - 1] / b[n - 1];
        for (i = n - 2; i >= 0; --i) a[i] = (r[i] - a[i + 1]) / b[i];
        b[n - 1] = (x[n] + a[n - 1]) / 2;
        for (i = 0; i < n - 1; ++i) b[i] = 2 * x[i + 1] - a[i + 1];
        return [a, b];
    }

    function natural(context) {
        return new Natural(context);
    }

    function Step(context, t) {
        this._context = context;
        this._t = t;
    }

    Step.prototype = {
        areaStart: function() {
            this._line = 0;
        },
        areaEnd: function() {
            this._line = NaN;
        },
        lineStart: function() {
            this._x = this._y = NaN;
            this._point = 0;
        },
        lineEnd: function() {
            if (0 < this._t && this._t < 1 && this._point === 2) this._context.lineTo(this._x, this._y);
            if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
            if (this._line >= 0) this._t = 1 - this._t, this._line = 1 - this._line;
        },
        point: function(x, y) {
            x = +x, y = +y;
            switch (this._point) {
                case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break;
                case 1: this._point = 2; // proceed
                default: {
                    if (this._t <= 0) {
                        this._context.lineTo(this._x, y);
                        this._context.lineTo(x, y);
                    } else {
                        var x1 = this._x * (1 - this._t) + x * this._t;
                        this._context.lineTo(x1, this._y);
                        this._context.lineTo(x1, y);
                    }
                    break;
                }
            }
            this._x = x, this._y = y;
        }
    };

    function step(context) {
        return new Step(context, 0.5);
    }

    function stepBefore(context) {
        return new Step(context, 0);
    }

    function stepAfter(context) {
        return new Step(context, 1);
    }

    function none$1(series, order) {
        if (!((n = series.length) > 1)) return;
        for (var i = 1, j, s0, s1 = series[order[0]], n, m = s1.length; i < n; ++i) {
            s0 = s1, s1 = series[order[i]];
            for (j = 0; j < m; ++j) {
                s1[j][1] += s1[j][0] = isNaN(s0[j][1]) ? s0[j][0] : s0[j][1];
            }
        }
    }

    function none$2(series) {
        var n = series.length, o = new Array(n);
        while (--n >= 0) o[n] = n;
        return o;
    }

    function stackValue(d, key) {
        return d[key];
    }

    function stack() {
        var keys = constant$10([]),
            order = none$2,
            offset = none$1,
            value = stackValue;

        function stack(data) {
            var kz = keys.apply(this, arguments),
                i,
                m = data.length,
                n = kz.length,
                sz = new Array(n),
                oz;

            for (i = 0; i < n; ++i) {
                for (var ki = kz[i], si = sz[i] = new Array(m), j = 0, sij; j < m; ++j) {
                    si[j] = sij = [0, +value(data[j], ki, j, data)];
                    sij.data = data[j];
                }
                si.key = ki;
            }

            for (i = 0, oz = order(sz); i < n; ++i) {
                sz[oz[i]].index = i;
            }

            offset(sz, oz);
            return sz;
        }

        stack.keys = function(_) {
            return arguments.length ? (keys = typeof _ === "function" ? _ : constant$10(slice$6.call(_)), stack) : keys;
        };

        stack.value = function(_) {
            return arguments.length ? (value = typeof _ === "function" ? _ : constant$10(+_), stack) : value;
        };

        stack.order = function(_) {
            return arguments.length ? (order = _ == null ? none$2 : typeof _ === "function" ? _ : constant$10(slice$6.call(_)), stack) : order;
        };

        stack.offset = function(_) {
            return arguments.length ? (offset = _ == null ? none$1 : _, stack) : offset;
        };

        return stack;
    }

    function expand(series, order) {
        if (!((n = series.length) > 0)) return;
        for (var i, n, j = 0, m = series[0].length, y; j < m; ++j) {
            for (y = i = 0; i < n; ++i) y += series[i][j][1] || 0;
            if (y) for (i = 0; i < n; ++i) series[i][j][1] /= y;
        }
        none$1(series, order);
    }

    function diverging(series, order) {
        if (!((n = series.length) > 1)) return;
        for (var i, j = 0, d, dy, yp, yn, n, m = series[order[0]].length; j < m; ++j) {
            for (yp = yn = 0, i = 0; i < n; ++i) {
                if ((dy = (d = series[order[i]][j])[1] - d[0]) >= 0) {
                    d[0] = yp, d[1] = yp += dy;
                } else if (dy < 0) {
                    d[1] = yn, d[0] = yn += dy;
                } else {
                    d[0] = yp;
                }
            }
        }
    }

    function silhouette(series, order) {
        if (!((n = series.length) > 0)) return;
        for (var j = 0, s0 = series[order[0]], n, m = s0.length; j < m; ++j) {
            for (var i = 0, y = 0; i < n; ++i) y += series[i][j][1] || 0;
            s0[j][1] += s0[j][0] = -y / 2;
        }
        none$1(series, order);
    }

    function wiggle(series, order) {
        if (!((n = series.length) > 0) || !((m = (s0 = series[order[0]]).length) > 0)) return;
        for (var y = 0, j = 1, s0, m, n; j < m; ++j) {
            for (var i = 0, s1 = 0, s2 = 0; i < n; ++i) {
                var si = series[order[i]],
                    sij0 = si[j][1] || 0,
                    sij1 = si[j - 1][1] || 0,
                    s3 = (sij0 - sij1) / 2;
                for (var k = 0; k < i; ++k) {
                    var sk = series[order[k]],
                        skj0 = sk[j][1] || 0,
                        skj1 = sk[j - 1][1] || 0;
                    s3 += skj0 - skj1;
                }
                s1 += sij0, s2 += s3 * sij0;
            }
            s0[j - 1][1] += s0[j - 1][0] = y;
            if (s1) y -= s2 / s1;
        }
        s0[j - 1][1] += s0[j - 1][0] = y;
        none$1(series, order);
    }

    function ascending$2(series) {
        var sums = series.map(sum$2);
        return none$2(series).sort(function(a, b) { return sums[a] - sums[b]; });
    }

    function sum$2(series) {
        var s = 0, i = -1, n = series.length, v;
        while (++i < n) if (v = +series[i][1]) s += v;
        return s;
    }

    function descending$2(series) {
        return ascending$2(series).reverse();
    }

    function insideOut(series) {
        var n = series.length,
            i,
            j,
            sums = series.map(sum$2),
            order = none$2(series).sort(function(a, b) { return sums[b] - sums[a]; }),
            top = 0,
            bottom = 0,
            tops = [],
            bottoms = [];

        for (i = 0; i < n; ++i) {
            j = order[i];
            if (top < bottom) {
                top += sums[j];
                tops.push(j);
            } else {
                bottom += sums[j];
                bottoms.push(j);
            }
        }

        return bottoms.reverse().concat(tops);
    }

    function reverse(series) {
        return none$2(series).reverse();
    }

    function constant$11(x) {
        return function() {
            return x;
        };
    }

    function x$4(d) {
        return d[0];
    }

    function y$4(d) {
        return d[1];
    }

    function RedBlackTree() {
        this._ = null; // root node
    }

    function RedBlackNode(node) {
        node.U = // parent node
            node.C = // color - true for red, false for black
                node.L = // left node
                    node.R = // right node
                        node.P = // previous node
                            node.N = null; // next node
    }

    RedBlackTree.prototype = {
        constructor: RedBlackTree,

        insert: function(after, node) {
            var parent, grandpa, uncle;

            if (after) {
                node.P = after;
                node.N = after.N;
                if (after.N) after.N.P = node;
                after.N = node;
                if (after.R) {
                    after = after.R;
                    while (after.L) after = after.L;
                    after.L = node;
                } else {
                    after.R = node;
                }
                parent = after;
            } else if (this._) {
                after = RedBlackFirst(this._);
                node.P = null;
                node.N = after;
                after.P = after.L = node;
                parent = after;
            } else {
                node.P = node.N = null;
                this._ = node;
                parent = null;
            }
            node.L = node.R = null;
            node.U = parent;
            node.C = true;

            after = node;
            while (parent && parent.C) {
                grandpa = parent.U;
                if (parent === grandpa.L) {
                    uncle = grandpa.R;
                    if (uncle && uncle.C) {
                        parent.C = uncle.C = false;
                        grandpa.C = true;
                        after = grandpa;
                    } else {
                        if (after === parent.R) {
                            RedBlackRotateLeft(this, parent);
                            after = parent;
                            parent = after.U;
                        }
                        parent.C = false;
                        grandpa.C = true;
                        RedBlackRotateRight(this, grandpa);
                    }
                } else {
                    uncle = grandpa.L;
                    if (uncle && uncle.C) {
                        parent.C = uncle.C = false;
                        grandpa.C = true;
                        after = grandpa;
                    } else {
                        if (after === parent.L) {
                            RedBlackRotateRight(this, parent);
                            after = parent;
                            parent = after.U;
                        }
                        parent.C = false;
                        grandpa.C = true;
                        RedBlackRotateLeft(this, grandpa);
                    }
                }
                parent = after.U;
            }
            this._.C = false;
        },

        remove: function(node) {
            if (node.N) node.N.P = node.P;
            if (node.P) node.P.N = node.N;
            node.N = node.P = null;

            var parent = node.U,
                sibling,
                left = node.L,
                right = node.R,
                next,
                red;

            if (!left) next = right;
            else if (!right) next = left;
            else next = RedBlackFirst(right);

            if (parent) {
                if (parent.L === node) parent.L = next;
                else parent.R = next;
            } else {
                this._ = next;
            }

            if (left && right) {
                red = next.C;
                next.C = node.C;
                next.L = left;
                left.U = next;
                if (next !== right) {
                    parent = next.U;
                    next.U = node.U;
                    node = next.R;
                    parent.L = node;
                    next.R = right;
                    right.U = next;
                } else {
                    next.U = parent;
                    parent = next;
                    node = next.R;
                }
            } else {
                red = node.C;
                node = next;
            }

            if (node) node.U = parent;
            if (red) return;
            if (node && node.C) { node.C = false; return; }

            do {
                if (node === this._) break;
                if (node === parent.L) {
                    sibling = parent.R;
                    if (sibling.C) {
                        sibling.C = false;
                        parent.C = true;
                        RedBlackRotateLeft(this, parent);
                        sibling = parent.R;
                    }
                    if ((sibling.L && sibling.L.C)
                        || (sibling.R && sibling.R.C)) {
                        if (!sibling.R || !sibling.R.C) {
                            sibling.L.C = false;
                            sibling.C = true;
                            RedBlackRotateRight(this, sibling);
                            sibling = parent.R;
                        }
                        sibling.C = parent.C;
                        parent.C = sibling.R.C = false;
                        RedBlackRotateLeft(this, parent);
                        node = this._;
                        break;
                    }
                } else {
                    sibling = parent.L;
                    if (sibling.C) {
                        sibling.C = false;
                        parent.C = true;
                        RedBlackRotateRight(this, parent);
                        sibling = parent.L;
                    }
                    if ((sibling.L && sibling.L.C)
                        || (sibling.R && sibling.R.C)) {
                        if (!sibling.L || !sibling.L.C) {
                            sibling.R.C = false;
                            sibling.C = true;
                            RedBlackRotateLeft(this, sibling);
                            sibling = parent.L;
                        }
                        sibling.C = parent.C;
                        parent.C = sibling.L.C = false;
                        RedBlackRotateRight(this, parent);
                        node = this._;
                        break;
                    }
                }
                sibling.C = true;
                node = parent;
                parent = parent.U;
            } while (!node.C);

            if (node) node.C = false;
        }
    };

    function RedBlackRotateLeft(tree, node) {
        var p = node,
            q = node.R,
            parent = p.U;

        if (parent) {
            if (parent.L === p) parent.L = q;
            else parent.R = q;
        } else {
            tree._ = q;
        }

        q.U = parent;
        p.U = q;
        p.R = q.L;
        if (p.R) p.R.U = p;
        q.L = p;
    }

    function RedBlackRotateRight(tree, node) {
        var p = node,
            q = node.L,
            parent = p.U;

        if (parent) {
            if (parent.L === p) parent.L = q;
            else parent.R = q;
        } else {
            tree._ = q;
        }

        q.U = parent;
        p.U = q;
        p.L = q.R;
        if (p.L) p.L.U = p;
        q.R = p;
    }

    function RedBlackFirst(node) {
        while (node.L) node = node.L;
        return node;
    }

    function createEdge(left, right, v0, v1) {
        var edge = [null, null],
            index = edges.push(edge) - 1;
        edge.left = left;
        edge.right = right;
        if (v0) setEdgeEnd(edge, left, right, v0);
        if (v1) setEdgeEnd(edge, right, left, v1);
        cells[left.index].halfedges.push(index);
        cells[right.index].halfedges.push(index);
        return edge;
    }

    function createBorderEdge(left, v0, v1) {
        var edge = [v0, v1];
        edge.left = left;
        return edge;
    }

    function setEdgeEnd(edge, left, right, vertex) {
        if (!edge[0] && !edge[1]) {
            edge[0] = vertex;
            edge.left = left;
            edge.right = right;
        } else if (edge.left === right) {
            edge[1] = vertex;
        } else {
            edge[0] = vertex;
        }
    }

// Liang–Barsky line clipping.
    function clipEdge(edge, x0, y0, x1, y1) {
        var a = edge[0],
            b = edge[1],
            ax = a[0],
            ay = a[1],
            bx = b[0],
            by = b[1],
            t0 = 0,
            t1 = 1,
            dx = bx - ax,
            dy = by - ay,
            r;

        r = x0 - ax;
        if (!dx && r > 0) return;
        r /= dx;
        if (dx < 0) {
            if (r < t0) return;
            if (r < t1) t1 = r;
        } else if (dx > 0) {
            if (r > t1) return;
            if (r > t0) t0 = r;
        }

        r = x1 - ax;
        if (!dx && r < 0) return;
        r /= dx;
        if (dx < 0) {
            if (r > t1) return;
            if (r > t0) t0 = r;
        } else if (dx > 0) {
            if (r < t0) return;
            if (r < t1) t1 = r;
        }

        r = y0 - ay;
        if (!dy && r > 0) return;
        r /= dy;
        if (dy < 0) {
            if (r < t0) return;
            if (r < t1) t1 = r;
        } else if (dy > 0) {
            if (r > t1) return;
            if (r > t0) t0 = r;
        }

        r = y1 - ay;
        if (!dy && r < 0) return;
        r /= dy;
        if (dy < 0) {
            if (r > t1) return;
            if (r > t0) t0 = r;
        } else if (dy > 0) {
            if (r < t0) return;
            if (r < t1) t1 = r;
        }

        if (!(t0 > 0) && !(t1 < 1)) return true; // TODO Better check?

        if (t0 > 0) edge[0] = [ax + t0 * dx, ay + t0 * dy];
        if (t1 < 1) edge[1] = [ax + t1 * dx, ay + t1 * dy];
        return true;
    }

    function connectEdge(edge, x0, y0, x1, y1) {
        var v1 = edge[1];
        if (v1) return true;

        var v0 = edge[0],
            left = edge.left,
            right = edge.right,
            lx = left[0],
            ly = left[1],
            rx = right[0],
            ry = right[1],
            fx = (lx + rx) / 2,
            fy = (ly + ry) / 2,
            fm,
            fb;

        if (ry === ly) {
            if (fx < x0 || fx >= x1) return;
            if (lx > rx) {
                if (!v0) v0 = [fx, y0];
                else if (v0[1] >= y1) return;
                v1 = [fx, y1];
            } else {
                if (!v0) v0 = [fx, y1];
                else if (v0[1] < y0) return;
                v1 = [fx, y0];
            }
        } else {
            fm = (lx - rx) / (ry - ly);
            fb = fy - fm * fx;
            if (fm < -1 || fm > 1) {
                if (lx > rx) {
                    if (!v0) v0 = [(y0 - fb) / fm, y0];
                    else if (v0[1] >= y1) return;
                    v1 = [(y1 - fb) / fm, y1];
                } else {
                    if (!v0) v0 = [(y1 - fb) / fm, y1];
                    else if (v0[1] < y0) return;
                    v1 = [(y0 - fb) / fm, y0];
                }
            } else {
                if (ly < ry) {
                    if (!v0) v0 = [x0, fm * x0 + fb];
                    else if (v0[0] >= x1) return;
                    v1 = [x1, fm * x1 + fb];
                } else {
                    if (!v0) v0 = [x1, fm * x1 + fb];
                    else if (v0[0] < x0) return;
                    v1 = [x0, fm * x0 + fb];
                }
            }
        }

        edge[0] = v0;
        edge[1] = v1;
        return true;
    }

    function clipEdges(x0, y0, x1, y1) {
        var i = edges.length,
            edge;

        while (i--) {
            if (!connectEdge(edge = edges[i], x0, y0, x1, y1)
                || !clipEdge(edge, x0, y0, x1, y1)
                || !(Math.abs(edge[0][0] - edge[1][0]) > epsilon$4
                    || Math.abs(edge[0][1] - edge[1][1]) > epsilon$4)) {
                delete edges[i];
            }
        }
    }

    function createCell(site) {
        return cells[site.index] = {
            site: site,
            halfedges: []
        };
    }

    function cellHalfedgeAngle(cell, edge) {
        var site = cell.site,
            va = edge.left,
            vb = edge.right;
        if (site === vb) vb = va, va = site;
        if (vb) return Math.atan2(vb[1] - va[1], vb[0] - va[0]);
        if (site === va) va = edge[1], vb = edge[0];
        else va = edge[0], vb = edge[1];
        return Math.atan2(va[0] - vb[0], vb[1] - va[1]);
    }

    function cellHalfedgeStart(cell, edge) {
        return edge[+(edge.left !== cell.site)];
    }

    function cellHalfedgeEnd(cell, edge) {
        return edge[+(edge.left === cell.site)];
    }

    function sortCellHalfedges() {
        for (var i = 0, n = cells.length, cell, halfedges, j, m; i < n; ++i) {
            if ((cell = cells[i]) && (m = (halfedges = cell.halfedges).length)) {
                var index = new Array(m),
                    array = new Array(m);
                for (j = 0; j < m; ++j) index[j] = j, array[j] = cellHalfedgeAngle(cell, edges[halfedges[j]]);
                index.sort(function(i, j) { return array[j] - array[i]; });
                for (j = 0; j < m; ++j) array[j] = halfedges[index[j]];
                for (j = 0; j < m; ++j) halfedges[j] = array[j];
            }
        }
    }

    function clipCells(x0, y0, x1, y1) {
        var nCells = cells.length,
            iCell,
            cell,
            site,
            iHalfedge,
            halfedges,
            nHalfedges,
            start,
            startX,
            startY,
            end,
            endX,
            endY,
            cover = true;

        for (iCell = 0; iCell < nCells; ++iCell) {
            if (cell = cells[iCell]) {
                site = cell.site;
                halfedges = cell.halfedges;
                iHalfedge = halfedges.length;

                // Remove any dangling clipped edges.
                while (iHalfedge--) {
                    if (!edges[halfedges[iHalfedge]]) {
                        halfedges.splice(iHalfedge, 1);
                    }
                }

                // Insert any border edges as necessary.
                iHalfedge = 0, nHalfedges = halfedges.length;
                while (iHalfedge < nHalfedges) {
                    end = cellHalfedgeEnd(cell, edges[halfedges[iHalfedge]]), endX = end[0], endY = end[1];
                    start = cellHalfedgeStart(cell, edges[halfedges[++iHalfedge % nHalfedges]]), startX = start[0], startY = start[1];
                    if (Math.abs(endX - startX) > epsilon$4 || Math.abs(endY - startY) > epsilon$4) {
                        halfedges.splice(iHalfedge, 0, edges.push(createBorderEdge(site, end,
                            Math.abs(endX - x0) < epsilon$4 && y1 - endY > epsilon$4 ? [x0, Math.abs(startX - x0) < epsilon$4 ? startY : y1]
                                : Math.abs(endY - y1) < epsilon$4 && x1 - endX > epsilon$4 ? [Math.abs(startY - y1) < epsilon$4 ? startX : x1, y1]
                                : Math.abs(endX - x1) < epsilon$4 && endY - y0 > epsilon$4 ? [x1, Math.abs(startX - x1) < epsilon$4 ? startY : y0]
                                    : Math.abs(endY - y0) < epsilon$4 && endX - x0 > epsilon$4 ? [Math.abs(startY - y0) < epsilon$4 ? startX : x0, y0]
                                        : null)) - 1);
                        ++nHalfedges;
                    }
                }

                if (nHalfedges) cover = false;
            }
        }

        // If there weren’t any edges, have the closest site cover the extent.
        // It doesn’t matter which corner of the extent we measure!
        if (cover) {
            var dx, dy, d2, dc = Infinity;

            for (iCell = 0, cover = null; iCell < nCells; ++iCell) {
                if (cell = cells[iCell]) {
                    site = cell.site;
                    dx = site[0] - x0;
                    dy = site[1] - y0;
                    d2 = dx * dx + dy * dy;
                    if (d2 < dc) dc = d2, cover = cell;
                }
            }

            if (cover) {
                var v00 = [x0, y0], v01 = [x0, y1], v11 = [x1, y1], v10 = [x1, y0];
                cover.halfedges.push(
                    edges.push(createBorderEdge(site = cover.site, v00, v01)) - 1,
                    edges.push(createBorderEdge(site, v01, v11)) - 1,
                    edges.push(createBorderEdge(site, v11, v10)) - 1,
                    edges.push(createBorderEdge(site, v10, v00)) - 1
                );
            }
        }

        // Lastly delete any cells with no edges; these were entirely clipped.
        for (iCell = 0; iCell < nCells; ++iCell) {
            if (cell = cells[iCell]) {
                if (!cell.halfedges.length) {
                    delete cells[iCell];
                }
            }
        }
    }

    var circlePool = [];

    var firstCircle;

    function Circle() {
        RedBlackNode(this);
        this.x =
            this.y =
                this.arc =
                    this.site =
                        this.cy = null;
    }

    function attachCircle(arc) {
        var lArc = arc.P,
            rArc = arc.N;

        if (!lArc || !rArc) return;

        var lSite = lArc.site,
            cSite = arc.site,
            rSite = rArc.site;

        if (lSite === rSite) return;

        var bx = cSite[0],
            by = cSite[1],
            ax = lSite[0] - bx,
            ay = lSite[1] - by,
            cx = rSite[0] - bx,
            cy = rSite[1] - by;

        var d = 2 * (ax * cy - ay * cx);
        if (d >= -epsilon2$2) return;

        var ha = ax * ax + ay * ay,
            hc = cx * cx + cy * cy,
            x = (cy * ha - ay * hc) / d,
            y = (ax * hc - cx * ha) / d;

        var circle = circlePool.pop() || new Circle;
        circle.arc = arc;
        circle.site = cSite;
        circle.x = x + bx;
        circle.y = (circle.cy = y + by) + Math.sqrt(x * x + y * y); // y bottom

        arc.circle = circle;

        var before = null,
            node = circles._;

        while (node) {
            if (circle.y < node.y || (circle.y === node.y && circle.x <= node.x)) {
                if (node.L) node = node.L;
                else { before = node.P; break; }
            } else {
                if (node.R) node = node.R;
                else { before = node; break; }
            }
        }

        circles.insert(before, circle);
        if (!before) firstCircle = circle;
    }

    function detachCircle(arc) {
        var circle = arc.circle;
        if (circle) {
            if (!circle.P) firstCircle = circle.N;
            circles.remove(circle);
            circlePool.push(circle);
            RedBlackNode(circle);
            arc.circle = null;
        }
    }

    var beachPool = [];

    function Beach() {
        RedBlackNode(this);
        this.edge =
            this.site =
                this.circle = null;
    }

    function createBeach(site) {
        var beach = beachPool.pop() || new Beach;
        beach.site = site;
        return beach;
    }

    function detachBeach(beach) {
        detachCircle(beach);
        beaches.remove(beach);
        beachPool.push(beach);
        RedBlackNode(beach);
    }

    function removeBeach(beach) {
        var circle = beach.circle,
            x = circle.x,
            y = circle.cy,
            vertex = [x, y],
            previous = beach.P,
            next = beach.N,
            disappearing = [beach];

        detachBeach(beach);

        var lArc = previous;
        while (lArc.circle
        && Math.abs(x - lArc.circle.x) < epsilon$4
        && Math.abs(y - lArc.circle.cy) < epsilon$4) {
            previous = lArc.P;
            disappearing.unshift(lArc);
            detachBeach(lArc);
            lArc = previous;
        }

        disappearing.unshift(lArc);
        detachCircle(lArc);

        var rArc = next;
        while (rArc.circle
        && Math.abs(x - rArc.circle.x) < epsilon$4
        && Math.abs(y - rArc.circle.cy) < epsilon$4) {
            next = rArc.N;
            disappearing.push(rArc);
            detachBeach(rArc);
            rArc = next;
        }

        disappearing.push(rArc);
        detachCircle(rArc);

        var nArcs = disappearing.length,
            iArc;
        for (iArc = 1; iArc < nArcs; ++iArc) {
            rArc = disappearing[iArc];
            lArc = disappearing[iArc - 1];
            setEdgeEnd(rArc.edge, lArc.site, rArc.site, vertex);
        }

        lArc = disappearing[0];
        rArc = disappearing[nArcs - 1];
        rArc.edge = createEdge(lArc.site, rArc.site, null, vertex);

        attachCircle(lArc);
        attachCircle(rArc);
    }

    function addBeach(site) {
        var x = site[0],
            directrix = site[1],
            lArc,
            rArc,
            dxl,
            dxr,
            node = beaches._;

        while (node) {
            dxl = leftBreakPoint(node, directrix) - x;
            if (dxl > epsilon$4) node = node.L; else {
                dxr = x - rightBreakPoint(node, directrix);
                if (dxr > epsilon$4) {
                    if (!node.R) {
                        lArc = node;
                        break;
                    }
                    node = node.R;
                } else {
                    if (dxl > -epsilon$4) {
                        lArc = node.P;
                        rArc = node;
                    } else if (dxr > -epsilon$4) {
                        lArc = node;
                        rArc = node.N;
                    } else {
                        lArc = rArc = node;
                    }
                    break;
                }
            }
        }

        createCell(site);
        var newArc = createBeach(site);
        beaches.insert(lArc, newArc);

        if (!lArc && !rArc) return;

        if (lArc === rArc) {
            detachCircle(lArc);
            rArc = createBeach(lArc.site);
            beaches.insert(newArc, rArc);
            newArc.edge = rArc.edge = createEdge(lArc.site, newArc.site);
            attachCircle(lArc);
            attachCircle(rArc);
            return;
        }

        if (!rArc) { // && lArc
            newArc.edge = createEdge(lArc.site, newArc.site);
            return;
        }

        // else lArc !== rArc
        detachCircle(lArc);
        detachCircle(rArc);

        var lSite = lArc.site,
            ax = lSite[0],
            ay = lSite[1],
            bx = site[0] - ax,
            by = site[1] - ay,
            rSite = rArc.site,
            cx = rSite[0] - ax,
            cy = rSite[1] - ay,
            d = 2 * (bx * cy - by * cx),
            hb = bx * bx + by * by,
            hc = cx * cx + cy * cy,
            vertex = [(cy * hb - by * hc) / d + ax, (bx * hc - cx * hb) / d + ay];

        setEdgeEnd(rArc.edge, lSite, rSite, vertex);
        newArc.edge = createEdge(lSite, site, null, vertex);
        rArc.edge = createEdge(site, rSite, null, vertex);
        attachCircle(lArc);
        attachCircle(rArc);
    }

    function leftBreakPoint(arc, directrix) {
        var site = arc.site,
            rfocx = site[0],
            rfocy = site[1],
            pby2 = rfocy - directrix;

        if (!pby2) return rfocx;

        var lArc = arc.P;
        if (!lArc) return -Infinity;

        site = lArc.site;
        var lfocx = site[0],
            lfocy = site[1],
            plby2 = lfocy - directrix;

        if (!plby2) return lfocx;

        var hl = lfocx - rfocx,
            aby2 = 1 / pby2 - 1 / plby2,
            b = hl / plby2;

        if (aby2) return (-b + Math.sqrt(b * b - 2 * aby2 * (hl * hl / (-2 * plby2) - lfocy + plby2 / 2 + rfocy - pby2 / 2))) / aby2 + rfocx;

        return (rfocx + lfocx) / 2;
    }

    function rightBreakPoint(arc, directrix) {
        var rArc = arc.N;
        if (rArc) return leftBreakPoint(rArc, directrix);
        var site = arc.site;
        return site[1] === directrix ? site[0] : Infinity;
    }

    var epsilon$4 = 1e-6;
    var epsilon2$2 = 1e-12;
    var beaches;
    var cells;
    var circles;
    var edges;

    function triangleArea(a, b, c) {
        return (a[0] - c[0]) * (b[1] - a[1]) - (a[0] - b[0]) * (c[1] - a[1]);
    }

    function lexicographic(a, b) {
        return b[1] - a[1]
            || b[0] - a[0];
    }

    function Diagram(sites, extent) {
        var site = sites.sort(lexicographic).pop(),
            x,
            y,
            circle;

        edges = [];
        cells = new Array(sites.length);
        beaches = new RedBlackTree;
        circles = new RedBlackTree;

        while (true) {
            circle = firstCircle;
            if (site && (!circle || site[1] < circle.y || (site[1] === circle.y && site[0] < circle.x))) {
                if (site[0] !== x || site[1] !== y) {
                    addBeach(site);
                    x = site[0], y = site[1];
                }
                site = sites.pop();
            } else if (circle) {
                removeBeach(circle.arc);
            } else {
                break;
            }
        }

        sortCellHalfedges();

        if (extent) {
            var x0 = +extent[0][0],
                y0 = +extent[0][1],
                x1 = +extent[1][0],
                y1 = +extent[1][1];
            clipEdges(x0, y0, x1, y1);
            clipCells(x0, y0, x1, y1);
        }

        this.edges = edges;
        this.cells = cells;

        beaches =
            circles =
                edges =
                    cells = null;
    }

    Diagram.prototype = {
        constructor: Diagram,

        polygons: function() {
            var edges = this.edges;

            return this.cells.map(function(cell) {
                var polygon = cell.halfedges.map(function(i) { return cellHalfedgeStart(cell, edges[i]); });
                polygon.data = cell.site.data;
                return polygon;
            });
        },

        triangles: function() {
            var triangles = [],
                edges = this.edges;

            this.cells.forEach(function(cell, i) {
                if (!(m = (halfedges = cell.halfedges).length)) return;
                var site = cell.site,
                    halfedges,
                    j = -1,
                    m,
                    s0,
                    e1 = edges[halfedges[m - 1]],
                    s1 = e1.left === site ? e1.right : e1.left;

                while (++j < m) {
                    s0 = s1;
                    e1 = edges[halfedges[j]];
                    s1 = e1.left === site ? e1.right : e1.left;
                    if (s0 && s1 && i < s0.index && i < s1.index && triangleArea(site, s0, s1) < 0) {
                        triangles.push([site.data, s0.data, s1.data]);
                    }
                }
            });

            return triangles;
        },

        links: function() {
            return this.edges.filter(function(edge) {
                return edge.right;
            }).map(function(edge) {
                return {
                    source: edge.left.data,
                    target: edge.right.data
                };
            });
        },

        find: function(x, y, radius) {
            var that = this, i0, i1 = that._found || 0, n = that.cells.length, cell;

            // Use the previously-found cell, or start with an arbitrary one.
            while (!(cell = that.cells[i1])) if (++i1 >= n) return null;
            var dx = x - cell.site[0], dy = y - cell.site[1], d2 = dx * dx + dy * dy;

            // Traverse the half-edges to find a closer cell, if any.
            do {
                cell = that.cells[i0 = i1], i1 = null;
                cell.halfedges.forEach(function(e) {
                    var edge = that.edges[e], v = edge.left;
                    if ((v === cell.site || !v) && !(v = edge.right)) return;
                    var vx = x - v[0], vy = y - v[1], v2 = vx * vx + vy * vy;
                    if (v2 < d2) d2 = v2, i1 = v.index;
                });
            } while (i1 !== null);

            that._found = i0;

            return radius == null || d2 <= radius * radius ? cell.site : null;
        }
    };

    function voronoi() {
        var x$$1 = x$4,
            y$$1 = y$4,
            extent = null;

        function voronoi(data) {
            return new Diagram(data.map(function(d, i) {
                var s = [Math.round(x$$1(d, i, data) / epsilon$4) * epsilon$4, Math.round(y$$1(d, i, data) / epsilon$4) * epsilon$4];
                s.index = i;
                s.data = d;
                return s;
            }), extent);
        }

        voronoi.polygons = function(data) {
            return voronoi(data).polygons();
        };

        voronoi.links = function(data) {
            return voronoi(data).links();
        };

        voronoi.triangles = function(data) {
            return voronoi(data).triangles();
        };

        voronoi.x = function(_) {
            return arguments.length ? (x$$1 = typeof _ === "function" ? _ : constant$11(+_), voronoi) : x$$1;
        };

        voronoi.y = function(_) {
            return arguments.length ? (y$$1 = typeof _ === "function" ? _ : constant$11(+_), voronoi) : y$$1;
        };

        voronoi.extent = function(_) {
            return arguments.length ? (extent = _ == null ? null : [[+_[0][0], +_[0][1]], [+_[1][0], +_[1][1]]], voronoi) : extent && [[extent[0][0], extent[0][1]], [extent[1][0], extent[1][1]]];
        };

        voronoi.size = function(_) {
            return arguments.length ? (extent = _ == null ? null : [[0, 0], [+_[0], +_[1]]], voronoi) : extent && [extent[1][0] - extent[0][0], extent[1][1] - extent[0][1]];
        };

        return voronoi;
    }

    function constant$12(x) {
        return function() {
            return x;
        };
    }

    function ZoomEvent(target, type, transform) {
        this.target = target;
        this.type = type;
        this.transform = transform;
    }

    function Transform(k, x, y) {
        this.k = k;
        this.x = x;
        this.y = y;
    }

    Transform.prototype = {
        constructor: Transform,
        scale: function(k) {
            return k === 1 ? this : new Transform(this.k * k, this.x, this.y);
        },
        translate: function(x, y) {
            return x === 0 & y === 0 ? this : new Transform(this.k, this.x + this.k * x, this.y + this.k * y);
        },
        apply: function(point) {
            return [point[0] * this.k + this.x, point[1] * this.k + this.y];
        },
        applyX: function(x) {
            return x * this.k + this.x;
        },
        applyY: function(y) {
            return y * this.k + this.y;
        },
        invert: function(location) {
            return [(location[0] - this.x) / this.k, (location[1] - this.y) / this.k];
        },
        invertX: function(x) {
            return (x - this.x) / this.k;
        },
        invertY: function(y) {
            return (y - this.y) / this.k;
        },
        rescaleX: function(x) {
            return x.copy().domain(x.range().map(this.invertX, this).map(x.invert, x));
        },
        rescaleY: function(y) {
            return y.copy().domain(y.range().map(this.invertY, this).map(y.invert, y));
        },
        toString: function() {
            return "translate(" + this.x + "," + this.y + ") scale(" + this.k + ")";
        }
    };

    var identity$8 = new Transform(1, 0, 0);

    transform$1.prototype = Transform.prototype;

    function transform$1(node) {
        return node.__zoom || identity$8;
    }

    function nopropagation$2() {
        exports.event.stopImmediatePropagation();
    }

    function noevent$2() {
        exports.event.preventDefault();
        exports.event.stopImmediatePropagation();
    }

// Ignore right-click, since that should open the context menu.
    function defaultFilter$2() {
        return !exports.event.button;
    }

    function defaultExtent$1() {
        var e = this, w, h;
        if (e instanceof SVGElement) {
            e = e.ownerSVGElement || e;
            w = e.width.baseVal.value;
            h = e.height.baseVal.value;
        } else {
            w = e.clientWidth;
            h = e.clientHeight;
        }
        return [[0, 0], [w, h]];
    }

    function defaultTransform() {
        return this.__zoom || identity$8;
    }

    function defaultWheelDelta() {
        return -exports.event.deltaY * (exports.event.deltaMode ? 120 : 1) / 500;
    }

    function defaultTouchable$1() {
        return "ontouchstart" in this;
    }

    function defaultConstrain(transform$$1, extent, translateExtent) {
        var dx0 = transform$$1.invertX(extent[0][0]) - translateExtent[0][0],
            dx1 = transform$$1.invertX(extent[1][0]) - translateExtent[1][0],
            dy0 = transform$$1.invertY(extent[0][1]) - translateExtent[0][1],
            dy1 = transform$$1.invertY(extent[1][1]) - translateExtent[1][1];
        return transform$$1.translate(
            dx1 > dx0 ? (dx0 + dx1) / 2 : Math.min(0, dx0) || Math.max(0, dx1),
            dy1 > dy0 ? (dy0 + dy1) / 2 : Math.min(0, dy0) || Math.max(0, dy1)
        );
    }

    function zoom() {
        var filter = defaultFilter$2,
            extent = defaultExtent$1,
            constrain = defaultConstrain,
            wheelDelta = defaultWheelDelta,
            touchable = defaultTouchable$1,
            scaleExtent = [0, Infinity],
            translateExtent = [[-Infinity, -Infinity], [Infinity, Infinity]],
            duration = 250,
            interpolate = interpolateZoom,
            gestures = [],
            listeners = dispatch("start", "zoom", "end"),
            touchstarting,
            touchending,
            touchDelay = 500,
            wheelDelay = 150,
            clickDistance2 = 0;

        function zoom(selection) {
            selection
                .property("__zoom", defaultTransform)
                .on("wheel.zoom", wheeled)
                .on("mousedown.zoom", mousedowned)
                .on("dblclick.zoom", dblclicked)
                .filter(touchable)
                .on("touchstart.zoom", touchstarted)
                .on("touchmove.zoom", touchmoved)
                .on("touchend.zoom touchcancel.zoom", touchended)
                .style("touch-action", "none")
                .style("-webkit-tap-highlight-color", "rgba(0,0,0,0)");
        }

        zoom.transform = function(collection, transform$$1) {
            var selection = collection.selection ? collection.selection() : collection;
            selection.property("__zoom", defaultTransform);
            if (collection !== selection) {
                schedule(collection, transform$$1);
            } else {
                selection.interrupt().each(function() {
                    gesture(this, arguments)
                        .start()
                        .zoom(null, typeof transform$$1 === "function" ? transform$$1.apply(this, arguments) : transform$$1)
                        .end();
                });
            }
        };

        zoom.scaleBy = function(selection, k) {
            zoom.scaleTo(selection, function() {
                var k0 = this.__zoom.k,
                    k1 = typeof k === "function" ? k.apply(this, arguments) : k;
                return k0 * k1;
            });
        };

        zoom.scaleTo = function(selection, k) {
            zoom.transform(selection, function() {
                var e = extent.apply(this, arguments),
                    t0 = this.__zoom,
                    p0 = centroid(e),
                    p1 = t0.invert(p0),
                    k1 = typeof k === "function" ? k.apply(this, arguments) : k;
                return constrain(translate(scale(t0, k1), p0, p1), e, translateExtent);
            });
        };

        zoom.translateBy = function(selection, x, y) {
            zoom.transform(selection, function() {
                return constrain(this.__zoom.translate(
                    typeof x === "function" ? x.apply(this, arguments) : x,
                    typeof y === "function" ? y.apply(this, arguments) : y
                ), extent.apply(this, arguments), translateExtent);
            });
        };

        zoom.translateTo = function(selection, x, y) {
            zoom.transform(selection, function() {
                var e = extent.apply(this, arguments),
                    t = this.__zoom,
                    p = centroid(e);
                return constrain(identity$8.translate(p[0], p[1]).scale(t.k).translate(
                    typeof x === "function" ? -x.apply(this, arguments) : -x,
                    typeof y === "function" ? -y.apply(this, arguments) : -y
                ), e, translateExtent);
            });
        };

        function scale(transform$$1, k) {
            k = Math.max(scaleExtent[0], Math.min(scaleExtent[1], k));
            return k === transform$$1.k ? transform$$1 : new Transform(k, transform$$1.x, transform$$1.y);
        }

        function translate(transform$$1, p0, p1) {
            var x = p0[0] - p1[0] * transform$$1.k, y = p0[1] - p1[1] * transform$$1.k;
            return x === transform$$1.x && y === transform$$1.y ? transform$$1 : new Transform(transform$$1.k, x, y);
        }

        function centroid(extent) {
            return [(+extent[0][0] + +extent[1][0]) / 2, (+extent[0][1] + +extent[1][1]) / 2];
        }

        function schedule(transition, transform$$1, center) {
            transition
                .on("start.zoom", function() { gesture(this, arguments).start(); })
                .on("interrupt.zoom end.zoom", function() { gesture(this, arguments).end(); })
                .tween("zoom", function() {
                    var that = this,
                        args = arguments,
                        g = gesture(that, args),
                        e = extent.apply(that, args),
                        p = center || centroid(e),
                        w = Math.max(e[1][0] - e[0][0], e[1][1] - e[0][1]),
                        a = that.__zoom,
                        b = typeof transform$$1 === "function" ? transform$$1.apply(that, args) : transform$$1,
                        i = interpolate(a.invert(p).concat(w / a.k), b.invert(p).concat(w / b.k));
                    return function(t) {
                        if (t === 1) t = b; // Avoid rounding error on end.
                        else { var l = i(t), k = w / l[2]; t = new Transform(k, p[0] - l[0] * k, p[1] - l[1] * k); }
                        g.zoom(null, t);
                    };
                });
        }

        function gesture(that, args) {
            for (var i = 0, n = gestures.length, g; i < n; ++i) {
                if ((g = gestures[i]).that === that) {
                    return g;
                }
            }
            return new Gesture(that, args);
        }

        function Gesture(that, args) {
            this.that = that;
            this.args = args;
            this.index = -1;
            this.active = 0;
            this.extent = extent.apply(that, args);
        }

        Gesture.prototype = {
            start: function() {
                if (++this.active === 1) {
                    this.index = gestures.push(this) - 1;
                    this.emit("start");
                }
                return this;
            },
            zoom: function(key, transform$$1) {
                if (this.mouse && key !== "mouse") this.mouse[1] = transform$$1.invert(this.mouse[0]);
                if (this.touch0 && key !== "touch") this.touch0[1] = transform$$1.invert(this.touch0[0]);
                if (this.touch1 && key !== "touch") this.touch1[1] = transform$$1.invert(this.touch1[0]);
                this.that.__zoom = transform$$1;
                this.emit("zoom");
                return this;
            },
            end: function() {
                if (--this.active === 0) {
                    gestures.splice(this.index, 1);
                    this.index = -1;
                    this.emit("end");
                }
                return this;
            },
            emit: function(type) {
                customEvent(new ZoomEvent(zoom, type, this.that.__zoom), listeners.apply, listeners, [type, this.that, this.args]);
            }
        };

        function wheeled() {
            if (!filter.apply(this, arguments)) return;
            var g = gesture(this, arguments),
                t = this.__zoom,
                k = Math.max(scaleExtent[0], Math.min(scaleExtent[1], t.k * Math.pow(2, wheelDelta.apply(this, arguments)))),
                p = mouse(this);

            // If the mouse is in the same location as before, reuse it.
            // If there were recent wheel events, reset the wheel idle timeout.
            if (g.wheel) {
                if (g.mouse[0][0] !== p[0] || g.mouse[0][1] !== p[1]) {
                    g.mouse[1] = t.invert(g.mouse[0] = p);
                }
                clearTimeout(g.wheel);
            }

            // If this wheel event won’t trigger a transform change, ignore it.
            else if (t.k === k) return;

            // Otherwise, capture the mouse point and location at the start.
            else {
                g.mouse = [p, t.invert(p)];
                interrupt(this);
                g.start();
            }

            noevent$2();
            g.wheel = setTimeout(wheelidled, wheelDelay);
            g.zoom("mouse", constrain(translate(scale(t, k), g.mouse[0], g.mouse[1]), g.extent, translateExtent));

            function wheelidled() {
                g.wheel = null;
                g.end();
            }
        }

        function mousedowned() {
            if (touchending || !filter.apply(this, arguments)) return;
            var g = gesture(this, arguments),
                v = select(exports.event.view).on("mousemove.zoom", mousemoved, true).on("mouseup.zoom", mouseupped, true),
                p = mouse(this),
                x0 = exports.event.clientX,
                y0 = exports.event.clientY;

            dragDisable(exports.event.view);
            nopropagation$2();
            g.mouse = [p, this.__zoom.invert(p)];
            interrupt(this);
            g.start();

            function mousemoved() {
                noevent$2();
                if (!g.moved) {
                    var dx = exports.event.clientX - x0, dy = exports.event.clientY - y0;
                    g.moved = dx * dx + dy * dy > clickDistance2;
                }
                g.zoom("mouse", constrain(translate(g.that.__zoom, g.mouse[0] = mouse(g.that), g.mouse[1]), g.extent, translateExtent));
            }

            function mouseupped() {
                v.on("mousemove.zoom mouseup.zoom", null);
                yesdrag(exports.event.view, g.moved);
                noevent$2();
                g.end();
            }
        }

        function dblclicked() {
            if (!filter.apply(this, arguments)) return;
            var t0 = this.__zoom,
                p0 = mouse(this),
                p1 = t0.invert(p0),
                k1 = t0.k * (exports.event.shiftKey ? 0.5 : 2),
                t1 = constrain(translate(scale(t0, k1), p0, p1), extent.apply(this, arguments), translateExtent);

            noevent$2();
            if (duration > 0) select(this).transition().duration(duration).call(schedule, t1, p0);
            else select(this).call(zoom.transform, t1);
        }

        function touchstarted() {
            if (!filter.apply(this, arguments)) return;
            var g = gesture(this, arguments),
                touches = exports.event.changedTouches,
                started,
                n = touches.length, i, t, p;

            nopropagation$2();
            for (i = 0; i < n; ++i) {
                t = touches[i], p = touch(this, touches, t.identifier);
                p = [p, this.__zoom.invert(p), t.identifier];
                if (!g.touch0) g.touch0 = p, started = true;
                else if (!g.touch1) g.touch1 = p;
            }

            // If this is a dbltap, reroute to the (optional) dblclick.zoom handler.
            if (touchstarting) {
                touchstarting = clearTimeout(touchstarting);
                if (!g.touch1) {
                    g.end();
                    p = select(this).on("dblclick.zoom");
                    if (p) p.apply(this, arguments);
                    return;
                }
            }

            if (started) {
                touchstarting = setTimeout(function() { touchstarting = null; }, touchDelay);
                interrupt(this);
                g.start();
            }
        }

        function touchmoved() {
            var g = gesture(this, arguments),
                touches = exports.event.changedTouches,
                n = touches.length, i, t, p, l;

            noevent$2();
            if (touchstarting) touchstarting = clearTimeout(touchstarting);
            for (i = 0; i < n; ++i) {
                t = touches[i], p = touch(this, touches, t.identifier);
                if (g.touch0 && g.touch0[2] === t.identifier) g.touch0[0] = p;
                else if (g.touch1 && g.touch1[2] === t.identifier) g.touch1[0] = p;
            }
            t = g.that.__zoom;
            if (g.touch1) {
                var p0 = g.touch0[0], l0 = g.touch0[1],
                    p1 = g.touch1[0], l1 = g.touch1[1],
                    dp = (dp = p1[0] - p0[0]) * dp + (dp = p1[1] - p0[1]) * dp,
                    dl = (dl = l1[0] - l0[0]) * dl + (dl = l1[1] - l0[1]) * dl;
                t = scale(t, Math.sqrt(dp / dl));
                p = [(p0[0] + p1[0]) / 2, (p0[1] + p1[1]) / 2];
                l = [(l0[0] + l1[0]) / 2, (l0[1] + l1[1]) / 2];
            }
            else if (g.touch0) p = g.touch0[0], l = g.touch0[1];
            else return;
            g.zoom("touch", constrain(translate(t, p, l), g.extent, translateExtent));
        }

        function touchended() {
            var g = gesture(this, arguments),
                touches = exports.event.changedTouches,
                n = touches.length, i, t;

            nopropagation$2();
            if (touchending) clearTimeout(touchending);
            touchending = setTimeout(function() { touchending = null; }, touchDelay);
            for (i = 0; i < n; ++i) {
                t = touches[i];
                if (g.touch0 && g.touch0[2] === t.identifier) delete g.touch0;
                else if (g.touch1 && g.touch1[2] === t.identifier) delete g.touch1;
            }
            if (g.touch1 && !g.touch0) g.touch0 = g.touch1, delete g.touch1;
            if (g.touch0) g.touch0[1] = this.__zoom.invert(g.touch0[0]);
            else g.end();
        }

        zoom.wheelDelta = function(_) {
            return arguments.length ? (wheelDelta = typeof _ === "function" ? _ : constant$12(+_), zoom) : wheelDelta;
        };

        zoom.filter = function(_) {
            return arguments.length ? (filter = typeof _ === "function" ? _ : constant$12(!!_), zoom) : filter;
        };

        zoom.touchable = function(_) {
            return arguments.length ? (touchable = typeof _ === "function" ? _ : constant$12(!!_), zoom) : touchable;
        };

        zoom.extent = function(_) {
            return arguments.length ? (extent = typeof _ === "function" ? _ : constant$12([[+_[0][0], +_[0][1]], [+_[1][0], +_[1][1]]]), zoom) : extent;
        };

        zoom.scaleExtent = function(_) {
            return arguments.length ? (scaleExtent[0] = +_[0], scaleExtent[1] = +_[1], zoom) : [scaleExtent[0], scaleExtent[1]];
        };

        zoom.translateExtent = function(_) {
            return arguments.length ? (translateExtent[0][0] = +_[0][0], translateExtent[1][0] = +_[1][0], translateExtent[0][1] = +_[0][1], translateExtent[1][1] = +_[1][1], zoom) : [[translateExtent[0][0], translateExtent[0][1]], [translateExtent[1][0], translateExtent[1][1]]];
        };

        zoom.constrain = function(_) {
            return arguments.length ? (constrain = _, zoom) : constrain;
        };

        zoom.duration = function(_) {
            return arguments.length ? (duration = +_, zoom) : duration;
        };

        zoom.interpolate = function(_) {
            return arguments.length ? (interpolate = _, zoom) : interpolate;
        };

        zoom.on = function() {
            var value = listeners.on.apply(listeners, arguments);
            return value === listeners ? zoom : value;
        };

        zoom.clickDistance = function(_) {
            return arguments.length ? (clickDistance2 = (_ = +_) * _, zoom) : Math.sqrt(clickDistance2);
        };

        return zoom;
    }

    exports.version = version;
    exports.bisect = bisectRight;
    exports.bisectRight = bisectRight;
    exports.bisectLeft = bisectLeft;
    exports.ascending = ascending;
    exports.bisector = bisector;
    exports.cross = cross;
    exports.descending = descending;
    exports.deviation = deviation;
    exports.extent = extent;
    exports.histogram = histogram;
    exports.thresholdFreedmanDiaconis = freedmanDiaconis;
    exports.thresholdScott = scott;
    exports.thresholdSturges = sturges;
    exports.max = max;
    exports.mean = mean;
    exports.median = median;
    exports.merge = merge;
    exports.min = min;
    exports.pairs = pairs;
    exports.permute = permute;
    exports.quantile = threshold;
    exports.range = sequence;
    exports.scan = scan;
    exports.shuffle = shuffle;
    exports.sum = sum;
    exports.ticks = ticks;
    exports.tickIncrement = tickIncrement;
    exports.tickStep = tickStep;
    exports.transpose = transpose;
    exports.variance = variance;
    exports.zip = zip;
    exports.axisTop = axisTop;
    exports.axisRight = axisRight;
    exports.axisBottom = axisBottom;
    exports.axisLeft = axisLeft;
    exports.brush = brush;
    exports.brushX = brushX;
    exports.brushY = brushY;
    exports.brushSelection = brushSelection;
    exports.chord = chord;
    exports.ribbon = ribbon;
    exports.nest = nest;
    exports.set = set$2;
    exports.map = map$1;
    exports.keys = keys;
    exports.values = values;
    exports.entries = entries;
    exports.color = color;
    exports.rgb = rgb;
    exports.hsl = hsl;
    exports.lab = lab;
    exports.hcl = hcl;
    exports.cubehelix = cubehelix;
    exports.dispatch = dispatch;
    exports.drag = drag;
    exports.dragDisable = dragDisable;
    exports.dragEnable = yesdrag;
    exports.dsvFormat = dsv;
    exports.csvParse = csvParse;
    exports.csvParseRows = csvParseRows;
    exports.csvFormat = csvFormat;
    exports.csvFormatRows = csvFormatRows;
    exports.tsvParse = tsvParse;
    exports.tsvParseRows = tsvParseRows;
    exports.tsvFormat = tsvFormat;
    exports.tsvFormatRows = tsvFormatRows;
    exports.easeLinear = linear$1;
    exports.easeQuad = quadInOut;
    exports.easeQuadIn = quadIn;
    exports.easeQuadOut = quadOut;
    exports.easeQuadInOut = quadInOut;
    exports.easeCubic = cubicInOut;
    exports.easeCubicIn = cubicIn;
    exports.easeCubicOut = cubicOut;
    exports.easeCubicInOut = cubicInOut;
    exports.easePoly = polyInOut;
    exports.easePolyIn = polyIn;
    exports.easePolyOut = polyOut;
    exports.easePolyInOut = polyInOut;
    exports.easeSin = sinInOut;
    exports.easeSinIn = sinIn;
    exports.easeSinOut = sinOut;
    exports.easeSinInOut = sinInOut;
    exports.easeExp = expInOut;
    exports.easeExpIn = expIn;
    exports.easeExpOut = expOut;
    exports.easeExpInOut = expInOut;
    exports.easeCircle = circleInOut;
    exports.easeCircleIn = circleIn;
    exports.easeCircleOut = circleOut;
    exports.easeCircleInOut = circleInOut;
    exports.easeBounce = bounceOut;
    exports.easeBounceIn = bounceIn;
    exports.easeBounceOut = bounceOut;
    exports.easeBounceInOut = bounceInOut;
    exports.easeBack = backInOut;
    exports.easeBackIn = backIn;
    exports.easeBackOut = backOut;
    exports.easeBackInOut = backInOut;
    exports.easeElastic = elasticOut;
    exports.easeElasticIn = elasticIn;
    exports.easeElasticOut = elasticOut;
    exports.easeElasticInOut = elasticInOut;
    exports.forceCenter = center$1;
    exports.forceCollide = collide;
    exports.forceLink = link;
    exports.forceManyBody = manyBody;
    exports.forceRadial = radial;
    exports.forceSimulation = simulation;
    exports.forceX = x$2;
    exports.forceY = y$2;
    exports.formatDefaultLocale = defaultLocale;
    exports.formatLocale = formatLocale;
    exports.formatSpecifier = formatSpecifier;
    exports.precisionFixed = precisionFixed;
    exports.precisionPrefix = precisionPrefix;
    exports.precisionRound = precisionRound;
    exports.geoArea = area;
    exports.geoBounds = bounds;
    exports.geoCentroid = centroid;
    exports.geoCircle = circle;
    exports.geoClipAntimeridian = clipAntimeridian;
    exports.geoClipCircle = clipCircle;
    exports.geoClipExtent = extent$1;
    exports.geoClipRectangle = clipRectangle;
    exports.geoContains = contains;
    exports.geoDistance = distance;
    exports.geoGraticule = graticule;
    exports.geoGraticule10 = graticule10;
    exports.geoInterpolate = interpolate$1;
    exports.geoLength = length$1;
    exports.geoPath = index$1;
    exports.geoAlbers = albers;
    exports.geoAlbersUsa = albersUsa;
    exports.geoAzimuthalEqualArea = azimuthalEqualArea;
    exports.geoAzimuthalEqualAreaRaw = azimuthalEqualAreaRaw;
    exports.geoAzimuthalEquidistant = azimuthalEquidistant;
    exports.geoAzimuthalEquidistantRaw = azimuthalEquidistantRaw;
    exports.geoConicConformal = conicConformal;
    exports.geoConicConformalRaw = conicConformalRaw;
    exports.geoConicEqualArea = conicEqualArea;
    exports.geoConicEqualAreaRaw = conicEqualAreaRaw;
    exports.geoConicEquidistant = conicEquidistant;
    exports.geoConicEquidistantRaw = conicEquidistantRaw;
    exports.geoEquirectangular = equirectangular;
    exports.geoEquirectangularRaw = equirectangularRaw;
    exports.geoGnomonic = gnomonic;
    exports.geoGnomonicRaw = gnomonicRaw;
    exports.geoIdentity = identity$5;
    exports.geoProjection = projection;
    exports.geoProjectionMutator = projectionMutator;
    exports.geoMercator = mercator;
    exports.geoMercatorRaw = mercatorRaw;
    exports.geoNaturalEarth1 = naturalEarth1;
    exports.geoNaturalEarth1Raw = naturalEarth1Raw;
    exports.geoOrthographic = orthographic;
    exports.geoOrthographicRaw = orthographicRaw;
    exports.geoStereographic = stereographic;
    exports.geoStereographicRaw = stereographicRaw;
    exports.geoTransverseMercator = transverseMercator;
    exports.geoTransverseMercatorRaw = transverseMercatorRaw;
    exports.geoRotation = rotation;
    exports.geoStream = geoStream;
    exports.geoTransform = transform;
    exports.cluster = cluster;
    exports.hierarchy = hierarchy;
    exports.pack = index$2;
    exports.packSiblings = siblings;
    exports.packEnclose = enclose;
    exports.partition = partition;
    exports.stratify = stratify;
    exports.tree = tree;
    exports.treemap = index$3;
    exports.treemapBinary = binary;
    exports.treemapDice = treemapDice;
    exports.treemapSlice = treemapSlice;
    exports.treemapSliceDice = sliceDice;
    exports.treemapSquarify = squarify;
    exports.treemapResquarify = resquarify;
    exports.interpolate = interpolateValue;
    exports.interpolateArray = array$1;
    exports.interpolateBasis = basis$1;
    exports.interpolateBasisClosed = basisClosed;
    exports.interpolateDate = date;
    exports.interpolateNumber = reinterpolate;
    exports.interpolateObject = object;
    exports.interpolateRound = interpolateRound;
    exports.interpolateString = interpolateString;
    exports.interpolateTransformCss = interpolateTransformCss;
    exports.interpolateTransformSvg = interpolateTransformSvg;
    exports.interpolateZoom = interpolateZoom;
    exports.interpolateRgb = interpolateRgb;
    exports.interpolateRgbBasis = rgbBasis;
    exports.interpolateRgbBasisClosed = rgbBasisClosed;
    exports.interpolateHsl = hsl$2;
    exports.interpolateHslLong = hslLong;
    exports.interpolateLab = lab$1;
    exports.interpolateHcl = hcl$2;
    exports.interpolateHclLong = hclLong;
    exports.interpolateCubehelix = cubehelix$2;
    exports.interpolateCubehelixLong = cubehelixLong;
    exports.quantize = quantize;
    exports.path = path;
    exports.polygonArea = area$1;
    exports.polygonCentroid = centroid$1;
    exports.polygonHull = hull;
    exports.polygonContains = contains$1;
    exports.polygonLength = length$2;
    exports.quadtree = quadtree;
    exports.queue = queue;
    exports.randomUniform = uniform;
    exports.randomNormal = normal;
    exports.randomLogNormal = logNormal;
    exports.randomBates = bates;
    exports.randomIrwinHall = irwinHall;
    exports.randomExponential = exponential$1;
    exports.request = request;
    exports.html = html;
    exports.json = json;
    exports.text = text;
    exports.xml = xml;
    exports.csv = csv$1;
    exports.tsv = tsv$1;
    exports.scaleBand = band;
    exports.scalePoint = point$1;
    exports.scaleIdentity = identity$6;
    exports.scaleLinear = linear$2;
    exports.scaleLog = log$1;
    exports.scaleOrdinal = ordinal;
    exports.scaleImplicit = implicit;
    exports.scalePow = pow$1;
    exports.scaleSqrt = sqrt$1;
    exports.scaleQuantile = quantile$$1;
    exports.scaleQuantize = quantize$1;
    exports.scaleThreshold = threshold$1;
    exports.scaleTime = time;
    exports.scaleUtc = utcTime;
    exports.schemeCategory10 = category10;
    exports.schemeCategory20b = category20b;
    exports.schemeCategory20c = category20c;
    exports.schemeCategory20 = category20;
    exports.interpolateCubehelixDefault = cubehelix$3;
    exports.interpolateRainbow = rainbow$1;
    exports.interpolateWarm = warm;
    exports.interpolateCool = cool;
    exports.interpolateViridis = viridis;
    exports.interpolateMagma = magma;
    exports.interpolateInferno = inferno;
    exports.interpolatePlasma = plasma;
    exports.scaleSequential = sequential;
    exports.create = create;
    exports.creator = creator;
    exports.local = local$1;
    exports.matcher = matcher$1;
    exports.mouse = mouse;
    exports.namespace = namespace;
    exports.namespaces = namespaces;
    exports.clientPoint = point;
    exports.select = select;
    exports.selectAll = selectAll;
    exports.selection = selection;
    exports.selector = selector;
    exports.selectorAll = selectorAll;
    exports.style = styleValue;
    exports.touch = touch;
    exports.touches = touches;
    exports.window = defaultView;
    exports.customEvent = customEvent;
    exports.arc = arc;
    exports.area = area$2;
    exports.line = line;
    exports.pie = pie;
    exports.areaRadial = areaRadial;
    exports.radialArea = areaRadial;
    exports.lineRadial = lineRadial$1;
    exports.radialLine = lineRadial$1;
    exports.pointRadial = pointRadial;
    exports.linkHorizontal = linkHorizontal;
    exports.linkVertical = linkVertical;
    exports.linkRadial = linkRadial;
    exports.symbol = symbol;
    exports.symbols = symbols;
    exports.symbolCircle = circle$2;
    exports.symbolCross = cross$2;
    exports.symbolDiamond = diamond;
    exports.symbolSquare = square;
    exports.symbolStar = star;
    exports.symbolTriangle = triangle;
    exports.symbolWye = wye;
    exports.curveBasisClosed = basisClosed$1;
    exports.curveBasisOpen = basisOpen;
    exports.curveBasis = basis$2;
    exports.curveBundle = bundle;
    exports.curveCardinalClosed = cardinalClosed;
    exports.curveCardinalOpen = cardinalOpen;
    exports.curveCardinal = cardinal;
    exports.curveCatmullRomClosed = catmullRomClosed;
    exports.curveCatmullRomOpen = catmullRomOpen;
    exports.curveCatmullRom = catmullRom;
    exports.curveLinearClosed = linearClosed;
    exports.curveLinear = curveLinear;
    exports.curveMonotoneX = monotoneX;
    exports.curveMonotoneY = monotoneY;
    exports.curveNatural = natural;
    exports.curveStep = step;
    exports.curveStepAfter = stepAfter;
    exports.curveStepBefore = stepBefore;
    exports.stack = stack;
    exports.stackOffsetExpand = expand;
    exports.stackOffsetDiverging = diverging;
    exports.stackOffsetNone = none$1;
    exports.stackOffsetSilhouette = silhouette;
    exports.stackOffsetWiggle = wiggle;
    exports.stackOrderAscending = ascending$2;
    exports.stackOrderDescending = descending$2;
    exports.stackOrderInsideOut = insideOut;
    exports.stackOrderNone = none$2;
    exports.stackOrderReverse = reverse;
    exports.timeInterval = newInterval;
    exports.timeMillisecond = millisecond;
    exports.timeMilliseconds = milliseconds;
    exports.utcMillisecond = millisecond;
    exports.utcMilliseconds = milliseconds;
    exports.timeSecond = second;
    exports.timeSeconds = seconds;
    exports.utcSecond = second;
    exports.utcSeconds = seconds;
    exports.timeMinute = minute;
    exports.timeMinutes = minutes;
    exports.timeHour = hour;
    exports.timeHours = hours;
    exports.timeDay = day;
    exports.timeDays = days;
    exports.timeWeek = sunday;
    exports.timeWeeks = sundays;
    exports.timeSunday = sunday;
    exports.timeSundays = sundays;
    exports.timeMonday = monday;
    exports.timeMondays = mondays;
    exports.timeTuesday = tuesday;
    exports.timeTuesdays = tuesdays;
    exports.timeWednesday = wednesday;
    exports.timeWednesdays = wednesdays;
    exports.timeThursday = thursday;
    exports.timeThursdays = thursdays;
    exports.timeFriday = friday;
    exports.timeFridays = fridays;
    exports.timeSaturday = saturday;
    exports.timeSaturdays = saturdays;
    exports.timeMonth = month;
    exports.timeMonths = months;
    exports.timeYear = year;
    exports.timeYears = years;
    exports.utcMinute = utcMinute;
    exports.utcMinutes = utcMinutes;
    exports.utcHour = utcHour;
    exports.utcHours = utcHours;
    exports.utcDay = utcDay;
    exports.utcDays = utcDays;
    exports.utcWeek = utcSunday;
    exports.utcWeeks = utcSundays;
    exports.utcSunday = utcSunday;
    exports.utcSundays = utcSundays;
    exports.utcMonday = utcMonday;
    exports.utcMondays = utcMondays;
    exports.utcTuesday = utcTuesday;
    exports.utcTuesdays = utcTuesdays;
    exports.utcWednesday = utcWednesday;
    exports.utcWednesdays = utcWednesdays;
    exports.utcThursday = utcThursday;
    exports.utcThursdays = utcThursdays;
    exports.utcFriday = utcFriday;
    exports.utcFridays = utcFridays;
    exports.utcSaturday = utcSaturday;
    exports.utcSaturdays = utcSaturdays;
    exports.utcMonth = utcMonth;
    exports.utcMonths = utcMonths;
    exports.utcYear = utcYear;
    exports.utcYears = utcYears;
    exports.timeFormatDefaultLocale = defaultLocale$1;
    exports.timeFormatLocale = formatLocale$1;
    exports.isoFormat = formatIso;
    exports.isoParse = parseIso;
    exports.now = now;
    exports.timer = timer;
    exports.timerFlush = timerFlush;
    exports.timeout = timeout$1;
    exports.interval = interval$1;
    exports.transition = transition;
    exports.active = active;
    exports.interrupt = interrupt;
    exports.voronoi = voronoi;
    exports.zoom = zoom;
    exports.zoomTransform = transform$1;
    exports.zoomIdentity = identity$8;

    Object.defineProperty(exports, '__esModule', { value: true });

})));