Index: node_modules/d3-scale/dist/d3-scale.js
===================================================================
--- node_modules/d3-scale/dist/d3-scale.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-scale/dist/d3-scale.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,1196 @@
+// https://d3js.org/d3-scale/ v4.0.2 Copyright 2010-2021 Mike Bostock
+(function (global, factory) {
+typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('d3-array'), require('d3-interpolate'), require('d3-format'), require('d3-time'), require('d3-time-format')) :
+typeof define === 'function' && define.amd ? define(['exports', 'd3-array', 'd3-interpolate', 'd3-format', 'd3-time', 'd3-time-format'], factory) :
+(global = typeof globalThis !== 'undefined' ? globalThis : global || self, factory(global.d3 = global.d3 || {}, global.d3, global.d3, global.d3, global.d3, global.d3));
+})(this, (function (exports, d3Array, d3Interpolate, d3Format, d3Time, d3TimeFormat) { 'use strict';
+
+function initRange(domain, range) {
+  switch (arguments.length) {
+    case 0: break;
+    case 1: this.range(domain); break;
+    default: this.range(range).domain(domain); break;
+  }
+  return this;
+}
+
+function initInterpolator(domain, interpolator) {
+  switch (arguments.length) {
+    case 0: break;
+    case 1: {
+      if (typeof domain === "function") this.interpolator(domain);
+      else this.range(domain);
+      break;
+    }
+    default: {
+      this.domain(domain);
+      if (typeof interpolator === "function") this.interpolator(interpolator);
+      else this.range(interpolator);
+      break;
+    }
+  }
+  return this;
+}
+
+const implicit = Symbol("implicit");
+
+function ordinal() {
+  var index = new d3Array.InternMap(),
+      domain = [],
+      range = [],
+      unknown = implicit;
+
+  function scale(d) {
+    let i = index.get(d);
+    if (i === undefined) {
+      if (unknown !== implicit) return unknown;
+      index.set(d, i = domain.push(d) - 1);
+    }
+    return range[i % range.length];
+  }
+
+  scale.domain = function(_) {
+    if (!arguments.length) return domain.slice();
+    domain = [], index = new d3Array.InternMap();
+    for (const value of _) {
+      if (index.has(value)) continue;
+      index.set(value, domain.push(value) - 1);
+    }
+    return scale;
+  };
+
+  scale.range = function(_) {
+    return arguments.length ? (range = Array.from(_), scale) : range.slice();
+  };
+
+  scale.unknown = function(_) {
+    return arguments.length ? (unknown = _, scale) : unknown;
+  };
+
+  scale.copy = function() {
+    return ordinal(domain, range).unknown(unknown);
+  };
+
+  initRange.apply(scale, arguments);
+
+  return scale;
+}
+
+function band() {
+  var scale = ordinal().unknown(undefined),
+      domain = scale.domain,
+      ordinalRange = scale.range,
+      r0 = 0,
+      r1 = 1,
+      step,
+      bandwidth,
+      round = false,
+      paddingInner = 0,
+      paddingOuter = 0,
+      align = 0.5;
+
+  delete scale.unknown;
+
+  function rescale() {
+    var n = domain().length,
+        reverse = r1 < r0,
+        start = reverse ? r1 : r0,
+        stop = reverse ? r0 : r1;
+    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 = d3Array.range(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 ? ([r0, r1] = _, r0 = +r0, r1 = +r1, rescale()) : [r0, r1];
+  };
+
+  scale.rangeRound = function(_) {
+    return [r0, r1] = _, r0 = +r0, r1 = +r1, 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 = Math.min(1, paddingOuter = +_), rescale()) : paddingInner;
+  };
+
+  scale.paddingInner = function(_) {
+    return arguments.length ? (paddingInner = Math.min(1, _), rescale()) : paddingInner;
+  };
+
+  scale.paddingOuter = function(_) {
+    return arguments.length ? (paddingOuter = +_, rescale()) : paddingOuter;
+  };
+
+  scale.align = function(_) {
+    return arguments.length ? (align = Math.max(0, Math.min(1, _)), rescale()) : align;
+  };
+
+  scale.copy = function() {
+    return band(domain(), [r0, r1])
+        .round(round)
+        .paddingInner(paddingInner)
+        .paddingOuter(paddingOuter)
+        .align(align);
+  };
+
+  return initRange.apply(rescale(), arguments);
+}
+
+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() {
+  return pointish(band.apply(null, arguments).paddingInner(1));
+}
+
+function constants(x) {
+  return function() {
+    return x;
+  };
+}
+
+function number$1(x) {
+  return +x;
+}
+
+var unit = [0, 1];
+
+function identity$1(x) {
+  return x;
+}
+
+function normalize(a, b) {
+  return (b -= (a = +a))
+      ? function(x) { return (x - a) / b; }
+      : constants(isNaN(b) ? NaN : 0.5);
+}
+
+function clamper(a, b) {
+  var t;
+  if (a > b) t = a, a = b, b = t;
+  return function(x) { return Math.max(a, Math.min(b, x)); };
+}
+
+// normalize(a, b)(x) takes a domain value x in [a,b] and returns the corresponding parameter t in [0,1].
+// interpolate(a, b)(t) takes a parameter t in [0,1] and returns the corresponding range value x in [a,b].
+function bimap(domain, range, interpolate) {
+  var d0 = domain[0], d1 = domain[1], r0 = range[0], r1 = range[1];
+  if (d1 < d0) d0 = normalize(d1, d0), r0 = interpolate(r1, r0);
+  else d0 = normalize(d0, d1), r0 = interpolate(r0, r1);
+  return function(x) { return r0(d0(x)); };
+}
+
+function polymap(domain, range, interpolate) {
+  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] = normalize(domain[i], domain[i + 1]);
+    r[i] = interpolate(range[i], range[i + 1]);
+  }
+
+  return function(x) {
+    var i = d3Array.bisect(domain, x, 1, j) - 1;
+    return r[i](d[i](x));
+  };
+}
+
+function copy$1(source, target) {
+  return target
+      .domain(source.domain())
+      .range(source.range())
+      .interpolate(source.interpolate())
+      .clamp(source.clamp())
+      .unknown(source.unknown());
+}
+
+function transformer$2() {
+  var domain = unit,
+      range = unit,
+      interpolate = d3Interpolate.interpolate,
+      transform,
+      untransform,
+      unknown,
+      clamp = identity$1,
+      piecewise,
+      output,
+      input;
+
+  function rescale() {
+    var n = Math.min(domain.length, range.length);
+    if (clamp !== identity$1) clamp = clamper(domain[0], domain[n - 1]);
+    piecewise = n > 2 ? polymap : bimap;
+    output = input = null;
+    return scale;
+  }
+
+  function scale(x) {
+    return x == null || isNaN(x = +x) ? unknown : (output || (output = piecewise(domain.map(transform), range, interpolate)))(transform(clamp(x)));
+  }
+
+  scale.invert = function(y) {
+    return clamp(untransform((input || (input = piecewise(range, domain.map(transform), d3Interpolate.interpolateNumber)))(y)));
+  };
+
+  scale.domain = function(_) {
+    return arguments.length ? (domain = Array.from(_, number$1), rescale()) : domain.slice();
+  };
+
+  scale.range = function(_) {
+    return arguments.length ? (range = Array.from(_), rescale()) : range.slice();
+  };
+
+  scale.rangeRound = function(_) {
+    return range = Array.from(_), interpolate = d3Interpolate.interpolateRound, rescale();
+  };
+
+  scale.clamp = function(_) {
+    return arguments.length ? (clamp = _ ? true : identity$1, rescale()) : clamp !== identity$1;
+  };
+
+  scale.interpolate = function(_) {
+    return arguments.length ? (interpolate = _, rescale()) : interpolate;
+  };
+
+  scale.unknown = function(_) {
+    return arguments.length ? (unknown = _, scale) : unknown;
+  };
+
+  return function(t, u) {
+    transform = t, untransform = u;
+    return rescale();
+  };
+}
+
+function continuous() {
+  return transformer$2()(identity$1, identity$1);
+}
+
+function tickFormat(start, stop, count, specifier) {
+  var step = d3Array.tickStep(start, stop, count),
+      precision;
+  specifier = d3Format.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 = d3Format.precisionPrefix(step, value))) specifier.precision = precision;
+      return d3Format.formatPrefix(specifier, value);
+    }
+    case "":
+    case "e":
+    case "g":
+    case "p":
+    case "r": {
+      if (specifier.precision == null && !isNaN(precision = d3Format.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 = d3Format.precisionFixed(step))) specifier.precision = precision - (specifier.type === "%") * 2;
+      break;
+    }
+  }
+  return d3Format.format(specifier);
+}
+
+function linearish(scale) {
+  var domain = scale.domain;
+
+  scale.ticks = function(count) {
+    var d = domain();
+    return d3Array.ticks(d[0], d[d.length - 1], count == null ? 10 : count);
+  };
+
+  scale.tickFormat = function(count, specifier) {
+    var d = domain();
+    return tickFormat(d[0], d[d.length - 1], count == null ? 10 : count, specifier);
+  };
+
+  scale.nice = function(count) {
+    if (count == null) count = 10;
+
+    var d = domain();
+    var i0 = 0;
+    var i1 = d.length - 1;
+    var start = d[i0];
+    var stop = d[i1];
+    var prestep;
+    var step;
+    var maxIter = 10;
+
+    if (stop < start) {
+      step = start, start = stop, stop = step;
+      step = i0, i0 = i1, i1 = step;
+    }
+    
+    while (maxIter-- > 0) {
+      step = d3Array.tickIncrement(start, stop, count);
+      if (step === prestep) {
+        d[i0] = start;
+        d[i1] = stop;
+        return domain(d);
+      } else if (step > 0) {
+        start = Math.floor(start / step) * step;
+        stop = Math.ceil(stop / step) * step;
+      } else if (step < 0) {
+        start = Math.ceil(start * step) / step;
+        stop = Math.floor(stop * step) / step;
+      } else {
+        break;
+      }
+      prestep = step;
+    }
+
+    return scale;
+  };
+
+  return scale;
+}
+
+function linear() {
+  var scale = continuous();
+
+  scale.copy = function() {
+    return copy$1(scale, linear());
+  };
+
+  initRange.apply(scale, arguments);
+
+  return linearish(scale);
+}
+
+function identity(domain) {
+  var unknown;
+
+  function scale(x) {
+    return x == null || isNaN(x = +x) ? unknown : x;
+  }
+
+  scale.invert = scale;
+
+  scale.domain = scale.range = function(_) {
+    return arguments.length ? (domain = Array.from(_, number$1), scale) : domain.slice();
+  };
+
+  scale.unknown = function(_) {
+    return arguments.length ? (unknown = _, scale) : unknown;
+  };
+
+  scale.copy = function() {
+    return identity(domain).unknown(unknown);
+  };
+
+  domain = arguments.length ? Array.from(domain, number$1) : [0, 1];
+
+  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 transformLog(x) {
+  return Math.log(x);
+}
+
+function transformExp(x) {
+  return Math.exp(x);
+}
+
+function transformLogn(x) {
+  return -Math.log(-x);
+}
+
+function transformExpn(x) {
+  return -Math.exp(-x);
+}
+
+function pow10(x) {
+  return isFinite(x) ? +("1e" + x) : x < 0 ? 0 : x;
+}
+
+function powp(base) {
+  return base === 10 ? pow10
+      : base === Math.E ? Math.exp
+      : x => 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), x => Math.log(x) / base);
+}
+
+function reflect(f) {
+  return (x, k) => -f(-x, k);
+}
+
+function loggish(transform) {
+  const scale = transform(transformLog, transformExp);
+  const domain = scale.domain;
+  let base = 10;
+  let logs;
+  let pows;
+
+  function rescale() {
+    logs = logp(base), pows = powp(base);
+    if (domain()[0] < 0) {
+      logs = reflect(logs), pows = reflect(pows);
+      transform(transformLogn, transformExpn);
+    } else {
+      transform(transformLog, transformExp);
+    }
+    return scale;
+  }
+
+  scale.base = function(_) {
+    return arguments.length ? (base = +_, rescale()) : base;
+  };
+
+  scale.domain = function(_) {
+    return arguments.length ? (domain(_), rescale()) : domain();
+  };
+
+  scale.ticks = count => {
+    const d = domain();
+    let u = d[0];
+    let v = d[d.length - 1];
+    const r = v < u;
+
+    if (r) ([u, v] = [v, u]);
+
+    let i = logs(u);
+    let j = logs(v);
+    let k;
+    let t;
+    const n = count == null ? 10 : +count;
+    let z = [];
+
+    if (!(base % 1) && j - i < n) {
+      i = Math.floor(i), j = Math.ceil(j);
+      if (u > 0) for (; i <= j; ++i) {
+        for (k = 1; k < base; ++k) {
+          t = i < 0 ? k / pows(-i) : k * pows(i);
+          if (t < u) continue;
+          if (t > v) break;
+          z.push(t);
+        }
+      } else for (; i <= j; ++i) {
+        for (k = base - 1; k >= 1; --k) {
+          t = i > 0 ? k / pows(-i) : k * pows(i);
+          if (t < u) continue;
+          if (t > v) break;
+          z.push(t);
+        }
+      }
+      if (z.length * 2 < n) z = d3Array.ticks(u, v, n);
+    } else {
+      z = d3Array.ticks(i, j, Math.min(j - i, n)).map(pows);
+    }
+    return r ? z.reverse() : z;
+  };
+
+  scale.tickFormat = (count, specifier) => {
+    if (count == null) count = 10;
+    if (specifier == null) specifier = base === 10 ? "s" : ",";
+    if (typeof specifier !== "function") {
+      if (!(base % 1) && (specifier = d3Format.formatSpecifier(specifier)).precision == null) specifier.trim = true;
+      specifier = d3Format.format(specifier);
+    }
+    if (count === Infinity) return specifier;
+    const k = Math.max(1, base * count / scale.ticks().length); // TODO fast estimate?
+    return d => {
+      let i = d / pows(Math.round(logs(d)));
+      if (i * base < base - 0.5) i *= base;
+      return i <= k ? specifier(d) : "";
+    };
+  };
+
+  scale.nice = () => {
+    return domain(nice(domain(), {
+      floor: x => pows(Math.floor(logs(x))),
+      ceil: x => pows(Math.ceil(logs(x)))
+    }));
+  };
+
+  return scale;
+}
+
+function log() {
+  const scale = loggish(transformer$2()).domain([1, 10]);
+  scale.copy = () => copy$1(scale, log()).base(scale.base());
+  initRange.apply(scale, arguments);
+  return scale;
+}
+
+function transformSymlog(c) {
+  return function(x) {
+    return Math.sign(x) * Math.log1p(Math.abs(x / c));
+  };
+}
+
+function transformSymexp(c) {
+  return function(x) {
+    return Math.sign(x) * Math.expm1(Math.abs(x)) * c;
+  };
+}
+
+function symlogish(transform) {
+  var c = 1, scale = transform(transformSymlog(c), transformSymexp(c));
+
+  scale.constant = function(_) {
+    return arguments.length ? transform(transformSymlog(c = +_), transformSymexp(c)) : c;
+  };
+
+  return linearish(scale);
+}
+
+function symlog() {
+  var scale = symlogish(transformer$2());
+
+  scale.copy = function() {
+    return copy$1(scale, symlog()).constant(scale.constant());
+  };
+
+  return initRange.apply(scale, arguments);
+}
+
+function transformPow(exponent) {
+  return function(x) {
+    return x < 0 ? -Math.pow(-x, exponent) : Math.pow(x, exponent);
+  };
+}
+
+function transformSqrt(x) {
+  return x < 0 ? -Math.sqrt(-x) : Math.sqrt(x);
+}
+
+function transformSquare(x) {
+  return x < 0 ? -x * x : x * x;
+}
+
+function powish(transform) {
+  var scale = transform(identity$1, identity$1),
+      exponent = 1;
+
+  function rescale() {
+    return exponent === 1 ? transform(identity$1, identity$1)
+        : exponent === 0.5 ? transform(transformSqrt, transformSquare)
+        : transform(transformPow(exponent), transformPow(1 / exponent));
+  }
+
+  scale.exponent = function(_) {
+    return arguments.length ? (exponent = +_, rescale()) : exponent;
+  };
+
+  return linearish(scale);
+}
+
+function pow() {
+  var scale = powish(transformer$2());
+
+  scale.copy = function() {
+    return copy$1(scale, pow()).exponent(scale.exponent());
+  };
+
+  initRange.apply(scale, arguments);
+
+  return scale;
+}
+
+function sqrt() {
+  return pow.apply(null, arguments).exponent(0.5);
+}
+
+function square(x) {
+  return Math.sign(x) * x * x;
+}
+
+function unsquare(x) {
+  return Math.sign(x) * Math.sqrt(Math.abs(x));
+}
+
+function radial() {
+  var squared = continuous(),
+      range = [0, 1],
+      round = false,
+      unknown;
+
+  function scale(x) {
+    var y = unsquare(squared(x));
+    return isNaN(y) ? unknown : round ? Math.round(y) : y;
+  }
+
+  scale.invert = function(y) {
+    return squared.invert(square(y));
+  };
+
+  scale.domain = function(_) {
+    return arguments.length ? (squared.domain(_), scale) : squared.domain();
+  };
+
+  scale.range = function(_) {
+    return arguments.length ? (squared.range((range = Array.from(_, number$1)).map(square)), scale) : range.slice();
+  };
+
+  scale.rangeRound = function(_) {
+    return scale.range(_).round(true);
+  };
+
+  scale.round = function(_) {
+    return arguments.length ? (round = !!_, scale) : round;
+  };
+
+  scale.clamp = function(_) {
+    return arguments.length ? (squared.clamp(_), scale) : squared.clamp();
+  };
+
+  scale.unknown = function(_) {
+    return arguments.length ? (unknown = _, scale) : unknown;
+  };
+
+  scale.copy = function() {
+    return radial(squared.domain(), range)
+        .round(round)
+        .clamp(squared.clamp())
+        .unknown(unknown);
+  };
+
+  initRange.apply(scale, arguments);
+
+  return linearish(scale);
+}
+
+function quantile() {
+  var domain = [],
+      range = [],
+      thresholds = [],
+      unknown;
+
+  function rescale() {
+    var i = 0, n = Math.max(1, range.length);
+    thresholds = new Array(n - 1);
+    while (++i < n) thresholds[i - 1] = d3Array.quantileSorted(domain, i / n);
+    return scale;
+  }
+
+  function scale(x) {
+    return x == null || isNaN(x = +x) ? unknown : range[d3Array.bisect(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 (let d of _) if (d != null && !isNaN(d = +d)) domain.push(d);
+    domain.sort(d3Array.ascending);
+    return rescale();
+  };
+
+  scale.range = function(_) {
+    return arguments.length ? (range = Array.from(_), rescale()) : range.slice();
+  };
+
+  scale.unknown = function(_) {
+    return arguments.length ? (unknown = _, scale) : unknown;
+  };
+
+  scale.quantiles = function() {
+    return thresholds.slice();
+  };
+
+  scale.copy = function() {
+    return quantile()
+        .domain(domain)
+        .range(range)
+        .unknown(unknown);
+  };
+
+  return initRange.apply(scale, arguments);
+}
+
+function quantize() {
+  var x0 = 0,
+      x1 = 1,
+      n = 1,
+      domain = [0.5],
+      range = [0, 1],
+      unknown;
+
+  function scale(x) {
+    return x != null && x <= x ? range[d3Array.bisect(domain, x, 0, n)] : unknown;
+  }
+
+  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, x1] = _, x0 = +x0, x1 = +x1, rescale()) : [x0, x1];
+  };
+
+  scale.range = function(_) {
+    return arguments.length ? (n = (range = Array.from(_)).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.unknown = function(_) {
+    return arguments.length ? (unknown = _, scale) : scale;
+  };
+
+  scale.thresholds = function() {
+    return domain.slice();
+  };
+
+  scale.copy = function() {
+    return quantize()
+        .domain([x0, x1])
+        .range(range)
+        .unknown(unknown);
+  };
+
+  return initRange.apply(linearish(scale), arguments);
+}
+
+function threshold() {
+  var domain = [0.5],
+      range = [0, 1],
+      unknown,
+      n = 1;
+
+  function scale(x) {
+    return x != null && x <= x ? range[d3Array.bisect(domain, x, 0, n)] : unknown;
+  }
+
+  scale.domain = function(_) {
+    return arguments.length ? (domain = Array.from(_), n = Math.min(domain.length, range.length - 1), scale) : domain.slice();
+  };
+
+  scale.range = function(_) {
+    return arguments.length ? (range = Array.from(_), 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.unknown = function(_) {
+    return arguments.length ? (unknown = _, scale) : unknown;
+  };
+
+  scale.copy = function() {
+    return threshold()
+        .domain(domain)
+        .range(range)
+        .unknown(unknown);
+  };
+
+  return initRange.apply(scale, arguments);
+}
+
+function date(t) {
+  return new Date(t);
+}
+
+function number(t) {
+  return t instanceof Date ? +t : +new Date(+t);
+}
+
+function calendar(ticks, tickInterval, year, month, week, day, hour, minute, second, format) {
+  var scale = continuous(),
+      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");
+
+  function tickFormat(date) {
+    return (second(date) < date ? formatMillisecond
+        : minute(date) < date ? formatSecond
+        : hour(date) < date ? formatMinute
+        : day(date) < date ? formatHour
+        : month(date) < date ? (week(date) < date ? formatDay : formatWeek)
+        : year(date) < date ? formatMonth
+        : formatYear)(date);
+  }
+
+  scale.invert = function(y) {
+    return new Date(invert(y));
+  };
+
+  scale.domain = function(_) {
+    return arguments.length ? domain(Array.from(_, number)) : domain().map(date);
+  };
+
+  scale.ticks = function(interval) {
+    var d = domain();
+    return ticks(d[0], d[d.length - 1], interval == null ? 10 : interval);
+  };
+
+  scale.tickFormat = function(count, specifier) {
+    return specifier == null ? tickFormat : format(specifier);
+  };
+
+  scale.nice = function(interval) {
+    var d = domain();
+    if (!interval || typeof interval.range !== "function") interval = tickInterval(d[0], d[d.length - 1], interval == null ? 10 : interval);
+    return interval ? domain(nice(d, interval)) : scale;
+  };
+
+  scale.copy = function() {
+    return copy$1(scale, calendar(ticks, tickInterval, year, month, week, day, hour, minute, second, format));
+  };
+
+  return scale;
+}
+
+function time() {
+  return initRange.apply(calendar(d3Time.timeTicks, d3Time.timeTickInterval, d3Time.timeYear, d3Time.timeMonth, d3Time.timeWeek, d3Time.timeDay, d3Time.timeHour, d3Time.timeMinute, d3Time.timeSecond, d3TimeFormat.timeFormat).domain([new Date(2000, 0, 1), new Date(2000, 0, 2)]), arguments);
+}
+
+function utcTime() {
+  return initRange.apply(calendar(d3Time.utcTicks, d3Time.utcTickInterval, d3Time.utcYear, d3Time.utcMonth, d3Time.utcWeek, d3Time.utcDay, d3Time.utcHour, d3Time.utcMinute, d3Time.utcSecond, d3TimeFormat.utcFormat).domain([Date.UTC(2000, 0, 1), Date.UTC(2000, 0, 2)]), arguments);
+}
+
+function transformer$1() {
+  var x0 = 0,
+      x1 = 1,
+      t0,
+      t1,
+      k10,
+      transform,
+      interpolator = identity$1,
+      clamp = false,
+      unknown;
+
+  function scale(x) {
+    return x == null || isNaN(x = +x) ? unknown : interpolator(k10 === 0 ? 0.5 : (x = (transform(x) - t0) * k10, clamp ? Math.max(0, Math.min(1, x)) : x));
+  }
+
+  scale.domain = function(_) {
+    return arguments.length ? ([x0, x1] = _, t0 = transform(x0 = +x0), t1 = transform(x1 = +x1), k10 = t0 === t1 ? 0 : 1 / (t1 - t0), scale) : [x0, x1];
+  };
+
+  scale.clamp = function(_) {
+    return arguments.length ? (clamp = !!_, scale) : clamp;
+  };
+
+  scale.interpolator = function(_) {
+    return arguments.length ? (interpolator = _, scale) : interpolator;
+  };
+
+  function range(interpolate) {
+    return function(_) {
+      var r0, r1;
+      return arguments.length ? ([r0, r1] = _, interpolator = interpolate(r0, r1), scale) : [interpolator(0), interpolator(1)];
+    };
+  }
+
+  scale.range = range(d3Interpolate.interpolate);
+
+  scale.rangeRound = range(d3Interpolate.interpolateRound);
+
+  scale.unknown = function(_) {
+    return arguments.length ? (unknown = _, scale) : unknown;
+  };
+
+  return function(t) {
+    transform = t, t0 = t(x0), t1 = t(x1), k10 = t0 === t1 ? 0 : 1 / (t1 - t0);
+    return scale;
+  };
+}
+
+function copy(source, target) {
+  return target
+      .domain(source.domain())
+      .interpolator(source.interpolator())
+      .clamp(source.clamp())
+      .unknown(source.unknown());
+}
+
+function sequential() {
+  var scale = linearish(transformer$1()(identity$1));
+
+  scale.copy = function() {
+    return copy(scale, sequential());
+  };
+
+  return initInterpolator.apply(scale, arguments);
+}
+
+function sequentialLog() {
+  var scale = loggish(transformer$1()).domain([1, 10]);
+
+  scale.copy = function() {
+    return copy(scale, sequentialLog()).base(scale.base());
+  };
+
+  return initInterpolator.apply(scale, arguments);
+}
+
+function sequentialSymlog() {
+  var scale = symlogish(transformer$1());
+
+  scale.copy = function() {
+    return copy(scale, sequentialSymlog()).constant(scale.constant());
+  };
+
+  return initInterpolator.apply(scale, arguments);
+}
+
+function sequentialPow() {
+  var scale = powish(transformer$1());
+
+  scale.copy = function() {
+    return copy(scale, sequentialPow()).exponent(scale.exponent());
+  };
+
+  return initInterpolator.apply(scale, arguments);
+}
+
+function sequentialSqrt() {
+  return sequentialPow.apply(null, arguments).exponent(0.5);
+}
+
+function sequentialQuantile() {
+  var domain = [],
+      interpolator = identity$1;
+
+  function scale(x) {
+    if (x != null && !isNaN(x = +x)) return interpolator((d3Array.bisect(domain, x, 1) - 1) / (domain.length - 1));
+  }
+
+  scale.domain = function(_) {
+    if (!arguments.length) return domain.slice();
+    domain = [];
+    for (let d of _) if (d != null && !isNaN(d = +d)) domain.push(d);
+    domain.sort(d3Array.ascending);
+    return scale;
+  };
+
+  scale.interpolator = function(_) {
+    return arguments.length ? (interpolator = _, scale) : interpolator;
+  };
+
+  scale.range = function() {
+    return domain.map((d, i) => interpolator(i / (domain.length - 1)));
+  };
+
+  scale.quantiles = function(n) {
+    return Array.from({length: n + 1}, (_, i) => d3Array.quantile(domain, i / n));
+  };
+
+  scale.copy = function() {
+    return sequentialQuantile(interpolator).domain(domain);
+  };
+
+  return initInterpolator.apply(scale, arguments);
+}
+
+function transformer() {
+  var x0 = 0,
+      x1 = 0.5,
+      x2 = 1,
+      s = 1,
+      t0,
+      t1,
+      t2,
+      k10,
+      k21,
+      interpolator = identity$1,
+      transform,
+      clamp = false,
+      unknown;
+
+  function scale(x) {
+    return isNaN(x = +x) ? unknown : (x = 0.5 + ((x = +transform(x)) - t1) * (s * x < s * t1 ? k10 : k21), interpolator(clamp ? Math.max(0, Math.min(1, x)) : x));
+  }
+
+  scale.domain = function(_) {
+    return arguments.length ? ([x0, x1, x2] = _, t0 = transform(x0 = +x0), t1 = transform(x1 = +x1), t2 = transform(x2 = +x2), k10 = t0 === t1 ? 0 : 0.5 / (t1 - t0), k21 = t1 === t2 ? 0 : 0.5 / (t2 - t1), s = t1 < t0 ? -1 : 1, scale) : [x0, x1, x2];
+  };
+
+  scale.clamp = function(_) {
+    return arguments.length ? (clamp = !!_, scale) : clamp;
+  };
+
+  scale.interpolator = function(_) {
+    return arguments.length ? (interpolator = _, scale) : interpolator;
+  };
+
+  function range(interpolate) {
+    return function(_) {
+      var r0, r1, r2;
+      return arguments.length ? ([r0, r1, r2] = _, interpolator = d3Interpolate.piecewise(interpolate, [r0, r1, r2]), scale) : [interpolator(0), interpolator(0.5), interpolator(1)];
+    };
+  }
+
+  scale.range = range(d3Interpolate.interpolate);
+
+  scale.rangeRound = range(d3Interpolate.interpolateRound);
+
+  scale.unknown = function(_) {
+    return arguments.length ? (unknown = _, scale) : unknown;
+  };
+
+  return function(t) {
+    transform = t, t0 = t(x0), t1 = t(x1), t2 = t(x2), k10 = t0 === t1 ? 0 : 0.5 / (t1 - t0), k21 = t1 === t2 ? 0 : 0.5 / (t2 - t1), s = t1 < t0 ? -1 : 1;
+    return scale;
+  };
+}
+
+function diverging() {
+  var scale = linearish(transformer()(identity$1));
+
+  scale.copy = function() {
+    return copy(scale, diverging());
+  };
+
+  return initInterpolator.apply(scale, arguments);
+}
+
+function divergingLog() {
+  var scale = loggish(transformer()).domain([0.1, 1, 10]);
+
+  scale.copy = function() {
+    return copy(scale, divergingLog()).base(scale.base());
+  };
+
+  return initInterpolator.apply(scale, arguments);
+}
+
+function divergingSymlog() {
+  var scale = symlogish(transformer());
+
+  scale.copy = function() {
+    return copy(scale, divergingSymlog()).constant(scale.constant());
+  };
+
+  return initInterpolator.apply(scale, arguments);
+}
+
+function divergingPow() {
+  var scale = powish(transformer());
+
+  scale.copy = function() {
+    return copy(scale, divergingPow()).exponent(scale.exponent());
+  };
+
+  return initInterpolator.apply(scale, arguments);
+}
+
+function divergingSqrt() {
+  return divergingPow.apply(null, arguments).exponent(0.5);
+}
+
+exports.scaleBand = band;
+exports.scaleDiverging = diverging;
+exports.scaleDivergingLog = divergingLog;
+exports.scaleDivergingPow = divergingPow;
+exports.scaleDivergingSqrt = divergingSqrt;
+exports.scaleDivergingSymlog = divergingSymlog;
+exports.scaleIdentity = identity;
+exports.scaleImplicit = implicit;
+exports.scaleLinear = linear;
+exports.scaleLog = log;
+exports.scaleOrdinal = ordinal;
+exports.scalePoint = point;
+exports.scalePow = pow;
+exports.scaleQuantile = quantile;
+exports.scaleQuantize = quantize;
+exports.scaleRadial = radial;
+exports.scaleSequential = sequential;
+exports.scaleSequentialLog = sequentialLog;
+exports.scaleSequentialPow = sequentialPow;
+exports.scaleSequentialQuantile = sequentialQuantile;
+exports.scaleSequentialSqrt = sequentialSqrt;
+exports.scaleSequentialSymlog = sequentialSymlog;
+exports.scaleSqrt = sqrt;
+exports.scaleSymlog = symlog;
+exports.scaleThreshold = threshold;
+exports.scaleTime = time;
+exports.scaleUtc = utcTime;
+exports.tickFormat = tickFormat;
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+}));