sg-heatmap/dist/es/helpers/color.js

Open-source all-in-one Swiss Army knife tool for creating Choropleth maps

var _slicedToArray = function () { function sliceIterator(arr, i) { var _arr = []; var _n = true; var _d = false; var _e = undefined; try { for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"]) _i["return"](); } finally { if (_d) throw _e; } } return _arr; } return function (arr, i) { if (Array.isArray(arr)) { return arr; } else if (Symbol.iterator in Object(arr)) { return sliceIterator(arr, i); } else { throw new TypeError("Invalid attempt to destructure non-iterable instance"); } }; }();

import chroma from 'chroma-js';

export default function getColorScale(colorArray) {
  var options = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {};

  Object.assign({
    bezierInterpolate: false,
    correctLightness: true,
    interpolationMode: 'lab'
  }, options);
  var scale = options.bezierInterpolate ? chroma.bezier(colorArray).scale() : chroma.scale(colorArray).mode(options.interpolationMode);
  if (options.correctLightness) scale = scale.correctLightness();
  return function (value) {
    return scale(value).css();
  };
}

export function optimizePointSpread(stat, options) {
  options = Object.assign({
    epsilon: 0.000001,
    gamma: 0.3,
    maxIteration: 300
  }, options);

  var values = stat.values,
      min = stat.min,
      max = stat.max;

  var domain = options.domain || [min, max];
  var v = Object.keys(values).map(function (key) {
    return (values[key] - domain[0]) / (domain[1] - domain[0]);
  });
  v.sort(function (a, b) {
    return a - b;
  });

  var k = 1;
  var kHistory = [];
  var scoreHistory = [];

  var _loop = function _loop() {
    var vk = v.map(function (item) {
      return Math.pow(item, k);
    });
    var lnV = v.map(function (item) {
      return item ? Math.log(item) : 0;
    });
    var deltaVk = [];
    var deltalnVvk = [];
    for (var i = 1; i < v.length; i++) {
      deltaVk.push(vk[i] - vk[i - 1]);
      deltalnVvk.push(lnV[i] * vk[i] - lnV[i - 1] * vk[i - 1]);
    }

    var beta = deltaVk.reduce(function (sum, dVk, i) {
      return sum + 2 * dVk * deltalnVvk[i];
    }, 0);

    var score = deltaVk.reduce(function (sum, dVn) {
      return sum + Math.pow(dVn, 2);
    }, 0);

    kHistory.push(k);
    scoreHistory.push(score);
    k = Math.exp(Math.log(k) - options.gamma * beta * k);

    if (scoreHistory.length >= 2) {
      var _scoreHistory$slice = scoreHistory.slice(-2),
          _scoreHistory$slice2 = _slicedToArray(_scoreHistory$slice, 2),
          prevScore = _scoreHistory$slice2[0],
          lastScore = _scoreHistory$slice2[1];

      if (Math.abs(lastScore - prevScore) < options.epsilon) return 'break';
    }
  };

  while (kHistory.length < options.maxIteration) {
    var _ret = _loop();

    if (_ret === 'break') break;
  }

  return { domain: domain, transform: k, kHistory: kHistory, scoreHistory: scoreHistory };
}

export function BuGn() {
  return getColorScale('BuGn', { correctLightness: false });
}

export function BuPu() {
  return getColorScale('BuPu', { correctLightness: false });
}

export function GnBu() {
  return getColorScale('GnBu', { correctLightness: false });
}

export function OrRd() {
  return getColorScale('OrRd', { correctLightness: false });
}

export function PuBu() {
  return getColorScale('PuBu', { correctLightness: false });
}

export function PuBuGn() {
  return getColorScale('PuBuGn', { correctLightness: false });
}

export function PuRd() {
  return getColorScale('PuRd', { correctLightness: false });
}

export function RdPu() {
  return getColorScale('RdPu', { correctLightness: false });
}

export function YlGn() {
  return getColorScale('YlGn', { correctLightness: false });
}

export function YlGnBu() {
  return getColorScale('YlGnBu', { correctLightness: false });
}

export function YlOrBr() {
  return getColorScale('YlOrBr', { correctLightness: false });
}

export function YlOrRd() {
  return getColorScale('YlOrRd', { correctLightness: false });
}

export function Blues() {
  return getColorScale('Blues', { correctLightness: false });
}

export function Greens() {
  return getColorScale('Greens', { correctLightness: false });
}

export function Greys() {
  return getColorScale('Greys', { correctLightness: false });
}

export function Oranges() {
  return getColorScale('Oranges', { correctLightness: false });
}

export function Purples() {
  return getColorScale('Purples', { correctLightness: false });
}

export function Reds() {
  return getColorScale('Reds', { correctLightness: false });
}

export function BrBG() {
  return getColorScale('BrBG', { correctLightness: false });
}

export function PiYG() {
  return getColorScale('PiYG', { correctLightness: false });
}

export function PRGn() {
  return getColorScale('PRGn', { correctLightness: false });
}

export function PuOr() {
  return getColorScale('PuOr', { correctLightness: false });
}

export function RdBu() {
  return getColorScale('RdBu', { correctLightness: false });
}

export function RdGy() {
  return getColorScale('RdGy', { correctLightness: false });
}

export function RdYlBu() {
  return getColorScale('RdYlBu', { correctLightness: false });
}

export function RdYlGn() {
  return getColorScale('RdYlGn', { correctLightness: false });
}

export function Spectral() {
  return getColorScale('Spectral', { correctLightness: false });
}