histogramjs/histogram.js

Simple histogram sorting

(function(w, d){

    'use strict';
    

    var histogram = function(opts) {
      var 
        data = opts.data,
        bins_temp = opts.bins,
        i = bins_temp.length;

      var bisector = function(f) {
        return {
          left: function(a, x, lo, hi) {
            if (arguments.length < 3) lo = 0;
            if (arguments.length < 4) hi = a.length;
            while (lo < hi) {
              var mid = lo + hi >>> 1;
              if (f.call(a, a[mid], mid) < x) lo = mid + 1;
              else hi = mid;
            }
            return lo;
          },
          right: function(a, x, lo, hi) {
            if (arguments.length < 3) lo = 0;
            if (arguments.length < 4) hi = a.length;
            while (lo < hi) {
              var mid = lo + hi >>> 1;
              if (x < f.call(a, a[mid], mid)) hi = mid;
              else lo = mid + 1;
            }
            return lo;
          }
        };
      };

      var hist_bisector = bisector(function(d) { return d; });
      var bisectLeft = hist_bisector.left;
      var bisectRight = hist_bisector.right;
      var bisect = bisectRight;

      var minimum = function(array, f) {
        var i = -1,
            n = array.length,
            a,
            b;
        if (arguments.length === 1) {
          while (++i < n && !((a = array[i]) != null && a <= a)) a = undefined;
          while (++i < n) if ((b = array[i]) != null && a > b) a = b;
        } else {
          while (++i < n && !((a = f.call(array, array[i], i)) != null && a <= a)) a = undefined;
          while (++i < n) if ((b = f.call(array, array[i], i)) != null && a > b) a = b;
        }
        return a;
      };

      var maximum = function(array, f) {
        var i = -1,
            n = array.length,
            a,
            b;
        if (arguments.length === 1) {
          while (++i < n && !((a = array[i]) != null && a <= a)) a = undefined;
          while (++i < n) if ((b = array[i]) != null && b > a) a = b;
        } else {
          while (++i < n && !((a = f.call(array, array[i], i)) != null && a <= a)) a = undefined;
          while (++i < n) if ((b = f.call(array, array[i], i)) != null && b > a) a = b;
        }
        return a;
      };

      function value(x) {
        if (!arguments.length) return valuer;
        valuer = x;
        return histogram;
      };

      function range(x) {
        if (!arguments.length) return ranger;
        ranger = hist_functor(x);
        return histogram;
      };

      function hist_functor(v) {
        return typeof v === "function" ? v : function() { return v; };
      };

      function bins(x) {
        if (!arguments.length) return binner;
        binner = typeof x === "number"
            ? function(range) { return hist_layout_histogramBinFixed(range, x); }
            : hist_functor(x);
        return histogram;
      };

      function frequency(x) {
        if (!arguments.length) return frequency;
        frequency = !!x;
        return histogram;
      };

      function hist_layout_histogramBinSturges(range, values) {
        return hist_layout_histogramBinFixed(range, Math.ceil(Math.log(values.length) / Math.LN2 + 1));
      }

      function hist_layout_histogramBinFixed(range, n) {
        var x = -1,
            b = +range[0],
            m = (range[1] - b) / n,
            f = [];
        while (++x <= n) f[x] = m * x + b;
        return f;
      }

      function hist_layout_histogramRange(values) {
        return [minimum(values), maximum(values)];
      }

      var frequency = true,
        valuer = Number,
        ranger = hist_layout_histogramRange,
        binner = hist_layout_histogramBinSturges;

      bins(bins_temp)

      var bins = [],
        values = data.map(valuer, this),
        range = ranger.call(this, values, i),
        thresholds = binner.call(this, range, values, i),
        bin,
        i = -1,
        n = values.length,
        m = thresholds.length - 1,
        k = frequency ? 1 : 1 / n,
        x;

      while (++i < m) {
        bin = bins[i] = [];
        bin.dx = thresholds[i + 1] - (bin.x = thresholds[i]);
        bin.y = 0;
      }

      if (m > 0) {
        i = -1; while(++i < n) {
          x = values[i];
          if (x >= range[0] && x <= range[1]) {
            bin = bins[bisect(thresholds, x, 1, m) - 1];
            bin.y += k;
            bin.push(data[i]);
          }
        }
      }

      return bins;
    }


    // Exports and modularity
    if (typeof module !== 'undefined' && module.exports) {
        module.exports = histogram;
    }

    if (typeof ender === 'undefined') {
        this.histogram = histogram;
    }

    if (typeof define === "function" && define.amd) {
        define('histogram', [], function () { 
            return histogram; 
        });
    }

}).call(this);