datahandler/default-fractions.js

   1 /**
   2  * @license
   3  * Copyright 2013 David Eberlein (david.eberlein@ch.sauter-bc.com)
   4  * MIT-licensed (http://opensource.org/licenses/MIT)
   5  */
   6
   7 /**
   8  * @fileoverview DataHandler implementation for the fractions option.
   9  * @author David Eberlein (david.eberlein@ch.sauter-bc.com)
  10  */
  11
  12 (function() {
  13
  14 /*global Dygraph:false */
  15 "use strict";
  16
  17 Dygraph.DataHandlers.DefaultFractionHandler = Dygraph.DataHandler();
  18 var DefaultFractionHandler = Dygraph.DataHandlers.DefaultFractionHandler;
  19 DefaultFractionHandler.prototype = new Dygraph.DataHandlers.DefaultHandler();
  20
  21 DefaultFractionHandler.prototype.extractSeries = function(rawData, i, options) {
  22   // TODO(danvk): pre-allocate series here.
  23   var series = [];
  24   var x, y, point, num, den, value;
  25   var mult = 100.0;
  26   var logScale = options.get('logscale');
  27   for ( var j = 0; j < rawData.length; j++) {
  28     x = rawData[j][0];
  29     point = rawData[j][i];
  30     if (logScale && point !== null) {
  31       // On the log scale, points less than zero do not exist.
  32       // This will create a gap in the chart.
  33       if (point[0] <= 0 || point[1] <= 0) {
  34         point = null;
  35       }
  36     }
  37     // Extract to the unified data format.
  38     if (point !== null) {
  39       num = point[0];
  40       den = point[1];
  41       if (num !== null && !isNaN(num)) {
  42         value = den ? num / den : 0.0;
  43         y = mult * value;
  44         // preserve original values in extras for further filtering
  45         series.push([ x, y, [ num, den ] ]);
  46       } else {
  47         series.push([ x, num, [ num, den ] ]);
  48       }
  49     } else {
  50       series.push([ x, null, [ null, null ] ]);
  51     }
  52   }
  53   return series;
  54 };
  55
  56 DefaultFractionHandler.prototype.rollingAverage = function(originalData, rollPeriod,
  57     options) {
  58   rollPeriod = Math.min(rollPeriod, originalData.length);
  59   var rollingData = [];
  60
  61   var i;
  62   var num = 0;
  63   var den = 0; // numerator/denominator
  64   var mult = 100.0;
  65   for (i = 0; i < originalData.length; i++) {
  66     num += originalData[i][2][0];
  67     den += originalData[i][2][1];
  68     if (i - rollPeriod >= 0) {
  69       num -= originalData[i - rollPeriod][2][0];
  70       den -= originalData[i - rollPeriod][2][1];
  71     }
  72
  73     var date = originalData[i][0];
  74     var value = den ? num / den : 0.0;
  75     rollingData[i] = [ date, mult * value ];
  76   }
  77
  78   return rollingData;
  79 };
  80
  81 })();