datahandler/bars-custom.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 custom bars option.
   9  * @author David Eberlein (david.eberlein@ch.sauter-bc.com)
  10  */
  11
  12 (function() {
  13   /*global Dygraph:false */
  14   "use strict";
  15
  16   var CustomBarsHandler = Dygraph.DataHandler();
  17   CustomBarsHandler.prototype = Dygraph.DataHandlers.createHandler("bars");
  18   Dygraph.DataHandlers.registerHandler("bars-custom", CustomBarsHandler);
  19   // customBars
  20   CustomBarsHandler.prototype.extractSeries = function(rawData, i, options) {
  21     // TODO(danvk): pre-allocate series here.
  22     var series = [];
  23     var x, y, point;
  24     var logScale = options.get('logscale');
  25     for ( var j = 0; j < rawData.length; j++) {
  26       x = rawData[j][0];
  27       point = rawData[j][i];
  28       if (logScale && point !== null) {
  29         // On the log scale, points less than zero do not exist.
  30         // This will create a gap in the chart.
  31         if (point[0] <= 0 || point[1] <= 0 || point[2] <= 0) {
  32           point = null;
  33         }
  34       }
  35       // Extract to the unified data format.
  36       if (point !== null) {
  37         y = point[1];
  38         if (y !== null && !isNaN(y)) {
  39           series.push([ x, y, [ point[0], point[2] ] ]);
  40         } else {
  41           series.push([ x, y, [ y, y ] ]);
  42         }
  43       } else {
  44         series.push([ x, null, [ null, null ] ]);
  45       }
  46     }
  47     return series;
  48   };
  49
  50   CustomBarsHandler.prototype.rollingAverage = function(originalData, rollPeriod,
  51       options) {
  52     rollPeriod = Math.min(rollPeriod, originalData.length);
  53     var rollingData = [];
  54     var y, low, high, mid,count, i, extremes;
  55
  56     low = 0;
  57     mid = 0;
  58     high = 0;
  59     count = 0;
  60     for (i = 0; i < originalData.length; i++) {
  61       y = originalData[i][1];
  62       extremes = originalData[i][2];
  63       rollingData[i] = originalData[i];
  64
  65       if (y !== null && !isNaN(y)) {
  66         low += extremes[0];
  67         mid += y;
  68         high += extremes[1];
  69         count += 1;
  70       }
  71       if (i - rollPeriod >= 0) {
  72         var prev = originalData[i - rollPeriod];
  73         if (prev[1] !== null && !isNaN(prev[1])) {
  74           low -= prev[2][0];
  75           mid -= prev[1];
  76           high -= prev[2][1];
  77           count -= 1;
  78         }
  79       }
  80       if (count) {
  81         rollingData[i] = [
  82             originalData[i][0],
  83             1.0 * mid / count,
  84             [ 1.0 * low / count,
  85               1.0 * high / count ] ];
  86       } else {
  87         rollingData[i] = [ originalData[i][0], null, [ null, null ] ];
  88       }
  89     }
  90
  91     return rollingData;
  92   };
  93 })();