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
  14 /*global Dygraph:false */
  15 "use strict";
  16
  17 Dygraph.DataHandlers.CustomBarsHandler = Dygraph.DataHandler();
  18 var CustomBarsHandler = Dygraph.DataHandlers.CustomBarsHandler;
  19 CustomBarsHandler.prototype = new Dygraph.DataHandlers.BarsHandler();
  20
  21 // customBars
  22 CustomBarsHandler.prototype.extractSeries = function(rawData, i, options) {
  23   // TODO(danvk): pre-allocate series here.
  24   var series = [];
  25   var x, y, point;
  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 || point[2] <= 0) {
  34         point = null;
  35       }
  36     }
  37     // Extract to the unified data format.
  38     if (point !== null) {
  39       y = point[1];
  40       if (y !== null && !isNaN(y)) {
  41         series.push([ x, y, [ point[0], point[2] ] ]);
  42       } else {
  43         series.push([ x, y, [ y, y ] ]);
  44       }
  45     } else {
  46       series.push([ x, null, [ null, null ] ]);
  47     }
  48   }
  49   return series;
  50 };
  51
  52 CustomBarsHandler.prototype.rollingAverage = function(originalData, rollPeriod,
  53     options) {
  54   rollPeriod = Math.min(rollPeriod, originalData.length);
  55   var rollingData = [];
  56   var y, low, high, mid,count, i, extremes;
  57
  58   low = 0;
  59   mid = 0;
  60   high = 0;
  61   count = 0;
  62   for (i = 0; i < originalData.length; i++) {
  63     y = originalData[i][1];
  64     extremes = originalData[i][2];
  65     rollingData[i] = originalData[i];
  66
  67     if (y !== null && !isNaN(y)) {
  68       low += extremes[0];
  69       mid += y;
  70       high += extremes[1];
  71       count += 1;
  72     }
  73     if (i - rollPeriod >= 0) {
  74       var prev = originalData[i - rollPeriod];
  75       if (prev[1] !== null && !isNaN(prev[1])) {
  76         low -= prev[2][0];
  77         mid -= prev[1];
  78         high -= prev[2][1];
  79         count -= 1;
  80       }
  81     }
  82     if (count) {
  83       rollingData[i] = [
  84           originalData[i][0],
  85           1.0 * mid / count,
  86           [ 1.0 * low / count,
  87             1.0 * high / count ] ];
  88     } else {
  89       rollingData[i] = [ originalData[i][0], null, [ null, null ] ];
  90     }
  91   }
  92
  93   return rollingData;
  94 };
  95
  96 })();