src/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 /*global Dygraph:false */
  13 "use strict";
  14
  15 import BarsHandler from './bars';
  16
  17 /**
  18  * @constructor
  19  * @extends Dygraph.DataHandlers.BarsHandler
  20  */
  21 var CustomBarsHandler = function() {
  22 };
  23
  24 CustomBarsHandler.prototype = new BarsHandler();
  25
  26 /** @inheritDoc */
  27 CustomBarsHandler.prototype.extractSeries = function(rawData, i, options) {
  28   // TODO(danvk): pre-allocate series here.
  29   var series = [];
  30   var x, y, point;
  31   var logScale = options.get('logscale');
  32   for ( var j = 0; j < rawData.length; j++) {
  33     x = rawData[j][0];
  34     point = rawData[j][i];
  35     if (logScale && point !== null) {
  36       // On the log scale, points less than zero do not exist.
  37       // This will create a gap in the chart.
  38       if (point[0] <= 0 || point[1] <= 0 || point[2] <= 0) {
  39         point = null;
  40       }
  41     }
  42     // Extract to the unified data format.
  43     if (point !== null) {
  44       y = point[1];
  45       if (y !== null && !isNaN(y)) {
  46         series.push([ x, y, [ point[0], point[2] ] ]);
  47       } else {
  48         series.push([ x, y, [ y, y ] ]);
  49       }
  50     } else {
  51       series.push([ x, null, [ null, null ] ]);
  52     }
  53   }
  54   return series;
  55 };
  56
  57 /** @inheritDoc */
  58 CustomBarsHandler.prototype.rollingAverage =
  59     function(originalData, rollPeriod, options) {
  60   rollPeriod = Math.min(rollPeriod, originalData.length);
  61   var rollingData = [];
  62   var y, low, high, mid,count, i, extremes;
  63
  64   low = 0;
  65   mid = 0;
  66   high = 0;
  67   count = 0;
  68   for (i = 0; i < originalData.length; i++) {
  69     y = originalData[i][1];
  70     extremes = originalData[i][2];
  71     rollingData[i] = originalData[i];
  72
  73     if (y !== null && !isNaN(y)) {
  74       low += extremes[0];
  75       mid += y;
  76       high += extremes[1];
  77       count += 1;
  78     }
  79     if (i - rollPeriod >= 0) {
  80       var prev = originalData[i - rollPeriod];
  81       if (prev[1] !== null && !isNaN(prev[1])) {
  82         low -= prev[2][0];
  83         mid -= prev[1];
  84         high -= prev[2][1];
  85         count -= 1;
  86       }
  87     }
  88     if (count) {
  89       rollingData[i] = [
  90           originalData[i][0],
  91           1.0 * mid / count,
  92           [ 1.0 * low / count,
  93             1.0 * high / count ] ];
  94     } else {
  95       rollingData[i] = [ originalData[i][0], null, [ null, null ] ];
  96     }
  97   }
  98
  99   return rollingData;
 100 };
 101
 102 export default CustomBarsHandler;