7e234b07dadedea7714015bca99f6b3d4bb34e42
[dygraphs.git] / 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 /*global Dygraph:false */
14 "use strict";
15
16 var DefaultFractionHandler = Dygraph.DataHandler();
17 DefaultFractionHandler.prototype = Dygraph.DataHandlers.createHandler("default");
18 Dygraph.DataHandlers.registerHandler("default-fractions", DefaultFractionHandler);
19
20 DefaultFractionHandler.prototype.extractSeries = function(rawData, i, options) {
21 // TODO(danvk): pre-allocate series here.
22 var series = [];
23 var x, y, point, num, den, value;
24 var mult = 100.0;
25 var logScale = options.get('logscale');
26 for ( var j = 0; j < rawData.length; j++) {
27 x = rawData[j][0];
28 point = rawData[j][i];
29 if (logScale && point !== null) {
30 // On the log scale, points less than zero do not exist.
31 // This will create a gap in the chart.
32 if (point[0] <= 0 || point[1] <= 0) {
33 point = null;
34 }
35 }
36 // Extract to the unified data format.
37 if (point !== null) {
38 num = point[0];
39 den = point[1];
40 if (num !== null && !isNaN(num)) {
41 value = den ? num / den : 0.0;
42 y = mult * value;
43 // preserve original values in extras for further filtering
44 series.push([ x, y, [ num, den ] ]);
45 } else {
46 series.push([ x, num, [ num, den ] ]);
47 }
48 } else {
49 series.push([ x, null, [ null, null ] ]);
50 }
51 }
52 return series;
53 };
54
55 DefaultFractionHandler.prototype.rollingAverage = function(originalData, rollPeriod,
56 options) {
57 rollPeriod = Math.min(rollPeriod, originalData.length);
58 var rollingData = [];
59
60 var i;
61 var num = 0;
62 var den = 0; // numerator/denominator
63 var mult = 100.0;
64 for (i = 0; i < originalData.length; i++) {
65 num += originalData[i][2][0];
66 den += originalData[i][2][1];
67 if (i - rollPeriod >= 0) {
68 num -= originalData[i - rollPeriod][2][0];
69 den -= originalData[i - rollPeriod][2][1];
70 }
71
72 var date = originalData[i][0];
73 var value = den ? num / den : 0.0;
74 rollingData[i] = [ date, mult * value ];
75 }
76
77 return rollingData;
78 };
79 })();