src/datahandler/bars.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 base implementation for the "bar"
   9  * data formats. This implementation must be extended and the
  10  * extractSeries and rollingAverage must be implemented.
  11  * @author David Eberlein (david.eberlein@ch.sauter-bc.com)
  12  */
  13
  14 (function() {
  15
  16 /*global Dygraph:false */
  17 /*global DygraphLayout:false */
  18 "use strict";
  19
  20 /**
  21  * @constructor
  22  * @extends {Dygraph.DataHandler}
  23  */
  24 Dygraph.DataHandlers.BarsHandler = function() {
  25   Dygraph.DataHandler.call(this);
  26 };
  27 Dygraph.DataHandlers.BarsHandler.prototype = new Dygraph.DataHandler();
  28
  29 // alias for the rest of the implementation
  30 var BarsHandler = Dygraph.DataHandlers.BarsHandler;
  31
  32 // TODO(danvk): figure out why the jsdoc has to be copy/pasted from superclass.
  33 //   (I get closure compiler errors if this isn't here.)
  34 /**
  35  * @override
  36  * @param {!Array.<Array>} rawData The raw data passed into dygraphs where
  37  *     rawData[i] = [x,ySeries1,...,ySeriesN].
  38  * @param {!number} seriesIndex Index of the series to extract. All other
  39  *     series should be ignored.
  40  * @param {!DygraphOptions} options Dygraph options.
  41  * @return {Array.<[!number,?number,?]>} The series in the unified data format
  42  *     where series[i] = [x,y,{extras}].
  43  */
  44 BarsHandler.prototype.extractSeries = function(rawData, seriesIndex, options) {
  45   // Not implemented here must be extended
  46 };
  47
  48 /**
  49  * @override
  50  * @param {!Array.<[!number,?number,?]>} series The series in the unified
  51  *          data format where series[i] = [x,y,{extras}].
  52  * @param {!number} rollPeriod The number of points over which to average the data
  53  * @param {!DygraphOptions} options The dygraph options.
  54  * TODO(danvk): be more specific than "Array" here.
  55  * @return {!Array.<[!number,?number,?]>} the rolled series.
  56  */
  57 BarsHandler.prototype.rollingAverage =
  58     function(series, rollPeriod, options) {
  59   // Not implemented here, must be extended.
  60 };
  61
  62 /** @inheritDoc */
  63 BarsHandler.prototype.onPointsCreated_ = function(series, points) {
  64   for (var i = 0; i < series.length; ++i) {
  65     var item = series[i];
  66     var point = points[i];
  67     point.y_top = NaN;
  68     point.y_bottom = NaN;
  69     point.yval_minus = Dygraph.DataHandler.parseFloat(item[2][0]);
  70     point.yval_plus = Dygraph.DataHandler.parseFloat(item[2][1]);
  71   }
  72 };
  73
  74 /** @inheritDoc */
  75 BarsHandler.prototype.getExtremeYValues = function(series, dateWindow, options) {
  76   var minY = null, maxY = null, y;
  77
  78   var firstIdx = 0;
  79   var lastIdx = series.length - 1;
  80
  81   for ( var j = firstIdx; j <= lastIdx; j++) {
  82     y = series[j][1];
  83     if (y === null || isNaN(y)) continue;
  84
  85     var low = series[j][2][0];
  86     var high = series[j][2][1];
  87
  88     if (low > y) low = y; // this can happen with custom bars,
  89     if (high < y) high = y; // e.g. in tests/custom-bars.html
  90
  91     if (maxY === null || high > maxY) maxY = high;
  92     if (minY === null || low < minY) minY = low;
  93   }
  94
  95   return [ minY, maxY ];
  96 };
  97
  98 /** @inheritDoc */
  99 BarsHandler.prototype.onLineEvaluated = function(points, axis, logscale) {
 100   var point;
 101   for (var j = 0; j < points.length; j++) {
 102     // Copy over the error terms
 103     point = points[j];
 104     point.y_top = DygraphLayout.calcYNormal_(axis, point.yval_minus, logscale);
 105     point.y_bottom = DygraphLayout.calcYNormal_(axis, point.yval_plus, logscale);
 106   }
 107 };
 108
 109 })();