plotkit_v091/PlotKit/Layout.js

   1 /*
   2     PlotKit Layout
   3     ==============
   4
   5     Handles laying out data on to a virtual canvas square canvas between 0.0
   6     and 1.0. If you want to add new chart/plot types such as point plots,
   7     you need to add them here.
   8
   9     Copyright
  10     ---------
  11     Copyright 2005,2006 (c) Alastair Tse <alastair^liquidx.net>
  12     For use under the BSD license. <http://www.liquidx.net/plotkit>
  13
  14 */
  15
  16 // --------------------------------------------------------------------
  17 // Start of Layout definition
  18 // --------------------------------------------------------------------
  19
  20 if (typeof(PlotKit.Layout) == 'undefined') {
  21     PlotKit.Layout = {};
  22 }
  23
  24 // --------------------------------------------------------------------
  25 // Start of Layout definition
  26 // --------------------------------------------------------------------
  27
  28 PlotKit.Layout = function(style, options) {
  29     this.options = { };
  30
  31     // valid external options : TODO: input verification
  32     MochiKit.Base.update(this.options, options ? options : {});
  33
  34     // internal states
  35     this.datasets = new Array();
  36 };
  37
  38 // --------------------------------------------------------------------
  39 // Dataset Manipulation
  40 // --------------------------------------------------------------------
  41
  42
  43 PlotKit.Layout.prototype.addDataset = function(setname, set_xy) {
  44     this.datasets[setname] = set_xy;
  45 };
  46
  47 // --------------------------------------------------------------------
  48 // Evaluates the layout for the current data and style.
  49 // --------------------------------------------------------------------
  50
  51 PlotKit.Layout.prototype.evaluate = function() {
  52     this._evaluateLimits();
  53     this._evaluateLineCharts();
  54     this._evaluateLineTicks();
  55 };
  56
  57
  58 // --------------------------------------------------------------------
  59 // START Internal Functions
  60 // --------------------------------------------------------------------
  61
  62 PlotKit.Layout.prototype._evaluateLimits = function() {
  63     this.minxval = this.maxxval = null;
  64     for (var name in this.datasets) {
  65       var series = this.datasets[name];
  66       var x1 = series[0][0];
  67       if (!this.minxval || x1 < this.minxval) this.minxval = x1;
  68
  69       var x2 = series[series.length - 1][0];
  70       if (!this.maxxval || x2 > this.maxxval) this.maxxval = x2;
  71     }
  72     this.xrange = this.maxxval - this.minxval;
  73     this.xscale = (this.xrange != 0 ? 1/this.xrange : 1.0);
  74
  75     this.minyval = this.options.yAxis[0];
  76     this.maxyval = this.options.yAxis[1];
  77     this.yrange = this.maxyval - this.minyval;
  78     this.yscale = (this.yrange != 0 ? 1/this.yrange : 1.0);
  79 };
  80
  81 // Create the line charts
  82 PlotKit.Layout.prototype._evaluateLineCharts = function() {
  83     var items = PlotKit.Base.items;
  84
  85     var setCount = items(this.datasets).length;
  86
  87     // add all the rects
  88     this.points = new Array();
  89     for (var setName in this.datasets) {
  90         var dataset = this.datasets[setName];
  91         for (var j = 0; j < dataset.length; j++) {
  92             var item = dataset[j];
  93             var point = {
  94                 x: ((parseFloat(item[0]) - this.minxval) * this.xscale),
  95                 y: 1.0 - ((parseFloat(item[1]) - this.minyval) * this.yscale),
  96                 xval: parseFloat(item[0]),
  97                 yval: parseFloat(item[1]),
  98                 name: setName
  99             };
 100
 101             // limit the x, y values so they do not overdraw
 102             if (point.y <= 0.0) {
 103                 point.y = 0.0;
 104             }
 105             if (point.y >= 1.0) {
 106                 point.y = 1.0;
 107             }
 108             if ((point.x >= 0.0) && (point.x <= 1.0)) {
 109                 this.points.push(point);
 110             }
 111         }
 112     }
 113 };
 114
 115 PlotKit.Layout.prototype._evaluateLineTicks = function() {
 116   this.xticks = new Array();
 117   for (var i = 0; i < this.options.xTicks.length; i++) {
 118     var tick = this.options.xTicks[i];
 119     var label = tick.label;
 120     var pos = this.xscale * (tick.v - this.minxval);
 121     if ((pos >= 0.0) && (pos <= 1.0)) {
 122       this.xticks.push([pos, label]);
 123     }
 124   }
 125
 126   this.yticks = new Array();
 127   for (var i = 0; i < this.options.yTicks.length; i++) {
 128     var tick = this.options.yTicks[i];
 129     var label = tick.label;
 130     var pos = 1.0 - (this.yscale * (tick.v - this.minyval));
 131     if ((pos >= 0.0) && (pos <= 1.0)) {
 132       this.yticks.push([pos, label]);
 133     }
 134   }
 135 };
 136