Merge branch 'master' of https://github.com/kberg/dygraphs
[dygraphs.git] / dygraph-layout.js
1 // Copyright 2011 Dan Vanderkam (danvdk@gmail.com)
2 // All Rights Reserved.
3
4 /**
5 * @fileoverview Based on PlotKitLayout, but modified to meet the needs of
6 * dygraphs.
7 */
8
9 /**
10 * Creates a new DygraphLayout object.
11 *
12 * This class contains all the data to be charted.
13 * It uses data coordinates, but also records the chart range (in data
14 * coordinates) and hence is able to calculate percentage positions ('In this
15 * view, Point A lies 25% down the x-axis.')
16 *
17 * Two things that it does not do are:
18 * 1. Record pixel coordinates for anything.
19 * 2. (oddly) determine anything about the layout of chart elements.
20 *
21 * The naming is a vestige of Dygraph's original PlotKit roots.
22 *
23 * @constructor
24 */
25 DygraphLayout = function(dygraph) {
26 this.dygraph_ = dygraph;
27 this.datasets = new Array();
28 this.annotations = new Array();
29 this.yAxes_ = null;
30
31 // TODO(danvk): it's odd that xTicks_ and yTicks_ are inputs, but xticks and
32 // yticks are outputs. Clean this up.
33 this.xTicks_ = null;
34 this.yTicks_ = null;
35 };
36
37 DygraphLayout.prototype.attr_ = function(name) {
38 return this.dygraph_.attr_(name);
39 };
40
41 DygraphLayout.prototype.addDataset = function(setname, set_xy) {
42 this.datasets[setname] = set_xy;
43 };
44
45 DygraphLayout.prototype.setAnnotations = function(ann) {
46 // The Dygraph object's annotations aren't parsed. We parse them here and
47 // save a copy. If there is no parser, then the user must be using raw format.
48 this.annotations = [];
49 var parse = this.attr_('xValueParser') || function(x) { return x; };
50 for (var i = 0; i < ann.length; i++) {
51 var a = {};
52 if (!ann[i].xval && !ann[i].x) {
53 this.dygraph_.error("Annotations must have an 'x' property");
54 return;
55 }
56 if (ann[i].icon &&
57 !(ann[i].hasOwnProperty('width') &&
58 ann[i].hasOwnProperty('height'))) {
59 this.dygraph_.error("Must set width and height when setting " +
60 "annotation.icon property");
61 return;
62 }
63 Dygraph.update(a, ann[i]);
64 if (!a.xval) a.xval = parse(a.x);
65 this.annotations.push(a);
66 }
67 };
68
69 DygraphLayout.prototype.setXTicks = function(xTicks) {
70 this.xTicks_ = xTicks;
71 };
72
73 // TODO(danvk): add this to the Dygraph object's API or move it into Layout.
74 DygraphLayout.prototype.setYAxes = function (yAxes) {
75 this.yAxes_ = yAxes;
76 };
77
78 DygraphLayout.prototype.setDateWindow = function(dateWindow) {
79 this.dateWindow_ = dateWindow;
80 };
81
82 DygraphLayout.prototype.evaluate = function() {
83 this._evaluateLimits();
84 this._evaluateLineCharts();
85 this._evaluateLineTicks();
86 this._evaluateAnnotations();
87 };
88
89 DygraphLayout.prototype._evaluateLimits = function() {
90 this.minxval = this.maxxval = null;
91 if (this.dateWindow_) {
92 this.minxval = this.dateWindow_[0];
93 this.maxxval = this.dateWindow_[1];
94 } else {
95 for (var name in this.datasets) {
96 if (!this.datasets.hasOwnProperty(name)) continue;
97 var series = this.datasets[name];
98 if (series.length > 1) {
99 var x1 = series[0][0];
100 if (!this.minxval || x1 < this.minxval) this.minxval = x1;
101
102 var x2 = series[series.length - 1][0];
103 if (!this.maxxval || x2 > this.maxxval) this.maxxval = x2;
104 }
105 }
106 }
107 this.xrange = this.maxxval - this.minxval;
108 this.xscale = (this.xrange != 0 ? 1/this.xrange : 1.0);
109
110 for (var i = 0; i < this.yAxes_.length; i++) {
111 var axis = this.yAxes_[i];
112 axis.minyval = axis.computedValueRange[0];
113 axis.maxyval = axis.computedValueRange[1];
114 axis.yrange = axis.maxyval - axis.minyval;
115 axis.yscale = (axis.yrange != 0 ? 1.0 / axis.yrange : 1.0);
116
117 if (axis.g.attr_("logscale")) {
118 axis.ylogrange = Dygraph.log10(axis.maxyval) - Dygraph.log10(axis.minyval);
119 axis.ylogscale = (axis.ylogrange != 0 ? 1.0 / axis.ylogrange : 1.0);
120 if (!isFinite(axis.ylogrange) || isNaN(axis.ylogrange)) {
121 axis.g.error('axis ' + i + ' of graph at ' + axis.g +
122 ' can\'t be displayed in log scale for range [' +
123 axis.minyval + ' - ' + axis.maxyval + ']');
124 }
125 }
126 }
127 };
128
129 DygraphLayout.prototype._evaluateLineCharts = function() {
130 // add all the rects
131 this.points = new Array();
132 for (var setName in this.datasets) {
133 if (!this.datasets.hasOwnProperty(setName)) continue;
134
135 var dataset = this.datasets[setName];
136 var axis = this.dygraph_.axisPropertiesForSeries(setName);
137
138 for (var j = 0; j < dataset.length; j++) {
139 var item = dataset[j];
140
141 var yval;
142 if (axis.logscale) {
143 yval = 1.0 - ((Dygraph.log10(parseFloat(item[1])) - Dygraph.log10(axis.minyval)) * axis.ylogscale); // really should just be yscale.
144 } else {
145 yval = 1.0 - ((parseFloat(item[1]) - axis.minyval) * axis.yscale);
146 }
147 var point = {
148 // TODO(danvk): here
149 x: ((parseFloat(item[0]) - this.minxval) * this.xscale),
150 y: yval,
151 xval: parseFloat(item[0]),
152 yval: parseFloat(item[1]),
153 name: setName
154 };
155
156 this.points.push(point);
157 }
158 }
159 };
160
161 DygraphLayout.prototype._evaluateLineTicks = function() {
162 this.xticks = new Array();
163 for (var i = 0; i < this.xTicks_.length; i++) {
164 var tick = this.xTicks_[i];
165 var label = tick.label;
166 var pos = this.xscale * (tick.v - this.minxval);
167 if ((pos >= 0.0) && (pos <= 1.0)) {
168 this.xticks.push([pos, label]);
169 }
170 }
171
172 this.yticks = new Array();
173 for (var i = 0; i < this.yAxes_.length; i++ ) {
174 var axis = this.yAxes_[i];
175 for (var j = 0; j < axis.ticks.length; j++) {
176 var tick = axis.ticks[j];
177 var label = tick.label;
178 var pos = this.dygraph_.toPercentYCoord(tick.v, i);
179 if ((pos >= 0.0) && (pos <= 1.0)) {
180 this.yticks.push([i, pos, label]);
181 }
182 }
183 }
184 };
185
186
187 /**
188 * Behaves the same way as PlotKit.Layout, but also copies the errors
189 * @private
190 */
191 DygraphLayout.prototype.evaluateWithError = function() {
192 this.evaluate();
193 if (!(this.attr_('errorBars') || this.attr_('customBars'))) return;
194
195 // Copy over the error terms
196 var i = 0; // index in this.points
197 for (var setName in this.datasets) {
198 if (!this.datasets.hasOwnProperty(setName)) continue;
199 var j = 0;
200 var dataset = this.datasets[setName];
201 for (var j = 0; j < dataset.length; j++, i++) {
202 var item = dataset[j];
203 var xv = parseFloat(item[0]);
204 var yv = parseFloat(item[1]);
205
206 if (xv == this.points[i].xval &&
207 yv == this.points[i].yval) {
208 this.points[i].errorMinus = parseFloat(item[2]);
209 this.points[i].errorPlus = parseFloat(item[3]);
210 }
211 }
212 }
213 };
214
215 DygraphLayout.prototype._evaluateAnnotations = function() {
216 // Add the annotations to the point to which they belong.
217 // Make a map from (setName, xval) to annotation for quick lookups.
218 var annotations = {};
219 for (var i = 0; i < this.annotations.length; i++) {
220 var a = this.annotations[i];
221 annotations[a.xval + "," + a.series] = a;
222 }
223
224 this.annotated_points = [];
225 for (var i = 0; i < this.points.length; i++) {
226 var p = this.points[i];
227 var k = p.xval + "," + p.name;
228 if (k in annotations) {
229 p.annotation = annotations[k];
230 this.annotated_points.push(p);
231 }
232 }
233 };
234
235 /**
236 * Convenience function to remove all the data sets from a graph
237 */
238 DygraphLayout.prototype.removeAllDatasets = function() {
239 delete this.datasets;
240 this.datasets = new Array();
241 };
242
243 /**
244 * Return a copy of the point at the indicated index, with its yval unstacked.
245 * @param int index of point in layout_.points
246 */
247 DygraphLayout.prototype.unstackPointAtIndex = function(idx) {
248 var point = this.points[idx];
249
250 // Clone the point since we modify it
251 var unstackedPoint = {};
252 for (var i in point) {
253 unstackedPoint[i] = point[i];
254 }
255
256 if (!this.attr_("stackedGraph")) {
257 return unstackedPoint;
258 }
259
260 // The unstacked yval is equal to the current yval minus the yval of the
261 // next point at the same xval.
262 for (var i = idx+1; i < this.points.length; i++) {
263 if (this.points[i].xval == point.xval) {
264 unstackedPoint.yval -= this.points[i].yval;
265 break;
266 }
267 }
268
269 return unstackedPoint;
270 }