3 * Copyright 2011 Dan Vanderkam (danvdk@gmail.com)
4 * MIT-licensed (http://opensource.org/licenses/MIT)
8 * @fileoverview Based on PlotKitLayout, but modified to meet the needs of
12 /*jshint globalstrict: true */
13 /*global Dygraph:false */
17 * Creates a new DygraphLayout object.
19 * This class contains all the data to be charted.
20 * It uses data coordinates, but also records the chart range (in data
21 * coordinates) and hence is able to calculate percentage positions ('In this
22 * view, Point A lies 25% down the x-axis.')
24 * Two things that it does not do are:
25 * 1. Record pixel coordinates for anything.
26 * 2. (oddly) determine anything about the layout of chart elements.
28 * The naming is a vestige of Dygraph's original PlotKit roots.
32 var DygraphLayout
= function(dygraph
) {
33 this.dygraph_
= dygraph
;
36 this.annotations
= [];
39 // TODO(danvk): it's odd that xTicks_ and yTicks_ are inputs, but xticks and
40 // yticks are outputs. Clean this up.
45 DygraphLayout
.prototype.attr_
= function(name
) {
46 return this.dygraph_
.attr_(name
);
49 DygraphLayout
.prototype.addDataset
= function(setname
, set_xy
) {
50 this.datasets
.push(set_xy
);
51 this.setNames
.push(setname
);
54 DygraphLayout
.prototype.getPlotArea
= function() {
55 return this.computePlotArea_();
58 // Compute the box which the chart should be drawn in. This is the canvas's
59 // box, less space needed for axis and chart labels.
60 DygraphLayout
.prototype.computePlotArea_
= function() {
62 // TODO(danvk): per-axis setting.
66 if (this.attr_('drawYAxis')) {
67 area
.x
= this.attr_('yAxisLabelWidth') + 2 * this.attr_('axisTickSize');
70 area
.w
= this.dygraph_
.width_
- area
.x
- this.attr_('rightGap');
71 area
.h
= this.dygraph_
.height_
;
72 if (this.attr_('drawXAxis')) {
73 if (this.attr_('xAxisHeight')) {
74 area
.h
-= this.attr_('xAxisHeight');
76 area
.h
-= this.attr_('axisLabelFontSize') + 2 * this.attr_('axisTickSize');
80 // Shrink the drawing area to accomodate additional y-axes.
81 if (this.dygraph_
.numAxes() == 2) {
82 // TODO(danvk): per-axis setting.
83 area
.w
-= (this.attr_('yAxisLabelWidth') + 2 * this.attr_('axisTickSize'));
84 } else if (this.dygraph_
.numAxes() > 2) {
85 this.dygraph_
.error("Only two y-axes are supported at this time. (Trying " +
86 "to use " + this.dygraph_
.numAxes() + ")");
89 // Add space for chart labels: title, xlabel and ylabel.
90 if (this.attr_('title')) {
91 area
.h
-= this.attr_('titleHeight');
92 area
.y
+= this.attr_('titleHeight');
94 if (this.attr_('xlabel')) {
95 area
.h
-= this.attr_('xLabelHeight');
97 if (this.attr_('ylabel')) {
98 // It would make sense to shift the chart here to make room for the y-axis
99 // label, but the default yAxisLabelWidth is large enough that this results
100 // in overly-padded charts. The y-axis label should fit fine. If it
101 // doesn't, the yAxisLabelWidth option can be increased.
104 if (this.attr_('y2label')) {
105 // same logic applies here as for ylabel.
106 // TODO(danvk): make yAxisLabelWidth a per-axis property
109 // Add space for range selector, if needed.
110 if (this.attr_('showRangeSelector')) {
111 area
.h
-= this.attr_('rangeSelectorHeight') + 4;
117 DygraphLayout
.prototype.setAnnotations
= function(ann
) {
118 // The Dygraph object's annotations aren't parsed. We parse them here and
119 // save a copy. If there is no parser, then the user must be using raw format.
120 this.annotations
= [];
121 var parse
= this.attr_('xValueParser') || function(x
) { return x
; };
122 for (var i
= 0; i
< ann
.length
; i
++) {
124 if (!ann
[i
].xval
&& !ann
[i
].x
) {
125 this.dygraph_
.error("Annotations must have an 'x' property");
129 !(ann
[i
].hasOwnProperty('width') &&
130 ann
[i
].hasOwnProperty('height'))) {
131 this.dygraph_
.error("Must set width and height when setting " +
132 "annotation.icon property");
135 Dygraph
.update(a
, ann
[i
]);
136 if (!a
.xval
) a
.xval
= parse(a
.x
);
137 this.annotations
.push(a
);
141 DygraphLayout
.prototype.setXTicks
= function(xTicks
) {
142 this.xTicks_
= xTicks
;
145 // TODO(danvk): add this to the Dygraph object's API or move it into Layout.
146 DygraphLayout
.prototype.setYAxes
= function (yAxes
) {
150 DygraphLayout
.prototype.setDateWindow
= function(dateWindow
) {
151 this.dateWindow_
= dateWindow
;
154 DygraphLayout
.prototype.evaluate
= function() {
155 this._evaluateLimits();
156 this._evaluateLineCharts();
157 this._evaluateLineTicks();
158 this._evaluateAnnotations();
161 DygraphLayout
.prototype._evaluateLimits
= function() {
162 this.minxval
= this.maxxval
= null;
163 if (this.dateWindow_
) {
164 this.minxval
= this.dateWindow_
[0];
165 this.maxxval
= this.dateWindow_
[1];
167 for (var setIdx
= 0; setIdx
< this.datasets
.length
; ++setIdx
) {
168 var series
= this.datasets
[setIdx
];
169 if (series
.length
> 1) {
170 var x1
= series
[0][0];
171 if (!this.minxval
|| x1
< this.minxval
) this.minxval
= x1
;
173 var x2
= series
[series
.length
- 1][0];
174 if (!this.maxxval
|| x2
> this.maxxval
) this.maxxval
= x2
;
178 this.xrange
= this.maxxval
- this.minxval
;
179 this.xscale
= (this.xrange
!== 0 ? 1/this.xrange
: 1.0);
181 for (var i
= 0; i
< this.yAxes_
.length
; i
++) {
182 var axis
= this.yAxes_
[i
];
183 axis
.minyval
= axis
.computedValueRange
[0];
184 axis
.maxyval
= axis
.computedValueRange
[1];
185 axis
.yrange
= axis
.maxyval
- axis
.minyval
;
186 axis
.yscale
= (axis
.yrange
!== 0 ? 1.0 / axis
.yrange
: 1.0);
188 if (axis
.g
.attr_("logscale")) {
189 axis
.ylogrange
= Dygraph
.log10(axis
.maxyval
) - Dygraph
.log10(axis
.minyval
);
190 axis
.ylogscale
= (axis
.ylogrange
!== 0 ? 1.0 / axis
.ylogrange
: 1.0);
191 if (!isFinite(axis
.ylogrange
) || isNaN(axis
.ylogrange
)) {
192 axis
.g
.error('axis ' + i
+ ' of graph at ' + axis
.g
+
193 ' can\'t be displayed in log scale for range [' +
194 axis
.minyval
+ ' - ' + axis
.maxyval
+ ']');
200 DygraphLayout
._calcYNormal
= function(axis
, value
) {
202 return 1.0 - ((Dygraph
.log10(value
) - Dygraph
.log10(axis
.minyval
)) * axis
.ylogscale
);
204 return 1.0 - ((value
- axis
.minyval
) * axis
.yscale
);
208 DygraphLayout
.prototype._evaluateLineCharts
= function() {
211 // An array to keep track of how many points will be drawn for each set.
212 // This will allow for the canvas renderer to not have to check every point
213 // for every data set since the points are added in order of the sets in
215 this.setPointsLengths
= [];
216 this.setPointsOffsets
= [];
218 var connectSeparated
= this.attr_('connectSeparatedPoints');
219 for (var setIdx
= 0; setIdx
< this.datasets
.length
; ++setIdx
) {
220 var dataset
= this.datasets
[setIdx
];
221 var setName
= this.setNames
[setIdx
];
222 var axis
= this.dygraph_
.axisPropertiesForSeries(setName
);
224 this.setPointsOffsets
.push(this.points
.length
);
225 var setPointsLength
= 0;
227 for (var j
= 0; j
< dataset
.length
; j
++) {
228 var item
= dataset
[j
];
229 var xValue
= parseFloat(item
[0]);
230 var yValue
= parseFloat(item
[1]);
232 // Range from 0-1 where 0 represents left and 1 represents right.
233 var xNormal
= (xValue
- this.minxval
) * this.xscale
;
234 // Range from 0-1 where 0 represents top and 1 represents bottom
235 var yNormal
= DygraphLayout
._calcYNormal(axis
, yValue
);
245 if (connectSeparated
&& item
[1] === null) {
248 this.points
.push(point
);
249 setPointsLength
+= 1;
251 this.setPointsLengths
.push(setPointsLength
);
255 DygraphLayout
.prototype._evaluateLineTicks
= function() {
256 var i
, tick
, label
, pos
;
258 for (i
= 0; i
< this.xTicks_
.length
; i
++) {
259 tick
= this.xTicks_
[i
];
261 pos
= this.xscale
* (tick
.v
- this.minxval
);
262 if ((pos
>= 0.0) && (pos
<= 1.0)) {
263 this.xticks
.push([pos
, label
]);
268 for (i
= 0; i
< this.yAxes_
.length
; i
++ ) {
269 var axis
= this.yAxes_
[i
];
270 for (var j
= 0; j
< axis
.ticks
.length
; j
++) {
271 tick
= axis
.ticks
[j
];
273 pos
= this.dygraph_
.toPercentYCoord(tick
.v
, i
);
274 if ((pos
>= 0.0) && (pos
<= 1.0)) {
275 this.yticks
.push([i
, pos
, label
]);
283 * Behaves the same way as PlotKit.Layout, but also copies the errors
286 DygraphLayout
.prototype.evaluateWithError
= function() {
288 if (!(this.attr_('errorBars') || this.attr_('customBars'))) return;
290 // Copy over the error terms
291 var i
= 0; // index in this.points
292 for (var setIdx
= 0; setIdx
< this.datasets
.length
; ++setIdx
) {
294 var dataset
= this.datasets
[setIdx
];
295 var setName
= this.setNames
[setIdx
];
296 var axis
= this.dygraph_
.axisPropertiesForSeries(setName
);
297 for (j
= 0; j
< dataset
.length
; j
++, i
++) {
298 var item
= dataset
[j
];
299 var xv
= parseFloat(item
[0]);
300 var yv
= parseFloat(item
[1]);
302 if (xv
== this.points
[i
].xval
&&
303 yv
== this.points
[i
].yval
) {
304 var errorMinus
= parseFloat(item
[2]);
305 var errorPlus
= parseFloat(item
[3]);
307 var yv_minus
= yv
- errorMinus
;
308 var yv_plus
= yv
+ errorPlus
;
309 this.points
[i
].y_top
= DygraphLayout
._calcYNormal(axis
, yv_minus
);
310 this.points
[i
].y_bottom
= DygraphLayout
._calcYNormal(axis
, yv_plus
);
316 DygraphLayout
.prototype._evaluateAnnotations
= function() {
317 // Add the annotations to the point to which they belong.
318 // Make a map from (setName, xval) to annotation for quick lookups.
320 var annotations
= {};
321 for (i
= 0; i
< this.annotations
.length
; i
++) {
322 var a
= this.annotations
[i
];
323 annotations
[a
.xval
+ "," + a
.series
] = a
;
326 this.annotated_points
= [];
328 // Exit the function early if there are no annotations.
329 if (!this.annotations
|| !this.annotations
.length
) {
333 // TODO(antrob): loop through annotations not points.
334 for (i
= 0; i
< this.points
.length
; i
++) {
335 var p
= this.points
[i
];
336 var k
= p
.xval
+ "," + p
.name
;
337 if (k
in annotations
) {
338 p
.annotation
= annotations
[k
];
339 this.annotated_points
.push(p
);
345 * Convenience function to remove all the data sets from a graph
347 DygraphLayout
.prototype.removeAllDatasets
= function() {
348 delete this.datasets
;
349 delete this.setNames
;
350 delete this.setPointsLengths
;
351 delete this.setPointsOffsets
;
354 this.setPointsLengths
= [];
355 this.setPointsOffsets
= [];
359 * Return a copy of the point at the indicated index, with its yval unstacked.
360 * @param int index of point in layout_.points
362 DygraphLayout
.prototype.unstackPointAtIndex
= function(idx
) {
363 var point
= this.points
[idx
];
365 // Clone the point since we modify it
366 var unstackedPoint
= {};
367 for (var pt
in point
) {
368 unstackedPoint
[pt
] = point
[pt
];
371 if (!this.attr_("stackedGraph")) {
372 return unstackedPoint
;
375 // The unstacked yval is equal to the current yval minus the yval of the
376 // next point at the same xval.
377 for (var i
= idx
+1; i
< this.points
.length
; i
++) {
378 if (this.points
[i
].xval
== point
.xval
) {
379 unstackedPoint
.yval
-= this.points
[i
].yval
;
384 return unstackedPoint
;