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.
67 area
.w
= this.dygraph_
.width_
- area
.x
- this.attr_('rightGap');
68 area
.h
= this.dygraph_
.height_
;
70 // Let plugins reserve space.
72 chart_div
: this.dygraph_
.graphDiv
,
73 reserveSpaceLeft
: function(px
) {
84 reserveSpaceRight
: function(px
) {
86 x
: area
.x
+ area
.w
- px
,
94 reserveSpaceTop
: function(px
) {
105 reserveSpaceBottom
: function(px
) {
108 y
: area
.y
+ area
.h
- px
,
115 chartRect
: function() {
116 return {x
:area
.x
, y
:area
.y
, w
:area
.w
, h
:area
.h
};
119 this.dygraph_
.cascadeEvents_('layout', e
);
121 // Add space for range selector, if needed.
122 if (this.attr_('showRangeSelector')) {
123 area
.h
-= this.attr_('rangeSelectorHeight') + 4;
129 DygraphLayout
.prototype.setAnnotations
= function(ann
) {
130 // The Dygraph object's annotations aren't parsed. We parse them here and
131 // save a copy. If there is no parser, then the user must be using raw format.
132 this.annotations
= [];
133 var parse
= this.attr_('xValueParser') || function(x
) { return x
; };
134 for (var i
= 0; i
< ann
.length
; i
++) {
136 if (!ann
[i
].xval
&& !ann
[i
].x
) {
137 this.dygraph_
.error("Annotations must have an 'x' property");
141 !(ann
[i
].hasOwnProperty('width') &&
142 ann
[i
].hasOwnProperty('height'))) {
143 this.dygraph_
.error("Must set width and height when setting " +
144 "annotation.icon property");
147 Dygraph
.update(a
, ann
[i
]);
148 if (!a
.xval
) a
.xval
= parse(a
.x
);
149 this.annotations
.push(a
);
153 DygraphLayout
.prototype.setXTicks
= function(xTicks
) {
154 this.xTicks_
= xTicks
;
157 // TODO(danvk): add this to the Dygraph object's API or move it into Layout.
158 DygraphLayout
.prototype.setYAxes
= function (yAxes
) {
162 DygraphLayout
.prototype.setDateWindow
= function(dateWindow
) {
163 this.dateWindow_
= dateWindow
;
166 DygraphLayout
.prototype.evaluate
= function() {
167 this._evaluateLimits();
168 this._evaluateLineCharts();
169 this._evaluateLineTicks();
170 this._evaluateAnnotations();
173 DygraphLayout
.prototype._evaluateLimits
= function() {
174 this.minxval
= this.maxxval
= null;
175 if (this.dateWindow_
) {
176 this.minxval
= this.dateWindow_
[0];
177 this.maxxval
= this.dateWindow_
[1];
179 for (var setIdx
= 0; setIdx
< this.datasets
.length
; ++setIdx
) {
180 var series
= this.datasets
[setIdx
];
181 if (series
.length
> 1) {
182 var x1
= series
[0][0];
183 if (!this.minxval
|| x1
< this.minxval
) this.minxval
= x1
;
185 var x2
= series
[series
.length
- 1][0];
186 if (!this.maxxval
|| x2
> this.maxxval
) this.maxxval
= x2
;
190 this.xrange
= this.maxxval
- this.minxval
;
191 this.xscale
= (this.xrange
!== 0 ? 1/this.xrange
: 1.0);
193 for (var i
= 0; i
< this.yAxes_
.length
; i
++) {
194 var axis
= this.yAxes_
[i
];
195 axis
.minyval
= axis
.computedValueRange
[0];
196 axis
.maxyval
= axis
.computedValueRange
[1];
197 axis
.yrange
= axis
.maxyval
- axis
.minyval
;
198 axis
.yscale
= (axis
.yrange
!== 0 ? 1.0 / axis
.yrange
: 1.0);
200 if (axis
.g
.attr_("logscale")) {
201 axis
.ylogrange
= Dygraph
.log10(axis
.maxyval
) - Dygraph
.log10(axis
.minyval
);
202 axis
.ylogscale
= (axis
.ylogrange
!== 0 ? 1.0 / axis
.ylogrange
: 1.0);
203 if (!isFinite(axis
.ylogrange
) || isNaN(axis
.ylogrange
)) {
204 axis
.g
.error('axis ' + i
+ ' of graph at ' + axis
.g
+
205 ' can\'t be displayed in log scale for range [' +
206 axis
.minyval
+ ' - ' + axis
.maxyval
+ ']');
212 DygraphLayout
._calcYNormal
= function(axis
, value
) {
214 return 1.0 - ((Dygraph
.log10(value
) - Dygraph
.log10(axis
.minyval
)) * axis
.ylogscale
);
216 return 1.0 - ((value
- axis
.minyval
) * axis
.yscale
);
220 DygraphLayout
.prototype._evaluateLineCharts
= function() {
221 // An array to keep track of how many points will be drawn for each set.
222 // This will allow for the canvas renderer to not have to check every point
223 // for every data set since the points are added in order of the sets in
225 this.setPointsLengths
= [];
226 this.setPointsOffsets
= [];
228 var connectSeparated
= this.attr_('connectSeparatedPoints');
229 // TODO(bhs): these loops are a hot-spot for high-point-count charts. In fact,
230 // on chrome+linux, they are 6 times more expensive than iterating through the
231 // points and drawing the lines. The brunt of the cost comes from allocating
232 // the |point| structures.
236 // Preallocating the size of points reduces reallocations, and therefore,
237 // calls to collect garbage.
239 for (setIdx
= 0; setIdx
< this.datasets
.length
; ++setIdx
) {
240 totalPoints
+= this.datasets
[setIdx
].length
;
242 this.points
= new Array(totalPoints
);
244 for (setIdx
= 0; setIdx
< this.datasets
.length
; ++setIdx
) {
245 this.setPointsOffsets
.push(i
);
246 var dataset
= this.datasets
[setIdx
];
247 var setName
= this.setNames
[setIdx
];
248 var axis
= this.dygraph_
.axisPropertiesForSeries(setName
);
250 for (var j
= 0; j
< dataset
.length
; j
++) {
251 var item
= dataset
[j
];
252 var xValue
= DygraphLayout
.parseFloat_(item
[0]);
253 var yValue
= DygraphLayout
.parseFloat_(item
[1]);
255 // Range from 0-1 where 0 represents left and 1 represents right.
256 var xNormal
= (xValue
- this.minxval
) * this.xscale
;
257 // Range from 0-1 where 0 represents top and 1 represents bottom
258 var yNormal
= DygraphLayout
._calcYNormal(axis
, yValue
);
260 if (connectSeparated
&& item
[1] === null) {
273 this.setPointsLengths
.push(i
- this.setPointsOffsets
[setIdx
]);
278 * Optimized replacement for parseFloat, which was way too slow when almost
279 * all values were type number, with few edge cases, none of which were strings.
281 DygraphLayout
.parseFloat_
= function(val
) {
282 // parseFloat(null) is NaN
287 // Assume it's a number or NaN. If it's something else, I'll be shocked.
291 DygraphLayout
.prototype._evaluateLineTicks
= function() {
292 var i
, tick
, label
, pos
;
294 for (i
= 0; i
< this.xTicks_
.length
; i
++) {
295 tick
= this.xTicks_
[i
];
297 pos
= this.xscale
* (tick
.v
- this.minxval
);
298 if ((pos
>= 0.0) && (pos
<= 1.0)) {
299 this.xticks
.push([pos
, label
]);
304 for (i
= 0; i
< this.yAxes_
.length
; i
++ ) {
305 var axis
= this.yAxes_
[i
];
306 for (var j
= 0; j
< axis
.ticks
.length
; j
++) {
307 tick
= axis
.ticks
[j
];
309 pos
= this.dygraph_
.toPercentYCoord(tick
.v
, i
);
310 if ((pos
>= 0.0) && (pos
<= 1.0)) {
311 this.yticks
.push([i
, pos
, label
]);
319 * Behaves the same way as PlotKit.Layout, but also copies the errors
322 DygraphLayout
.prototype.evaluateWithError
= function() {
324 if (!(this.attr_('errorBars') || this.attr_('customBars'))) return;
326 // Copy over the error terms
327 var i
= 0; // index in this.points
328 for (var setIdx
= 0; setIdx
< this.datasets
.length
; ++setIdx
) {
330 var dataset
= this.datasets
[setIdx
];
331 var setName
= this.setNames
[setIdx
];
332 var axis
= this.dygraph_
.axisPropertiesForSeries(setName
);
333 for (j
= 0; j
< dataset
.length
; j
++, i
++) {
334 var item
= dataset
[j
];
335 var xv
= DygraphLayout
.parseFloat_(item
[0]);
336 var yv
= DygraphLayout
.parseFloat_(item
[1]);
338 if (xv
== this.points
[i
].xval
&&
339 yv
== this.points
[i
].yval
) {
340 var errorMinus
= DygraphLayout
.parseFloat_(item
[2]);
341 var errorPlus
= DygraphLayout
.parseFloat_(item
[3]);
343 var yv_minus
= yv
- errorMinus
;
344 var yv_plus
= yv
+ errorPlus
;
345 this.points
[i
].y_top
= DygraphLayout
._calcYNormal(axis
, yv_minus
);
346 this.points
[i
].y_bottom
= DygraphLayout
._calcYNormal(axis
, yv_plus
);
352 DygraphLayout
.prototype._evaluateAnnotations
= function() {
353 // Add the annotations to the point to which they belong.
354 // Make a map from (setName, xval) to annotation for quick lookups.
356 var annotations
= {};
357 for (i
= 0; i
< this.annotations
.length
; i
++) {
358 var a
= this.annotations
[i
];
359 annotations
[a
.xval
+ "," + a
.series
] = a
;
362 this.annotated_points
= [];
364 // Exit the function early if there are no annotations.
365 if (!this.annotations
|| !this.annotations
.length
) {
369 // TODO(antrob): loop through annotations not points.
370 for (i
= 0; i
< this.points
.length
; i
++) {
371 var p
= this.points
[i
];
372 var k
= p
.xval
+ "," + p
.name
;
373 if (k
in annotations
) {
374 p
.annotation
= annotations
[k
];
375 this.annotated_points
.push(p
);
381 * Convenience function to remove all the data sets from a graph
383 DygraphLayout
.prototype.removeAllDatasets
= function() {
384 delete this.datasets
;
385 delete this.setNames
;
386 delete this.setPointsLengths
;
387 delete this.setPointsOffsets
;
390 this.setPointsLengths
= [];
391 this.setPointsOffsets
= [];
395 * Return a copy of the point at the indicated index, with its yval unstacked.
396 * @param int index of point in layout_.points
398 DygraphLayout
.prototype.unstackPointAtIndex
= function(idx
) {
399 var point
= this.points
[idx
];
400 // If the point is missing, no unstacking is necessary
405 // Clone the point since we modify it
406 var unstackedPoint
= {};
407 for (var pt
in point
) {
408 unstackedPoint
[pt
] = point
[pt
];
411 if (!this.attr_("stackedGraph")) {
412 return unstackedPoint
;
415 // The unstacked yval is equal to the current yval minus the yval of the
416 // next point at the same xval.
417 for (var i
= idx
+1; i
< this.points
.length
; i
++) {
418 if ((this.points
[i
].xval
== point
.xval
) && this.points
[i
].yval
) {
419 unstackedPoint
.yval
-= this.points
[i
].yval
;
424 return unstackedPoint
;