| 1 | // Copyright 2006 Dan Vanderkam (danvdk@gmail.com) |
| 2 | // All Rights Reserved. |
| 3 | |
| 4 | /** |
| 5 | * @fileoverview Subclasses various parts of PlotKit to meet the additional |
| 6 | * needs of Dygraph: grid overlays and error bars |
| 7 | */ |
| 8 | |
| 9 | // Subclass PlotKit.Layout to add: |
| 10 | // 1. Sigma/errorBars properties |
| 11 | // 2. Copy error terms for PlotKit.CanvasRenderer._renderLineChart |
| 12 | |
| 13 | /** |
| 14 | * Creates a new DygraphLayout object. Options are the same as those allowed |
| 15 | * by the PlotKit.Layout constructor. |
| 16 | * @param {Object} options Options for PlotKit.Layout |
| 17 | * @return {Object} The DygraphLayout object |
| 18 | */ |
| 19 | DygraphLayout = function(dygraph, options) { |
| 20 | this.dygraph_ = dygraph; |
| 21 | this.options = {}; // TODO(danvk): remove, use attr_ instead. |
| 22 | MochiKit.Base.update(this.options, options ? options : {}); |
| 23 | this.datasets = new Array(); |
| 24 | }; |
| 25 | |
| 26 | DygraphLayout.prototype.attr_ = function(name) { |
| 27 | return this.dygraph_.attr_(name); |
| 28 | }; |
| 29 | |
| 30 | DygraphLayout.prototype.addDataset = function(setname, set_xy) { |
| 31 | this.datasets[setname] = set_xy; |
| 32 | }; |
| 33 | |
| 34 | DygraphLayout.prototype.evaluate = function() { |
| 35 | this._evaluateLimits(); |
| 36 | this._evaluateLineCharts(); |
| 37 | this._evaluateLineTicks(); |
| 38 | }; |
| 39 | |
| 40 | DygraphLayout.prototype._evaluateLimits = function() { |
| 41 | this.minxval = this.maxxval = null; |
| 42 | for (var name in this.datasets) { |
| 43 | var series = this.datasets[name]; |
| 44 | var x1 = series[0][0]; |
| 45 | if (!this.minxval || x1 < this.minxval) this.minxval = x1; |
| 46 | |
| 47 | var x2 = series[series.length - 1][0]; |
| 48 | if (!this.maxxval || x2 > this.maxxval) this.maxxval = x2; |
| 49 | } |
| 50 | this.xrange = this.maxxval - this.minxval; |
| 51 | this.xscale = (this.xrange != 0 ? 1/this.xrange : 1.0); |
| 52 | |
| 53 | this.minyval = this.options.yAxis[0]; |
| 54 | this.maxyval = this.options.yAxis[1]; |
| 55 | this.yrange = this.maxyval - this.minyval; |
| 56 | this.yscale = (this.yrange != 0 ? 1/this.yrange : 1.0); |
| 57 | }; |
| 58 | |
| 59 | DygraphLayout.prototype._evaluateLineCharts = function() { |
| 60 | // add all the rects |
| 61 | this.points = new Array(); |
| 62 | for (var setName in this.datasets) { |
| 63 | var dataset = this.datasets[setName]; |
| 64 | for (var j = 0; j < dataset.length; j++) { |
| 65 | var item = dataset[j]; |
| 66 | var point = { |
| 67 | x: ((parseFloat(item[0]) - this.minxval) * this.xscale), |
| 68 | y: 1.0 - ((parseFloat(item[1]) - this.minyval) * this.yscale), |
| 69 | xval: parseFloat(item[0]), |
| 70 | yval: parseFloat(item[1]), |
| 71 | name: setName |
| 72 | }; |
| 73 | |
| 74 | // limit the x, y values so they do not overdraw |
| 75 | if (point.y <= 0.0) { |
| 76 | point.y = 0.0; |
| 77 | } |
| 78 | if (point.y >= 1.0) { |
| 79 | point.y = 1.0; |
| 80 | } |
| 81 | if ((point.x >= 0.0) && (point.x <= 1.0)) { |
| 82 | this.points.push(point); |
| 83 | } |
| 84 | } |
| 85 | } |
| 86 | }; |
| 87 | |
| 88 | DygraphLayout.prototype._evaluateLineTicks = function() { |
| 89 | this.xticks = new Array(); |
| 90 | for (var i = 0; i < this.options.xTicks.length; i++) { |
| 91 | var tick = this.options.xTicks[i]; |
| 92 | var label = tick.label; |
| 93 | var pos = this.xscale * (tick.v - this.minxval); |
| 94 | if ((pos >= 0.0) && (pos <= 1.0)) { |
| 95 | this.xticks.push([pos, label]); |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | this.yticks = new Array(); |
| 100 | for (var i = 0; i < this.options.yTicks.length; i++) { |
| 101 | var tick = this.options.yTicks[i]; |
| 102 | var label = tick.label; |
| 103 | var pos = 1.0 - (this.yscale * (tick.v - this.minyval)); |
| 104 | if ((pos >= 0.0) && (pos <= 1.0)) { |
| 105 | this.yticks.push([pos, label]); |
| 106 | } |
| 107 | } |
| 108 | }; |
| 109 | |
| 110 | |
| 111 | /** |
| 112 | * Behaves the same way as PlotKit.Layout, but also copies the errors |
| 113 | * @private |
| 114 | */ |
| 115 | DygraphLayout.prototype.evaluateWithError = function() { |
| 116 | this.evaluate(); |
| 117 | if (!this.options.errorBars) return; |
| 118 | |
| 119 | // Copy over the error terms |
| 120 | var i = 0; // index in this.points |
| 121 | for (var setName in this.datasets) { |
| 122 | var j = 0; |
| 123 | var dataset = this.datasets[setName]; |
| 124 | if (PlotKit.Base.isFuncLike(dataset)) continue; |
| 125 | for (var j = 0; j < dataset.length; j++, i++) { |
| 126 | var item = dataset[j]; |
| 127 | var xv = parseFloat(item[0]); |
| 128 | var yv = parseFloat(item[1]); |
| 129 | |
| 130 | if (xv == this.points[i].xval && |
| 131 | yv == this.points[i].yval) { |
| 132 | this.points[i].errorMinus = parseFloat(item[2]); |
| 133 | this.points[i].errorPlus = parseFloat(item[3]); |
| 134 | } |
| 135 | } |
| 136 | } |
| 137 | }; |
| 138 | |
| 139 | /** |
| 140 | * Convenience function to remove all the data sets from a graph |
| 141 | */ |
| 142 | DygraphLayout.prototype.removeAllDatasets = function() { |
| 143 | delete this.datasets; |
| 144 | this.datasets = new Array(); |
| 145 | }; |
| 146 | |
| 147 | /** |
| 148 | * Change the values of various layout options |
| 149 | * @param {Object} new_options an associative array of new properties |
| 150 | */ |
| 151 | DygraphLayout.prototype.updateOptions = function(new_options) { |
| 152 | MochiKit.Base.update(this.options, new_options ? new_options : {}); |
| 153 | }; |
| 154 | |
| 155 | // Subclass PlotKit.CanvasRenderer to add: |
| 156 | // 1. X/Y grid overlay |
| 157 | // 2. Ability to draw error bars (if required) |
| 158 | |
| 159 | /** |
| 160 | * Sets some PlotKit.CanvasRenderer options |
| 161 | * @param {Object} element The canvas to attach to |
| 162 | * @param {Layout} layout The DygraphLayout object for this graph. |
| 163 | * @param {Object} options Options to pass on to CanvasRenderer |
| 164 | */ |
| 165 | DygraphCanvasRenderer = function(dygraph, element, layout, options) { |
| 166 | // TODO(danvk): remove options, just use dygraph.attr_. |
| 167 | PlotKit.CanvasRenderer.call(this, element, layout, options); |
| 168 | this.dygraph_ = dygraph; |
| 169 | this.options.drawYGrid = true; |
| 170 | this.options.drawXGrid = true; |
| 171 | this.options.gridLineColor = MochiKit.Color.Color.grayColor(); |
| 172 | MochiKit.Base.update(this.options, options); |
| 173 | |
| 174 | // TODO(danvk) This shouldn't be necessary: effects should be overlaid |
| 175 | this.options.drawBackground = false; |
| 176 | }; |
| 177 | DygraphCanvasRenderer.prototype = new PlotKit.CanvasRenderer(); |
| 178 | |
| 179 | /** |
| 180 | * Draw an X/Y grid on top of the existing plot |
| 181 | */ |
| 182 | DygraphCanvasRenderer.prototype.render = function() { |
| 183 | // Draw the new X/Y grid |
| 184 | var ctx = this.element.getContext("2d"); |
| 185 | if (this.options.drawYGrid) { |
| 186 | var ticks = this.layout.yticks; |
| 187 | ctx.save(); |
| 188 | ctx.strokeStyle = this.options.gridLineColor.toRGBString(); |
| 189 | ctx.lineWidth = this.options.axisLineWidth; |
| 190 | for (var i = 0; i < ticks.length; i++) { |
| 191 | var x = this.area.x; |
| 192 | var y = this.area.y + ticks[i][0] * this.area.h; |
| 193 | ctx.beginPath(); |
| 194 | ctx.moveTo(x, y); |
| 195 | ctx.lineTo(x + this.area.w, y); |
| 196 | ctx.closePath(); |
| 197 | ctx.stroke(); |
| 198 | } |
| 199 | } |
| 200 | |
| 201 | if (this.options.drawXGrid) { |
| 202 | var ticks = this.layout.xticks; |
| 203 | ctx.save(); |
| 204 | ctx.strokeStyle = this.options.gridLineColor.toRGBString(); |
| 205 | ctx.lineWidth = this.options.axisLineWidth; |
| 206 | for (var i=0; i<ticks.length; i++) { |
| 207 | var x = this.area.x + ticks[i][0] * this.area.w; |
| 208 | var y = this.area.y + this.area.h; |
| 209 | ctx.beginPath(); |
| 210 | ctx.moveTo(x, y); |
| 211 | ctx.lineTo(x, this.area.y); |
| 212 | ctx.closePath(); |
| 213 | ctx.stroke(); |
| 214 | } |
| 215 | } |
| 216 | |
| 217 | // Do the ordinary rendering, as before |
| 218 | // TODO(danvk) Call super.render() |
| 219 | this._renderLineChart(); |
| 220 | this._renderLineAxis(); |
| 221 | }; |
| 222 | |
| 223 | /** |
| 224 | * Overrides the CanvasRenderer method to draw error bars |
| 225 | */ |
| 226 | DygraphCanvasRenderer.prototype._renderLineChart = function() { |
| 227 | var context = this.element.getContext("2d"); |
| 228 | var colorCount = this.options.colorScheme.length; |
| 229 | var colorScheme = this.options.colorScheme; |
| 230 | var setNames = MochiKit.Base.keys(this.layout.datasets); |
| 231 | var errorBars = this.layout.options.errorBars; |
| 232 | var setCount = setNames.length; |
| 233 | var bind = MochiKit.Base.bind; |
| 234 | var partial = MochiKit.Base.partial; |
| 235 | |
| 236 | //Update Points |
| 237 | var updatePoint = function(point) { |
| 238 | point.canvasx = this.area.w * point.x + this.area.x; |
| 239 | point.canvasy = this.area.h * point.y + this.area.y; |
| 240 | } |
| 241 | MochiKit.Iter.forEach(this.layout.points, updatePoint, this); |
| 242 | |
| 243 | // create paths |
| 244 | var isOK = function(x) { return x && !isNaN(x); }; |
| 245 | var makePath = function(ctx) { |
| 246 | for (var i = 0; i < setCount; i++) { |
| 247 | var setName = setNames[i]; |
| 248 | var color = colorScheme[i%colorCount]; |
| 249 | var strokeX = this.options.strokeColorTransform; |
| 250 | |
| 251 | // setup graphics context |
| 252 | context.save(); |
| 253 | context.strokeStyle = color.toRGBString(); |
| 254 | context.lineWidth = this.options.strokeWidth; |
| 255 | var point = this.layout.points[0]; |
| 256 | var pointSize = this.dygraph_.attr_("pointSize"); |
| 257 | var prevX = null, prevY = null; |
| 258 | var drawPoints = this.dygraph_.attr_("drawPoints"); |
| 259 | var points = this.layout.points; |
| 260 | for (var j = 0; j < points.length; j++) { |
| 261 | var point = points[j]; |
| 262 | if (point.name == setName) { |
| 263 | if (!isOK(point.canvasy)) { |
| 264 | // this will make us move to the next point, not draw a line to it. |
| 265 | prevX = prevY = null; |
| 266 | } else { |
| 267 | // A point is "isolated" if it is non-null but both the previous |
| 268 | // and next points are null. |
| 269 | var isIsolated = (!prevX && (j == points.length - 1 || |
| 270 | !isOK(points[j+1].canvasy))); |
| 271 | |
| 272 | if (!prevX) { |
| 273 | prevX = point.canvasx; |
| 274 | prevY = point.canvasy; |
| 275 | } else { |
| 276 | ctx.beginPath(); |
| 277 | ctx.moveTo(prevX, prevY); |
| 278 | prevX = point.canvasx; |
| 279 | prevY = point.canvasy; |
| 280 | ctx.lineTo(prevX, prevY); |
| 281 | ctx.stroke(); |
| 282 | } |
| 283 | |
| 284 | if (drawPoints || isIsolated) { |
| 285 | ctx.beginPath(); |
| 286 | ctx.fillStyle = color.toRGBString(); |
| 287 | ctx.arc(point.canvasx, point.canvasy, pointSize, 0, 360, false); |
| 288 | ctx.fill(); |
| 289 | } |
| 290 | } |
| 291 | } |
| 292 | } |
| 293 | } |
| 294 | }; |
| 295 | |
| 296 | var makeErrorBars = function(ctx) { |
| 297 | for (var i = 0; i < setCount; i++) { |
| 298 | var setName = setNames[i]; |
| 299 | var color = colorScheme[i % colorCount]; |
| 300 | var strokeX = this.options.strokeColorTransform; |
| 301 | |
| 302 | // setup graphics context |
| 303 | context.save(); |
| 304 | context.strokeStyle = color.toRGBString(); |
| 305 | context.lineWidth = this.options.strokeWidth; |
| 306 | var prevX = -1; |
| 307 | var prevYs = [-1, -1]; |
| 308 | var count = 0; |
| 309 | var yscale = this.layout.yscale; |
| 310 | var errorTrapezoid = function(ctx_,point) { |
| 311 | count++; |
| 312 | if (point.name == setName) { |
| 313 | if (!point.y || isNaN(point.y)) { |
| 314 | prevX = -1; |
| 315 | return; |
| 316 | } |
| 317 | var newYs = [ point.y - point.errorPlus * yscale, |
| 318 | point.y + point.errorMinus * yscale ]; |
| 319 | newYs[0] = this.area.h * newYs[0] + this.area.y; |
| 320 | newYs[1] = this.area.h * newYs[1] + this.area.y; |
| 321 | if (prevX >= 0) { |
| 322 | ctx_.moveTo(prevX, prevYs[0]); |
| 323 | ctx_.lineTo(point.canvasx, newYs[0]); |
| 324 | ctx_.lineTo(point.canvasx, newYs[1]); |
| 325 | ctx_.lineTo(prevX, prevYs[1]); |
| 326 | ctx_.closePath(); |
| 327 | } |
| 328 | prevYs[0] = newYs[0]; |
| 329 | prevYs[1] = newYs[1]; |
| 330 | prevX = point.canvasx; |
| 331 | } |
| 332 | }; |
| 333 | // should be same color as the lines |
| 334 | var err_color = color.colorWithAlpha(0.15); |
| 335 | ctx.fillStyle = err_color.toRGBString(); |
| 336 | ctx.beginPath(); |
| 337 | MochiKit.Iter.forEach(this.layout.points, partial(errorTrapezoid, ctx), this); |
| 338 | ctx.fill(); |
| 339 | } |
| 340 | }; |
| 341 | |
| 342 | if (errorBars) |
| 343 | bind(makeErrorBars, this)(context); |
| 344 | bind(makePath, this)(context); |
| 345 | context.restore(); |
| 346 | }; |