/**
* @fileoverview Based on PlotKit, but modified to meet the needs of dygraphs.
* In particular, support for:
- * - grid overlays
+ * - grid overlays
* - error bars
* - dygraphs attribute system
*/
this.options = {}; // TODO(danvk): remove, use attr_ instead.
Dygraph.update(this.options, options ? options : {});
this.datasets = new Array();
- this.annotations = new Array()
+ this.annotations = new Array();
};
DygraphLayout.prototype.attr_ = function(name) {
DygraphLayout.prototype.setAnnotations = function(ann) {
// The Dygraph object's annotations aren't parsed. We parse them here and
- // save a copy.
- var parse = this.attr_('xValueParser');
+ // save a copy. If there is no parser, then the user must be using raw format.
+ this.annotations = [];
+ var parse = this.attr_('xValueParser') || function(x) { return x; };
for (var i = 0; i < ann.length; i++) {
var a = {};
if (!ann[i].xval && !ann[i].x) {
for (var name in this.datasets) {
if (!this.datasets.hasOwnProperty(name)) continue;
var series = this.datasets[name];
- var x1 = series[0][0];
- if (!this.minxval || x1 < this.minxval) this.minxval = x1;
-
- var x2 = series[series.length - 1][0];
- if (!this.maxxval || x2 > this.maxxval) this.maxxval = x2;
+ if (series.length > 1) {
+ var x1 = series[0][0];
+ if (!this.minxval || x1 < this.minxval) this.minxval = x1;
+
+ var x2 = series[series.length - 1][0];
+ if (!this.maxxval || x2 > this.maxxval) this.maxxval = x2;
+ }
}
}
this.xrange = this.maxxval - this.minxval;
for (var i = 0; i < this.options.yAxes.length; i++) {
var axis = this.options.yAxes[i];
- axis.minyval = axis.valueRange[0];
- axis.maxyval = axis.valueRange[1];
+ axis.minyval = axis.computedValueRange[0];
+ axis.maxyval = axis.computedValueRange[1];
axis.yrange = axis.maxyval - axis.minyval;
axis.yscale = (axis.yrange != 0 ? 1.0 / axis.yrange : 1.0);
+
+ if (axis.g.attr_("logscale")) {
+ axis.ylogrange = Dygraph.log10(axis.maxyval) - Dygraph.log10(axis.minyval);
+ axis.ylogscale = (axis.ylogrange != 0 ? 1.0 / axis.ylogrange : 1.0);
+ if (!isFinite(axis.ylogrange) || isNaN(axis.ylogrange)) {
+ axis.g.error('axis ' + i + ' of graph at ' + axis.g +
+ ' can\'t be displayed in log scale for range [' +
+ axis.minyval + ' - ' + axis.maxyval + ']');
+ }
+ }
}
};
for (var j = 0; j < dataset.length; j++) {
var item = dataset[j];
+
+ var yval;
+ if (axis.logscale) {
+ yval = 1.0 - ((Dygraph.log10(parseFloat(item[1])) - Dygraph.log10(axis.minyval)) * axis.ylogscale); // really should just be yscale.
+ } else {
+ yval = 1.0 - ((parseFloat(item[1]) - axis.minyval) * axis.yscale);
+ }
var point = {
// TODO(danvk): here
x: ((parseFloat(item[0]) - this.minxval) * this.xscale),
- y: 1.0 - ((parseFloat(item[1]) - axis.minyval) * axis.yscale),
+ y: yval,
xval: parseFloat(item[0]),
yval: parseFloat(item[1]),
name: setName
};
- // limit the x, y values so they do not overdraw
- if (point.y <= 0.0) {
- point.y = 0.0;
- }
- if (point.y >= 1.0) {
- point.y = 1.0;
- }
this.points.push(point);
}
}
for (var j = 0; j < axis.ticks.length; j++) {
var tick = axis.ticks[j];
var label = tick.label;
- var pos = 1.0 - (axis.yscale * (tick.v - axis.minyval));
+ var pos = this.dygraph_.toPercentYCoord(tick.v, i);
if ((pos >= 0.0) && (pos <= 1.0)) {
this.yticks.push([i, pos, label]);
}
Dygraph.update(this.options, new_options ? new_options : {});
};
+/**
+ * Return a copy of the point at the indicated index, with its yval unstacked.
+ * @param int index of point in layout_.points
+ */
+DygraphLayout.prototype.unstackPointAtIndex = function(idx) {
+ var point = this.points[idx];
+
+ // Clone the point since we modify it
+ var unstackedPoint = {};
+ for (var i in point) {
+ unstackedPoint[i] = point[i];
+ }
+
+ if (!this.attr_("stackedGraph")) {
+ return unstackedPoint;
+ }
+
+ // The unstacked yval is equal to the current yval minus the yval of the
+ // next point at the same xval.
+ for (var i = idx+1; i < this.points.length; i++) {
+ if (this.points[i].xval == point.xval) {
+ unstackedPoint.yval -= this.points[i].yval;
+ break;
+ }
+ }
+
+ return unstackedPoint;
+}
+
// Subclass PlotKit.CanvasRenderer to add:
// 1. X/Y grid overlay
// 2. Ability to draw error bars (if required)
this.area.h = this.height - this.options.axisLabelFontSize -
2 * this.options.axisTickSize;
+ // Shrink the drawing area to accomodate additional y-axes.
+ if (this.dygraph_.numAxes() == 2) {
+ // TODO(danvk): per-axis setting.
+ this.area.w -= (this.options.yAxisLabelWidth + 2 * this.options.axisTickSize);
+ } else if (this.dygraph_.numAxes() > 2) {
+ this.dygraph_.error("Only two y-axes are supported at this time. (Trying " +
+ "to use " + this.dygraph_.numAxes() + ")");
+ }
+
this.container.style.position = "relative";
this.container.style.width = this.width + "px";
+
+ // Set up a clipping area for the canvas (and the interaction canvas).
+ // This ensures that we don't overdraw.
+ var ctx = this.dygraph_.canvas_.getContext("2d");
+ ctx.beginPath();
+ ctx.rect(this.area.x, this.area.y, this.area.w, this.area.h);
+ ctx.clip();
+
+ ctx = this.dygraph_.hidden_.getContext("2d");
+ ctx.beginPath();
+ ctx.rect(this.area.x, this.area.y, this.area.w, this.area.h);
+ ctx.clip();
+};
+
+DygraphCanvasRenderer.prototype.attr_ = function(x) {
+ return this.dygraph_.attr_(x);
};
DygraphCanvasRenderer.prototype.clear = function() {
for (var i = 0; i < this.xlabels.length; i++) {
var el = this.xlabels[i];
- el.parentNode.removeChild(el);
+ if (el.parentNode) el.parentNode.removeChild(el);
}
for (var i = 0; i < this.ylabels.length; i++) {
var el = this.ylabels[i];
- el.parentNode.removeChild(el);
+ if (el.parentNode) el.parentNode.removeChild(el);
}
for (var i = 0; i < this.annotations.length; i++) {
var el = this.annotations[i];
- el.parentNode.removeChild(el);
+ if (el.parentNode) el.parentNode.removeChild(el);
}
this.xlabels = new Array();
this.ylabels = new Array();
* Draw an X/Y grid on top of the existing plot
*/
DygraphCanvasRenderer.prototype.render = function() {
- // Shrink the drawing area to accomodate additional y-axes.
- if (this.layout.options.yAxes.length == 2) {
- // TODO(danvk): per-axis setting.
- this.area.w -= (this.options.yAxisLabelWidth + 2 * this.options.axisTickSize);
- } else if (this.layout.options.yAxes.length > 2) {
- this.dygraph_.error("Only two y-axes are supported at this time. (Trying " +
- "to use " + this.layout.yAxes.length + ")");
- }
-
- // Draw the new X/Y grid
+ // Draw the new X/Y grid. Lines appear crisper when pixels are rounded to
+ // half-integers. This prevents them from drawing in two rows/cols.
var ctx = this.element.getContext("2d");
+ function halfUp(x){return Math.round(x)+0.5};
+ function halfDown(y){return Math.round(y)-0.5};
if (this.options.underlayCallback) {
- this.options.underlayCallback(ctx, this.area, this.layout, this.dygraph_);
+ // NOTE: we pass the dygraph object to this callback twice to avoid breaking
+ // users who expect a deprecated form of this callback.
+ this.options.underlayCallback(ctx, this.area, this.dygraph_, this.dygraph_);
}
if (this.options.drawYGrid) {
ctx.strokeStyle = this.options.gridLineColor;
ctx.lineWidth = this.options.axisLineWidth;
for (var i = 0; i < ticks.length; i++) {
- if (ticks[i][0] != 0) continue; // TODO(danvk): per-axis property
- var x = this.area.x;
- var y = this.area.y + ticks[i][1] * this.area.h;
+ // TODO(danvk): allow secondary axes to draw a grid, too.
+ if (ticks[i][0] != 0) continue;
+ var x = halfUp(this.area.x);
+ var y = halfDown(this.area.y + ticks[i][1] * this.area.h);
ctx.beginPath();
ctx.moveTo(x, y);
ctx.lineTo(x + this.area.w, y);
ctx.strokeStyle = this.options.gridLineColor;
ctx.lineWidth = this.options.axisLineWidth;
for (var i=0; i<ticks.length; i++) {
- var x = this.area.x + ticks[i][1] * this.area.w;
- var y = this.area.y + this.area.h;
+ var x = halfUp(this.area.x + ticks[i][0] * this.area.w);
+ var y = halfDown(this.area.y + this.area.h);
ctx.beginPath();
ctx.moveTo(x, y);
ctx.lineTo(x, this.area.y);
if (!this.options.drawXAxis && !this.options.drawYAxis)
return;
+ // Round pixels to half-integer boundaries for crisper drawing.
+ function halfUp(x){return Math.round(x)+0.5};
+ function halfDown(y){return Math.round(y)-0.5};
+
var context = this.element.getContext("2d");
var labelStyle = {
var tick = this.layout.yticks[i];
if (typeof(tick) == "function") return;
var x = this.area.x;
- if (tick[0] == 1) {
- x = this.area.x + this.area.w - labelStyle.width;
+ var sgn = 1;
+ if (tick[0] == 1) { // right-side y-axis
+ x = this.area.x + this.area.w;
+ sgn = -1;
}
var y = this.area.y + tick[1] * this.area.h;
context.beginPath();
- context.moveTo(x, y);
- context.lineTo(x - this.options.axisTickSize, y);
+ context.moveTo(halfUp(x), halfDown(y));
+ context.lineTo(halfUp(x - sgn * this.options.axisTickSize), halfDown(y));
context.closePath();
context.stroke();
}
}
+ // draw a vertical line on the left to separate the chart from the labels.
context.beginPath();
- context.moveTo(this.area.x, this.area.y);
- context.lineTo(this.area.x, this.area.y + this.area.h);
+ context.moveTo(halfUp(this.area.x), halfDown(this.area.y));
+ context.lineTo(halfUp(this.area.x), halfDown(this.area.y + this.area.h));
context.closePath();
context.stroke();
+
+ // if there's a secondary y-axis, draw a vertical line for that, too.
+ if (this.dygraph_.numAxes() == 2) {
+ context.beginPath();
+ context.moveTo(halfDown(this.area.x + this.area.w), halfDown(this.area.y));
+ context.lineTo(halfDown(this.area.x + this.area.w), halfDown(this.area.y + this.area.h));
+ context.closePath();
+ context.stroke();
+ }
}
if (this.options.drawXAxis) {
var x = this.area.x + tick[0] * this.area.w;
var y = this.area.y + this.area.h;
context.beginPath();
- context.moveTo(x, y);
- context.lineTo(x, y + this.options.axisTickSize);
+ context.moveTo(halfUp(x), halfDown(y));
+ context.lineTo(halfUp(x), halfDown(y + this.options.axisTickSize));
context.closePath();
context.stroke();
}
context.beginPath();
- context.moveTo(this.area.x, this.area.y + this.area.h);
- context.lineTo(this.area.x + this.area.w, this.area.y + this.area.h);
+ context.moveTo(halfUp(this.area.x), halfDown(this.area.y + this.area.h));
+ context.lineTo(halfUp(this.area.x + this.area.w), halfDown(this.area.y + this.area.h));
context.closePath();
context.stroke();
}
* Overrides the CanvasRenderer method to draw error bars
*/
DygraphCanvasRenderer.prototype._renderLineChart = function() {
+ // TODO(danvk): use this.attr_ for many of these.
var context = this.element.getContext("2d");
var colorCount = this.options.colorScheme.length;
var colorScheme = this.options.colorScheme;
var fillAlpha = this.options.fillAlpha;
var errorBars = this.layout.options.errorBars;
- var fillGraph = this.layout.options.fillGraph;
+ var fillGraph = this.attr_("fillGraph");
var stackedGraph = this.layout.options.stackedGraph;
var stepPlot = this.layout.options.stepPlot;
}
// create paths
- var isOK = function(x) { return x && !isNaN(x); };
-
var ctx = context;
if (errorBars) {
if (fillGraph) {
for (var j = 0; j < this.layout.points.length; j++) {
var point = this.layout.points[j];
if (point.name == setName) {
- if (!isOK(point.y)) {
+ if (!Dygraph.isOK(point.y)) {
prevX = NaN;
continue;
}
for (var j = 0; j < this.layout.points.length; j++) {
var point = this.layout.points[j];
if (point.name == setName) {
- if (!isOK(point.y)) {
+ if (!Dygraph.isOK(point.y)) {
prevX = NaN;
continue;
}
for (var j = 0; j < points.length; j++) {
var point = points[j];
if (point.name == setName) {
- if (!isOK(point.canvasy)) {
+ if (!Dygraph.isOK(point.canvasy)) {
+ if (stepPlot && prevX != null) {
+ // Draw a horizontal line to the start of the missing data
+ ctx.beginPath();
+ ctx.strokeStyle = color;
+ ctx.lineWidth = this.options.strokeWidth;
+ ctx.moveTo(prevX, prevY);
+ ctx.lineTo(point.canvasx, prevY);
+ ctx.stroke();
+ }
// this will make us move to the next point, not draw a line to it.
prevX = prevY = null;
} else {
// A point is "isolated" if it is non-null but both the previous
// and next points are null.
var isIsolated = (!prevX && (j == points.length - 1 ||
- !isOK(points[j+1].canvasy)));
+ !Dygraph.isOK(points[j+1].canvasy)));
if (!prevX) {
prevX = point.canvasx;