Dygraph.DEFAULT_HEIGHT = 320;
Dygraph.AXIS_LINE_WIDTH = 0.3;
+Dygraph.LOG_SCALE = 10;
+Dygraph.LOG_BASE_E_OF_TEN = Math.log(Dygraph.LOG_SCALE);
+Dygraph.log10 = function(x) {
+ return Math.log(x) / Dygraph.LOG_BASE_E_OF_TEN;
+}
// Default attribute values.
Dygraph.DEFAULT_ATTRS = {
labelsKMG2: false,
showLabelsOnHighlight: true,
- yValueFormatter: function(x, opt_numDigits) {
- return x.toPrecision(opt_numDigits || 2);
- },
+ yValueFormatter: function(x) { return Dygraph.round_(x, 2); },
strokeWidth: 1.0,
this.wilsonInterval_ = attrs.wilsonInterval || true;
this.is_initial_draw_ = true;
this.annotations_ = [];
- this.numDigits_ = 2;
// Clear the div. This ensure that, if multiple dygraphs are passed the same
// div, then only one will be drawn.
/**
* Returns the current rolling period, as set by the user or an option.
- * @return {Number} The number of points in the rolling window
+ * @return {Number} The number of days in the rolling window
*/
Dygraph.prototype.rollPeriod = function() {
return this.rollPeriod_;
* If specified, do this conversion for the coordinate system of a particular
* axis. Uses the first axis by default.
* Returns a two-element array: [X, Y]
+ *
+ * Note: use toDomXCoord instead of toDomCoords(x, null) and use toDomYCoord
+ * instead of toDomCoords(null, y, axis).
*/
Dygraph.prototype.toDomCoords = function(x, y, axis) {
- var ret = [null, null];
+ return [ this.toDomXCoord(x), this.toDomYCoord(y, axis) ];
+};
+
+/**
+ * Convert from data x coordinates to canvas/div X coordinate.
+ * If specified, do this conversion for the coordinate system of a particular
+ * axis. Uses the first axis by default.
+ * returns a single value or null if x is null.
+ */
+Dygraph.prototype.toDomXCoord = function(x) {
+ if (x == null) {
+ return null;
+ };
+
var area = this.plotter_.area;
- if (x !== null) {
- var xRange = this.xAxisRange();
- ret[0] = area.x + (x - xRange[0]) / (xRange[1] - xRange[0]) * area.w;
- }
+ var xRange = this.xAxisRange();
+ return area.x + (x - xRange[0]) / (xRange[1] - xRange[0]) * area.w;
+}
- if (y !== null) {
- var yRange = this.yAxisRange(axis);
- ret[1] = area.y + (yRange[1] - y) / (yRange[1] - yRange[0]) * area.h;
- }
+/**
+ * Convert from data x coordinates to canvas/div Y coordinate and optional
+ * axis. Uses the first axis by default.
+ *
+ * returns a single value or null if y is null.
+ */
+Dygraph.prototype.toDomYCoord = function(y, axis) {
+ var pct = this.toPercentYCoord(y, axis);
- return ret;
-};
+ if (pct == null) {
+ return null;
+ }
+ return area.y + pct * area.h;
+}
/**
* Convert from canvas/div coords to data coordinates.
* If specified, do this conversion for the coordinate system of a particular
* axis. Uses the first axis by default.
- * Returns a two-element array: [X, Y]
+ * Returns a two-element array: [X, Y].
+ *
+ * Note: use toDataXCoord instead of toDataCoords(x, null) and use toDataYCoord
+ * instead of toDataCoords(null, y, axis).
*/
Dygraph.prototype.toDataCoords = function(x, y, axis) {
- var ret = [null, null];
+ return [ this.toDataXCoord(x), this.toDataYCoord(y, axis) ];
+};
+
+/**
+ * Convert from canvas/div x coordinate to data coordinate.
+ *
+ * If x is null, this returns null.
+ */
+Dygraph.prototype.toDataXCoord = function(x) {
+ if (x == null) {
+ return null;
+ }
+
var area = this.plotter_.area;
- if (x !== null) {
- var xRange = this.xAxisRange();
- ret[0] = xRange[0] + (x - area.x) / area.w * (xRange[1] - xRange[0]);
+ var xRange = this.xAxisRange();
+ return xRange[0] + (x - area.x) / area.w * (xRange[1] - xRange[0]);
+};
+
+/**
+ * Convert from canvas/div y coord to value.
+ *
+ * If y is null, this returns null.
+ * if axis is null, this uses the first axis.
+ */
+Dygraph.prototype.toDataYCoord = function(y, axis) {
+ if (y == null) {
+ return null;
}
- if (y !== null) {
- var yRange = this.yAxisRange(axis);
- ret[1] = yRange[0] + (area.h - y) / area.h * (yRange[1] - yRange[0]);
+ var area = this.plotter_.area;
+ var yRange = this.yAxisRange(axis);
+
+ if (!this.attr_("logscale")) {
+ return yRange[0] + (area.h - y) / area.h * (yRange[1] - yRange[0]);
+ } else {
+ // Computing the inverse of toDomCoord.
+ var pct = (y - area.y) / area.h
+
+ // Computing the inverse of toPercentYCoord. The function was arrived at with
+ // the following steps:
+ //
+ // Original calcuation:
+ // pct = (logr1 - Dygraph.log10(y)) / (logr1 - Dygraph.log10(yRange[0]));
+ //
+ // Move denominator to both sides:
+ // pct * (logr1 - Dygraph.log10(yRange[0])) = logr1 - Dygraph.log10(y);
+ //
+ // subtract logr1, and take the negative value.
+ // logr1 - (pct * (logr1 - Dygraph.log10(yRange[0]))) = Dygraph.log10(y);
+ //
+ // Swap both sides of the equation, and we can compute the log of the
+ // return value. Which means we just need to use that as the exponent in
+ // e^exponent.
+ // Dygraph.log10(y) = logr1 - (pct * (logr1 - Dygraph.log10(yRange[0])));
+
+ var logr1 = Dygraph.log10(yRange[1]);
+ var exponent = logr1 - (pct * (logr1 - Dygraph.log10(yRange[0])));
+ var value = Math.pow(Dygraph.LOG_SCALE, exponent);
+ return value;
+ }
+};
+
+/**
+ * Converts a y for an axis to a percentage from the top to the
+ * bottom of the div.
+ *
+ * If the coordinate represents a value visible on the canvas, then
+ * the value will be between 0 and 1, where 0 is the top of the canvas.
+ * However, this method will return values outside the range, as
+ * values can fall outside the canvas.
+ *
+ * If y is null, this returns null.
+ * if axis is null, this uses the first axis.
+ */
+Dygraph.prototype.toPercentYCoord = function(y, axis) {
+ if (y == null) {
+ return null;
}
- return ret;
-};
+ var area = this.plotter_.area;
+ var yRange = this.yAxisRange(axis);
+
+ var pct;
+ if (!this.attr_("logscale")) {
+ // yrange[1] - y is unit distance from the bottom.
+ // yrange[1] - yrange[0] is the scale of the range.
+ // (yRange[1] - y) / (yRange[1] - yRange[0]) is the % from the bottom.
+ pct = (yRange[1] - y) / (yRange[1] - yRange[0]);
+ } else {
+ var logr1 = Dygraph.log10(yRange[1]);
+ pct = (logr1 - Dygraph.log10(y)) / (logr1 - Dygraph.log10(yRange[0]));
+ }
+ return pct;
+}
/**
* Returns the number of columns (including the independent variable).
// panning behavior.
//
Dygraph.startPan = function(event, g, context) {
- // have to be zoomed in to pan.
- // TODO(konigsberg): Let's loosen this zoom-to-pan restriction, also
- // perhaps create panning boundaries? A more flexible pan would make it,
- // ahem, 'pan-useful'.
- var zoomedY = false;
- for (var i = 0; i < g.axes_.length; i++) {
- if (g.axes_[i].valueWindow || g.axes_[i].valueRange) {
- zoomedY = true;
- break;
- }
- }
- if (!g.dateWindow_ && !zoomedY) return;
-
context.isPanning = true;
var xRange = g.xAxisRange();
context.dateRange = xRange[1] - xRange[0];
var axis = g.axes_[i];
var yRange = g.yAxisRange(i);
axis.dragValueRange = yRange[1] - yRange[0];
- var r = g.toDataCoords(null, context.dragStartY, i);
- axis.draggingValue = r[1];
+ axis.draggingValue = g.toDataYCoord(context.dragStartY, i);
if (axis.valueWindow || axis.valueRange) context.is2DPan = true;
}
// y-axis scaling is automatic unless this is a full 2D pan.
if (context.is2DPan) {
// Adjust each axis appropriately.
+ // NOTE(konigsberg): I don't think this computation for y_frac is correct.
+ // I think it doesn't take into account the display of the x axis.
+ // See, when I tested this with console.log(y_frac), and move the mouse
+ // cursor to the botom, the largest y_frac was 0.94, and not 1.0. That
+ // could also explain why panning tends to start with a small jumpy shift.
var y_frac = context.dragEndY / g.height_;
+
for (var i = 0; i < g.axes_.length; i++) {
var axis = g.axes_[i];
var maxValue = axis.draggingValue + y_frac * axis.dragValueRange;
var minValue = maxValue - axis.dragValueRange;
+ console.log(axis.draggingValue, axis.dragValueRange, minValue, maxValue, y_frac);
axis.valueWindow = [ minValue, maxValue ];
}
}
Dygraph.prototype.doZoomX_ = function(lowX, highX) {
// Find the earliest and latest dates contained in this canvasx range.
// Convert the call to date ranges of the raw data.
- var r = this.toDataCoords(lowX, null);
- var minDate = r[0];
- r = this.toDataCoords(highX, null);
- var maxDate = r[0];
+ var minDate = this.toDataXCoord(lowX);
+ var maxDate = this.toDataXCoord(highX);
this.doZoomXDates_(minDate, maxDate);
};
// coordinates increase as you go up the screen.
var valueRanges = [];
for (var i = 0; i < this.axes_.length; i++) {
- var hi = this.toDataCoords(null, lowY, i);
- var low = this.toDataCoords(null, highY, i);
- this.axes_[i].valueWindow = [low[1], hi[1]];
- valueRanges.push([low[1], hi[1]]);
+ var hi = this.toDataYCoord(lowY, i);
+ var low = this.toDataYCoord(highY, i);
+ this.axes_[i].valueWindow = [low, hi];
+ valueRanges.push([low, hi]);
}
this.drawGraph_();
}
var point = this.selPoints_[i];
var c = new RGBColor(this.plotter_.colors[point.name]);
- var yval = fmtFunc(point.yval, this.numDigits_ + 1); // In tenths.
+ var yval = fmtFunc(point.yval);
replace += " <b><font color='" + c.toHex() + "'>"
+ point.name + "</font></b>:"
+ yval;
};
/**
+ * Round a number to the specified number of digits past the decimal point.
+ * @param {Number} num The number to round
+ * @param {Number} places The number of decimals to which to round
+ * @return {Number} The rounded number
+ * @private
+ */
+Dygraph.round_ = function(num, places) {
+ var shift = Math.pow(10, places);
+ return Math.round(num * shift)/shift;
+};
+
+/**
* Fires when there's data available to be graphed.
* @param {String} data Raw CSV data to be plotted
* @private
endDate = this.rawData_[this.rawData_.length - 1][0];
}
- var ret = this.attr_('xTicker')(startDate, endDate, this);
- if (ret.ticks !== undefined) { // Used numericTicks()?
- this.layout_.updateOptions({xTicks: ret.ticks});
- } else { // Used dateTicker() instead.
- this.layout_.updateOptions({xTicks: ret});
- }
+ var xTicks = this.attr_('xTicker')(startDate, endDate, this);
+ this.layout_.updateOptions({xTicks: xTicks});
};
// Time granularity enumeration
};
/**
- * Determine the number of significant figures in a Number up to the specified
- * precision. Note that there is no way to determine if a trailing '0' is
- * significant or not, so by convention we return 1 for all of the following
- * inputs: 1, 1.0, 1.00, 1.000 etc.
- * @param {Number} x The input value.
- * @param {Number} opt_maxPrecision Optional maximum precision to consider.
- * Default and maximum allowed value is 13.
- * @return {Number} The number of significant figures which is >= 1.
- */
-Dygraph.significantFigures = function(x, opt_maxPrecision) {
- var precision = Math.max(opt_maxPrecision || 13, 13);
-
- // Convert the number to it's exponential notation form and work backwards,
- // ignoring the 'e+xx' bit. This may seem like a hack, but doing a loop and
- // dividing by 10 leads to roundoff errors. By using toExponential(), we let
- // the JavaScript interpreter handle the low level bits of the Number for us.
- var s = x.toExponential(precision);
- var ePos = s.lastIndexOf('e'); // -1 case handled by return below.
-
- for (var i = ePos - 1; i >= 0; i--) {
- if (s[i] == '.') {
- // Got to the decimal place. We'll call this 1 digit of precision because
- // we can't know for sure how many trailing 0s are significant.
- return 1;
- } else if (s[i] != '0') {
- // Found the first non-zero digit. Return the number of characters
- // except for the '.'.
- return i; // This is i - 1 + 1 (-1 is for '.', +1 is for 0 based index).
- }
- }
-
- // Occurs if toExponential() doesn't return a string containing 'e', which
- // should never happen.
- return 1;
-};
-
-/**
* Add ticks when the x axis has numbers on it (instead of dates)
+ * TODO(konigsberg): Update comment.
+ *
* @param {Number} startDate Start of the date window (millis since epoch)
* @param {Number} endDate End of the date window (millis since epoch)
* @param self
var ticks = [];
if (vals) {
for (var i = 0; i < vals.length; i++) {
- ticks[i] = {v: vals[i]};
+ ticks.push({v: vals[i]});
}
} else {
- // Basic idea:
- // Try labels every 1, 2, 5, 10, 20, 50, 100, etc.
- // Calculate the resulting tick spacing (i.e. this.height_ / nTicks).
- // The first spacing greater than pixelsPerYLabel is what we use.
- // TODO(danvk): version that works on a log scale.
- if (attr("labelsKMG2")) {
- var mults = [1, 2, 4, 8];
+ if (self.attr_("logscale")) {
+ // As opposed to the other ways for computing ticks, we're just going
+ // for nearby values. There's no reasonable way to scale the values
+ // (unless we want to show strings like "log(" + x + ")") in which case
+ // x can be integer values.
+
+ // so compute height / pixelsPerTick and move on.
+ var pixelsPerTick = attr('pixelsPerYLabel');
+ var nTicks = Math.floor(self.height_ / pixelsPerTick);
+ var vv = minV;
+
+ // Construct the set of ticks.
+ for (var i = 0; i < nTicks; i++) {
+ ticks.push( {v: vv} );
+ vv = vv * Dygraph.LOG_SCALE;
+ }
} else {
- var mults = [1, 2, 5];
- }
- var scale, low_val, high_val, nTicks;
- // TODO(danvk): make it possible to set this for x- and y-axes independently.
- var pixelsPerTick = attr('pixelsPerYLabel');
- for (var i = -10; i < 50; i++) {
+ // Basic idea:
+ // Try labels every 1, 2, 5, 10, 20, 50, 100, etc.
+ // Calculate the resulting tick spacing (i.e. this.height_ / nTicks).
+ // The first spacing greater than pixelsPerYLabel is what we use.
+ // TODO(danvk): version that works on a log scale.
if (attr("labelsKMG2")) {
- var base_scale = Math.pow(16, i);
+ var mults = [1, 2, 4, 8];
} else {
- var base_scale = Math.pow(10, i);
+ var mults = [1, 2, 5];
}
- for (var j = 0; j < mults.length; j++) {
- scale = base_scale * mults[j];
- low_val = Math.floor(minV / scale) * scale;
- high_val = Math.ceil(maxV / scale) * scale;
- nTicks = Math.abs(high_val - low_val) / scale;
- var spacing = self.height_ / nTicks;
- // wish I could break out of both loops at once...
+ var scale, low_val, high_val, nTicks;
+ // TODO(danvk): make it possible to set this for x- and y-axes independently.
+ var pixelsPerTick = attr('pixelsPerYLabel');
+ for (var i = -10; i < 50; i++) {
+ if (attr("labelsKMG2")) {
+ var base_scale = Math.pow(16, i);
+ } else {
+ var base_scale = Math.pow(10, i);
+ }
+ for (var j = 0; j < mults.length; j++) {
+ scale = base_scale * mults[j];
+ low_val = Math.floor(minV / scale) * scale;
+ high_val = Math.ceil(maxV / scale) * scale;
+ nTicks = Math.abs(high_val - low_val) / scale;
+ var spacing = self.height_ / nTicks;
+ // wish I could break out of both loops at once...
+ if (spacing > pixelsPerTick) break;
+ }
if (spacing > pixelsPerTick) break;
}
- if (spacing > pixelsPerTick) break;
- }
- // Construct the set of ticks.
- // Allow reverse y-axis if it's explicitly requested.
- if (low_val > high_val) scale *= -1;
- for (var i = 0; i < nTicks; i++) {
- var tickV = low_val + i * scale;
- ticks[i] = {v: tickV};
+ // Construct the set of ticks.
+ // Allow reverse y-axis if it's explicitly requested.
+ if (low_val > high_val) scale *= -1;
+ for (var i = 0; i < nTicks; i++) {
+ var tickV = low_val + i * scale;
+ ticks.push( {v: tickV} );
+ }
}
}
k = 1024;
k_labels = [ "k", "M", "G", "T" ];
}
- var formatter = attr('yAxisLabelFormatter') ?
- attr('yAxisLabelFormatter') : attr('yValueFormatter');
-
- // Determine the number of decimal places needed for the labels below by
- // taking the maximum number of significant figures for any label. We must
- // take the max because we can't tell if trailing 0s are significant.
- var numDigits = 0;
- for (var i = 0; i < ticks.length; i++) {
- var tickV = ticks[i].v;
- numDigits = Math.max(Dygraph.significantFigures(tickV), numDigits);
- }
+ var formatter = attr('yAxisLabelFormatter') ? attr('yAxisLabelFormatter') : attr('yValueFormatter');
for (var i = 0; i < ticks.length; i++) {
var tickV = ticks[i].v;
var absTickV = Math.abs(tickV);
- var label = (formatter !== undefined) ?
- formatter(tickV, numDigits) : tickV.toPrecision(numDigits);
- if (k_labels.length > 0) {
+ var label;
+ if (formatter != undefined) {
+ label = formatter(tickV);
+ } else {
+ label = Dygraph.round_(tickV, 2);
+ }
+ if (k_labels.length) {
// Round up to an appropriate unit.
var n = k*k*k*k;
for (var j = 3; j >= 0; j--, n /= k) {
if (absTickV >= n) {
- label = (tickV / n).toPrecision(numDigits) + k_labels[j];
+ label = Dygraph.round_(tickV / n, 1) + k_labels[j];
break;
}
}
}
ticks[i].label = label;
}
- return {ticks: ticks, numDigits: numDigits};
+ return ticks;
};
// Computes the range of the data series (including confidence intervals).
};
/**
-=======
* Update the graph with new data. This method is called when the viewing area
* has changed. If the underlying data or options have changed, predraw_ will
* be called before drawGraph_ is called.
this.layout_.addDataset(this.attr_("labels")[i], datasets[i]);
}
- this.computeYAxisRanges_(extremes);
- this.layout_.updateOptions( { yAxes: this.axes_,
- seriesToAxisMap: this.seriesToAxisMap_
+ // TODO(danvk): this method doesn't need to return anything.
+ var out = this.computeYAxisRanges_(extremes);
+ var axes = out[0];
+ var seriesToAxisMap = out[1];
+ this.layout_.updateOptions( { yAxes: axes,
+ seriesToAxisMap: seriesToAxisMap
} );
this.addXTicks_();
// Compute extreme values, a span and tick marks for each axis.
for (var i = 0; i < this.axes_.length; i++) {
+ var isLogScale = this.attr_("logscale");
var axis = this.axes_[i];
if (axis.valueWindow) {
// This is only set if the user has zoomed on the y-axis. It is never set
var span = maxY - minY;
// special case: if we have no sense of scale, use +/-10% of the sole value.
if (span == 0) { span = maxY; }
- var maxAxisY = maxY + 0.1 * span;
- var minAxisY = minY - 0.1 * span;
- // Try to include zero and make it minAxisY (or maxAxisY) if it makes sense.
- if (!this.attr_("avoidMinZero")) {
- if (minAxisY < 0 && minY >= 0) minAxisY = 0;
- if (maxAxisY > 0 && maxY <= 0) maxAxisY = 0;
- }
+ var maxAxisY;
+ var minAxisY;
+ if (isLogScale) {
+ var maxAxisY = maxY + 0.1 * span;
+ var minAxisY = minY;
+ } else {
+ var maxAxisY = maxY + 0.1 * span;
+ var minAxisY = minY - 0.1 * span;
+
+ // Try to include zero and make it minAxisY (or maxAxisY) if it makes sense.
+ if (!this.attr_("avoidMinZero")) {
+ if (minAxisY < 0 && minY >= 0) minAxisY = 0;
+ if (maxAxisY > 0 && maxY <= 0) maxAxisY = 0;
+ }
- if (this.attr_("includeZero")) {
- if (maxY < 0) maxAxisY = 0;
- if (minY > 0) minAxisY = 0;
+ if (this.attr_("includeZero")) {
+ if (maxY < 0) maxAxisY = 0;
+ if (minY > 0) minAxisY = 0;
+ }
}
axis.computedValueRange = [minAxisY, maxAxisY];
// primary axis. However, if an axis is specifically marked as having
// independent ticks, then that is permissible as well.
if (i == 0 || axis.independentTicks) {
- var ret =
+ axis.ticks =
Dygraph.numericTicks(axis.computedValueRange[0],
axis.computedValueRange[1],
this,
axis);
- axis.ticks = ret.ticks;
- this.numDigits_ = ret.numDigits;
} else {
var p_axis = this.axes_[0];
var p_ticks = p_axis.ticks;
tick_values.push(y_val);
}
- var ret =
+ axis.ticks =
Dygraph.numericTicks(axis.computedValueRange[0],
axis.computedValueRange[1],
this, axis, tick_values);
- axis.ticks = ret.ticks;
- this.numDigits_ = ret.numDigits;
}
}
+
+ return [this.axes_, this.seriesToAxisMap_];
};
/**
* Note that this is where fractional input (i.e. '5/10') is converted into
* decimal values.
* @param {Array} originalData The data in the appropriate format (see above)
- * @param {Number} rollPeriod The number of points over which to average the
- * data
+ * @param {Number} rollPeriod The number of days over which to average the data
*/
Dygraph.prototype.rollingAverage = function(originalData, rollPeriod) {
if (originalData.length < 2)
}
} else {
// Calculate the rolling average for the first rollPeriod - 1 points where
- // there is not enough data to roll over the full number of points
+ // there is not enough data to roll over the full number of days
var num_init_points = Math.min(rollPeriod - 1, originalData.length - 2);
if (!this.attr_("errorBars")){
if (rollPeriod == 1) {
};
/**
- * Adjusts the number of points in the rolling average. Updates the graph to
+ * Adjusts the number of days in the rolling average. Updates the graph to
* reflect the new averaging period.
- * @param {Number} length Number of points over which to average the data.
+ * @param {Number} length Number of days over which to average the data.
*/
Dygraph.prototype.adjustRoll = function(length) {
this.rollPeriod_ = length;