* middle of the years.
*/
-/*jshint globalstrict: true */
+/*jshint globalstrict:true, sub:true */
/*global Dygraph:false */
"use strict";
+/** @typedef {Array.<{v:number, label:string, label_v:(string|undefined)}>} */
+Dygraph.TickList = undefined; // the ' = undefined' keeps jshint happy.
+
+/** @typedef {function(
+ * number,
+ * number,
+ * number,
+ * function(string):*,
+ * Dygraph=,
+ * Array.<number>=
+ * ): Dygraph.TickList}
+ */
+Dygraph.Ticker = undefined; // the ' = undefined' keeps jshint happy.
+
+/** @type {Dygraph.Ticker} */
Dygraph.numericLinearTicks = function(a, b, pixels, opts, dygraph, vals) {
var nonLogscaleOpts = function(opt) {
if (opt === 'logscale') return false;
return Dygraph.numericTicks(a, b, pixels, nonLogscaleOpts, dygraph, vals);
};
+/** @type {Dygraph.Ticker} */
Dygraph.numericTicks = function(a, b, pixels, opts, dygraph, vals) {
- var pixels_per_tick = opts('pixelsPerLabel');
+ var pixels_per_tick = /** @type{number} */(opts('pixelsPerLabel'));
var ticks = [];
var i, j, tickV, nTicks;
if (vals) {
// The first spacing greater than pixelsPerYLabel is what we use.
// TODO(danvk): version that works on a log scale.
var kmg2 = opts("labelsKMG2");
- var mults;
+ var mults, base;
if (kmg2) {
- mults = [1, 2, 4, 8];
+ mults = [1, 2, 4, 8, 16, 32, 64, 128, 256];
+ base = 16;
} else {
- mults = [1, 2, 5];
+ mults = [1, 2, 5, 10, 20, 50, 100];
+ base = 10;
}
- var scale, low_val, high_val;
- for (i = -10; i < 50; i++) {
- var base_scale;
- if (kmg2) {
- base_scale = Math.pow(16, i);
- } else {
- base_scale = Math.pow(10, i);
- }
- var spacing = 0;
- for (j = 0; j < mults.length; j++) {
- scale = base_scale * mults[j];
- low_val = Math.floor(a / scale) * scale;
- high_val = Math.ceil(b / scale) * scale;
- nTicks = Math.abs(high_val - low_val) / scale;
- spacing = pixels / nTicks;
- // wish I could break out of both loops at once...
- if (spacing > pixels_per_tick) break;
- }
+
+ // Get the maximum number of permitted ticks based on the
+ // graph's pixel size and pixels_per_tick setting.
+ var max_ticks = Math.ceil(pixels / pixels_per_tick);
+
+ // Now calculate the data unit equivalent of this tick spacing.
+ // Use abs() since graphs may have a reversed Y axis.
+ var units_per_tick = Math.abs(b - a) / max_ticks;
+
+ // Based on this, get a starting scale which is the largest
+ // integer power of the chosen base (10 or 16) that still remains
+ // below the requested pixels_per_tick spacing.
+ var base_power = Math.floor(Math.log(units_per_tick) / Math.log(base));
+ var base_scale = Math.pow(base, base_power);
+
+ // Now try multiples of the starting scale until we find one
+ // that results in tick marks spaced sufficiently far apart.
+ // The "mults" array should cover the range 1 .. base^2 to
+ // adjust for rounding and edge effects.
+ var scale, low_val, high_val, spacing;
+ for (j = 0; j < mults.length; j++) {
+ scale = base_scale * mults[j];
+ low_val = Math.floor(a / scale) * scale;
+ high_val = Math.ceil(b / scale) * scale;
+ nTicks = Math.abs(high_val - low_val) / scale;
+ spacing = pixels / nTicks;
if (spacing > pixels_per_tick) break;
}
}
}
- // Add formatted labels to the ticks.
- var k;
- var k_labels = [];
- if (opts("labelsKMB")) {
- k = 1000;
- k_labels = [ "K", "M", "B", "T", "Q" ];
- }
- if (opts("labelsKMG2")) {
- if (k) Dygraph.warn("Setting both labelsKMB and labelsKMG2. Pick one!");
- k = 1024;
- k_labels = [ "k", "M", "G", "T", "P", "E" ];
- }
-
- var formatter = opts('axisLabelFormatter');
+ var formatter = /**@type{AxisLabelFormatter}*/(opts('axisLabelFormatter'));
// Add labels to the ticks.
for (i = 0; i < ticks.length; i++) {
if (ticks[i].label !== undefined) continue; // Use current label.
- tickV = ticks[i].v;
- var absTickV = Math.abs(tickV);
// TODO(danvk): set granularity to something appropriate here.
- var label = formatter(tickV, 0, opts, dygraph);
- if (k_labels.length > 0) {
- // TODO(danvk): should this be integrated into the axisLabelFormatter?
- // Round up to an appropriate unit.
- var n = Math.pow(k, k_labels.length);
- for (j = k_labels.length - 1; j >= 0; j--, n /= k) {
- if (absTickV >= n) {
- label = Dygraph.round_(tickV / n, opts('digitsAfterDecimal')) +
- k_labels[j];
- break;
- }
- }
- }
- ticks[i].label = label;
+ ticks[i].label = formatter(ticks[i].v, 0, opts, dygraph);
}
return ticks;
};
+/** @type {Dygraph.Ticker} */
Dygraph.dateTicker = function(a, b, pixels, opts, dygraph, vals) {
var chosen = Dygraph.pickDateTickGranularity(a, b, pixels, opts);
};
// Time granularity enumeration
+// TODO(danvk): make this an @enum
Dygraph.SECONDLY = 0;
Dygraph.TWO_SECONDLY = 1;
Dygraph.FIVE_SECONDLY = 2;
Dygraph.CENTENNIAL = 20;
Dygraph.NUM_GRANULARITIES = 21;
+/** @type {Array.<number>} */
Dygraph.SHORT_SPACINGS = [];
Dygraph.SHORT_SPACINGS[Dygraph.SECONDLY] = 1000 * 1;
Dygraph.SHORT_SPACINGS[Dygraph.TWO_SECONDLY] = 1000 * 2;
Dygraph.SHORT_SPACINGS[Dygraph.WEEKLY] = 1000 * 604800;
/**
- * @private
* This is a list of human-friendly values at which to show tick marks on a log
* scale. It is k * 10^n, where k=1..9 and n=-39..+39, so:
* ..., 1, 2, 3, 4, 5, ..., 9, 10, 20, 30, ..., 90, 100, 200, 300, ...
* NOTE: this assumes that Dygraph.LOG_SCALE = 10.
+ * @type {Array.<number>}
*/
Dygraph.PREFERRED_LOG_TICK_VALUES = function() {
var vals = [];
/**
* Determine the correct granularity of ticks on a date axis.
*
- * @param {Number} a Left edge of the chart (ms)
- * @param {Number} b Right edge of the chart (ms)
- * @param {Number} pixels Size of the chart in the relevant dimension (width).
- * @param {Function} opts Function mapping from option name -> value.
- * @return {Number} The appropriate axis granularity for this chart. See the
- * enumeration of possible values in dygraph-tickers.js.
+ * @param {number} a Left edge of the chart (ms)
+ * @param {number} b Right edge of the chart (ms)
+ * @param {number} pixels Size of the chart in the relevant dimension (width).
+ * @param {function(string):*} opts Function mapping from option name ->
+ * value.
+ * @return {number} The appropriate axis granularity for this chart. See the
+ * enumeration of possible values in dygraph-tickers.js.
*/
Dygraph.pickDateTickGranularity = function(a, b, pixels, opts) {
- var pixels_per_tick = opts('pixelsPerLabel');
+ var pixels_per_tick = /** @type{number} */(opts('pixelsPerLabel'));
for (var i = 0; i < Dygraph.NUM_GRANULARITIES; i++) {
var num_ticks = Dygraph.numDateTicks(a, b, i);
if (pixels / num_ticks >= pixels_per_tick) {
return -1;
};
+/**
+ * @param {number} start_time
+ * @param {number} end_time
+ * @param {number} granularity (one of the granularities enumerated above)
+ * @return {number} Number of ticks that would result.
+ */
Dygraph.numDateTicks = function(start_time, end_time, granularity) {
if (granularity < Dygraph.MONTHLY) {
// Generate one tick mark for every fixed interval of time.
}
};
+/**
+ * @param {number} start_time
+ * @param {number} end_time
+ * @param {number} granularity (one of the granularities enumerated above)
+ * @param {function(string):*} opts Function mapping from option name -> value.
+ * @param {Dygraph=} dg
+ * @return {!Dygraph.TickList}
+ */
Dygraph.getDateAxis = function(start_time, end_time, granularity, opts, dg) {
- var formatter = opts("axisLabelFormatter");
+ var formatter = /** @type{AxisLabelFormatter} */(
+ opts("axisLabelFormatter"));
var ticks = [];
var t;
// for this granularity.
var g = spacing / 1000;
var d = new Date(start_time);
- d.setMilliseconds(0);
+ Dygraph.setDateSameTZ(d, {ms: 0});
+
var x;
if (g <= 60) { // seconds
- x = d.getSeconds(); d.setSeconds(x - x % g);
+ x = d.getSeconds();
+ Dygraph.setDateSameTZ(d, {s: x - x % g});
} else {
- d.setSeconds(0);
+ Dygraph.setDateSameTZ(d, {s: 0});
g /= 60;
if (g <= 60) { // minutes
- x = d.getMinutes(); d.setMinutes(x - x % g);
+ x = d.getMinutes();
+ Dygraph.setDateSameTZ(d, {m: x - x % g});
} else {
- d.setMinutes(0);
+ Dygraph.setDateSameTZ(d, {m: 0});
g /= 60;
if (g <= 24) { // days
- x = d.getHours(); d.setHours(x - x % g);
+ x = d.getHours();
+ d.setHours(x - x % g);
} else {
d.setHours(0);
g /= 24;
}
start_time = d.getTime();
+ // For spacings coarser than two-hourly, we want to ignore daylight
+ // savings transitions to get consistent ticks. For finer-grained ticks,
+ // it's essential to show the DST transition in all its messiness.
+ var start_offset_min = new Date(start_time).getTimezoneOffset();
+ var check_dst = (spacing >= Dygraph.SHORT_SPACINGS[Dygraph.TWO_HOURLY]);
+
for (t = start_time; t <= end_time; t += spacing) {
+ var d = new Date(t);
+
+ // This ensures that we stay on the same hourly "rhythm" across
+ // daylight savings transitions. Without this, the ticks could get off
+ // by an hour. See tests/daylight-savings.html or issue 147.
+ if (check_dst && d.getTimezoneOffset() != start_offset_min) {
+ var delta_min = d.getTimezoneOffset() - start_offset_min;
+ t += delta_min * 60 * 1000;
+ d = new Date(t);
+ start_offset_min = d.getTimezoneOffset();
+
+ // Check whether we've backed into the previous timezone again.
+ // This can happen during a "spring forward" transition. In this case,
+ // it's best to skip this tick altogether (we may be shooting for a
+ // non-existent time like the 2AM that's skipped) and go to the next
+ // one.
+ if (new Date(t + spacing).getTimezoneOffset() != start_offset_min) {
+ t += spacing;
+ d = new Date(t);
+ start_offset_min = d.getTimezoneOffset();
+ }
+ }
+
ticks.push({ v:t,
- label: formatter(new Date(t), granularity, opts, dg)
+ label: formatter(d, granularity, opts, dg)
});
}
} else {
return ticks;
};
-// These are set here so that this file can be included after dygraph.js.
-Dygraph.DEFAULT_ATTRS.axes.x.ticker = Dygraph.dateTicker;
-Dygraph.DEFAULT_ATTRS.axes.y.ticker = Dygraph.numericTicks;
-Dygraph.DEFAULT_ATTRS.axes.y2.ticker = Dygraph.numericTicks;
+// These are set here so that this file can be included after dygraph.js
+// or independently.
+if (Dygraph &&
+ Dygraph.DEFAULT_ATTRS &&
+ Dygraph.DEFAULT_ATTRS['axes'] &&
+ Dygraph.DEFAULT_ATTRS['axes']['x'] &&
+ Dygraph.DEFAULT_ATTRS['axes']['y'] &&
+ Dygraph.DEFAULT_ATTRS['axes']['y2']) {
+ Dygraph.DEFAULT_ATTRS['axes']['x']['ticker'] = Dygraph.dateTicker;
+ Dygraph.DEFAULT_ATTRS['axes']['y']['ticker'] = Dygraph.numericTicks;
+ Dygraph.DEFAULT_ATTRS['axes']['y2']['ticker'] = Dygraph.numericTicks;
+}