--- /dev/null
+/**
+ * @license
+ * Copyright 2011 Dan Vanderkam (danvdk@gmail.com)
+ * MIT-licensed (http://opensource.org/licenses/MIT)
+ */
+
+/**
+ * @fileoverview Description of this file.
+ * @author danvk@google.com (Dan Vanderkam)
+ *
+ * A ticker is a function with the following interface:
+ *
+ * function(a, b, pixels, options_view, dygraph, forced_values);
+ * -> [ { v: tick1_v, label: tick1_label[, label_v: label_v1] },
+ * { v: tick2_v, label: tick2_label[, label_v: label_v2] },
+ * ...
+ * ]
+ *
+ * The returned value is called a "tick list".
+ *
+ * Arguments
+ * ---------
+ *
+ * [a, b] is the range of the axis for which ticks are being generated. For a
+ * numeric axis, these will simply be numbers. For a date axis, these will be
+ * millis since epoch (convertable to Date objects using "new Date(a)" and "new
+ * Date(b)").
+ *
+ * opts provides access to chart- and axis-specific options. It can be used to
+ * access number/date formatting code/options, check for a log scale, etc.
+ *
+ * pixels is the length of the axis in pixels. opts('pixelsPerLabel') is the
+ * minimum amount of space to be allotted to each label. For instance, if
+ * pixels=400 and opts('pixelsPerLabel')=40 then the ticker should return
+ * between zero and ten (400/40) ticks.
+ *
+ * dygraph is the Dygraph object for which an axis is being constructed.
+ *
+ * forced_values is used for secondary y-axes. The tick positions are typically
+ * set by the primary y-axis, so the secondary y-axis has no choice in where to
+ * put these. It simply has to generate labels for these data values.
+ *
+ * Tick lists
+ * ----------
+ * Typically a tick will have both a grid/tick line and a label at one end of
+ * that line (at the bottom for an x-axis, at left or right for the y-axis).
+ *
+ * A tick may be missing one of these two components:
+ * - If "label_v" is specified instead of "v", then there will be no tick or
+ * gridline, just a label.
+ * - Similarly, if "label" is not specified, then there will be a gridline
+ * without a label.
+ *
+ * This flexibility is useful in a few situations:
+ * - For log scales, some of the tick lines may be too close to all have labels.
+ * - For date scales where years are being displayed, it is desirable to display
+ * tick marks at the beginnings of years but labels (e.g. "2006") in the
+ * middle of the years.
+ */
+
+/*jshint sub:true */
+/*global Dygraph:false */
+(function() {
+"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 opts(opt);
+ };
+ 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 = /** @type{number} */(opts('pixelsPerLabel'));
+ var ticks = [];
+ var i, j, tickV, nTicks;
+ if (vals) {
+ for (i = 0; i < vals.length; i++) {
+ ticks.push({v: vals[i]});
+ }
+ } else {
+ // TODO(danvk): factor this log-scale block out into a separate function.
+ if (opts("logscale")) {
+ nTicks = Math.floor(pixels / pixels_per_tick);
+ var minIdx = Dygraph.binarySearch(a, Dygraph.PREFERRED_LOG_TICK_VALUES, 1);
+ var maxIdx = Dygraph.binarySearch(b, Dygraph.PREFERRED_LOG_TICK_VALUES, -1);
+ if (minIdx == -1) {
+ minIdx = 0;
+ }
+ if (maxIdx == -1) {
+ maxIdx = Dygraph.PREFERRED_LOG_TICK_VALUES.length - 1;
+ }
+ // Count the number of tick values would appear, if we can get at least
+ // nTicks / 4 accept them.
+ var lastDisplayed = null;
+ if (maxIdx - minIdx >= nTicks / 4) {
+ for (var idx = maxIdx; idx >= minIdx; idx--) {
+ var tickValue = Dygraph.PREFERRED_LOG_TICK_VALUES[idx];
+ var pixel_coord = Math.log(tickValue / a) / Math.log(b / a) * pixels;
+ var tick = { v: tickValue };
+ if (lastDisplayed === null) {
+ lastDisplayed = {
+ tickValue : tickValue,
+ pixel_coord : pixel_coord
+ };
+ } else {
+ if (Math.abs(pixel_coord - lastDisplayed.pixel_coord) >= pixels_per_tick) {
+ lastDisplayed = {
+ tickValue : tickValue,
+ pixel_coord : pixel_coord
+ };
+ } else {
+ tick.label = "";
+ }
+ }
+ ticks.push(tick);
+ }
+ // Since we went in backwards order.
+ ticks.reverse();
+ }
+ }
+
+ // ticks.length won't be 0 if the log scale function finds values to insert.
+ if (ticks.length === 0) {
+ // 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.
+ var kmg2 = opts("labelsKMG2");
+ var mults, base;
+ if (kmg2) {
+ mults = [1, 2, 4, 8, 16, 32, 64, 128, 256];
+ base = 16;
+ } else {
+ mults = [1, 2, 5, 10, 20, 50, 100];
+ base = 10;
+ }
+
+ // 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;
+ }
+
+ // Construct the set of ticks.
+ // Allow reverse y-axis if it's explicitly requested.
+ if (low_val > high_val) scale *= -1;
+ for (i = 0; i <= nTicks; i++) {
+ tickV = low_val + i * scale;
+ ticks.push( {v: tickV} );
+ }
+ }
+ }
+
+ 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.
+ // TODO(danvk): set granularity to something appropriate here.
+ ticks[i].label = formatter.call(dygraph, 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);
+
+ if (chosen >= 0) {
+ return Dygraph.getDateAxis(a, b, chosen, opts, dygraph);
+ } else {
+ // this can happen if self.width_ is zero.
+ return [];
+ }
+};
+
+// Time granularity enumeration
+// TODO(danvk): make this an @enum
+Dygraph.SECONDLY = 0;
+Dygraph.TWO_SECONDLY = 1;
+Dygraph.FIVE_SECONDLY = 2;
+Dygraph.TEN_SECONDLY = 3;
+Dygraph.THIRTY_SECONDLY = 4;
+Dygraph.MINUTELY = 5;
+Dygraph.TWO_MINUTELY = 6;
+Dygraph.FIVE_MINUTELY = 7;
+Dygraph.TEN_MINUTELY = 8;
+Dygraph.THIRTY_MINUTELY = 9;
+Dygraph.HOURLY = 10;
+Dygraph.TWO_HOURLY = 11;
+Dygraph.SIX_HOURLY = 12;
+Dygraph.DAILY = 13;
+Dygraph.TWO_DAILY = 14;
+Dygraph.WEEKLY = 15;
+Dygraph.MONTHLY = 16;
+Dygraph.QUARTERLY = 17;
+Dygraph.BIANNUAL = 18;
+Dygraph.ANNUAL = 19;
+Dygraph.DECADAL = 20;
+Dygraph.CENTENNIAL = 21;
+Dygraph.NUM_GRANULARITIES = 22;
+
+// Date components enumeration (in the order of the arguments in Date)
+// TODO: make this an @enum
+Dygraph.DATEFIELD_Y = 0;
+Dygraph.DATEFIELD_M = 1;
+Dygraph.DATEFIELD_D = 2;
+Dygraph.DATEFIELD_HH = 3;
+Dygraph.DATEFIELD_MM = 4;
+Dygraph.DATEFIELD_SS = 5;
+Dygraph.DATEFIELD_MS = 6;
+Dygraph.NUM_DATEFIELDS = 7;
+
+
+/**
+ * The value of datefield will start at an even multiple of "step", i.e.
+ * if datefield=SS and step=5 then the first tick will be on a multiple of 5s.
+ *
+ * For granularities <= HOURLY, ticks are generated every `spacing` ms.
+ *
+ * At coarser granularities, ticks are generated by incrementing `datefield` by
+ * `step`. In this case, the `spacing` value is only used to estimate the
+ * number of ticks. It should roughly correspond to the spacing between
+ * adjacent ticks.
+ *
+ * @type {Array.<{datefield:number, step:number, spacing:number}>}
+ */
+Dygraph.TICK_PLACEMENT = [];
+Dygraph.TICK_PLACEMENT[Dygraph.SECONDLY] = {datefield: Dygraph.DATEFIELD_SS, step: 1, spacing: 1000 * 1};
+Dygraph.TICK_PLACEMENT[Dygraph.TWO_SECONDLY] = {datefield: Dygraph.DATEFIELD_SS, step: 2, spacing: 1000 * 2};
+Dygraph.TICK_PLACEMENT[Dygraph.FIVE_SECONDLY] = {datefield: Dygraph.DATEFIELD_SS, step: 5, spacing: 1000 * 5};
+Dygraph.TICK_PLACEMENT[Dygraph.TEN_SECONDLY] = {datefield: Dygraph.DATEFIELD_SS, step: 10, spacing: 1000 * 10};
+Dygraph.TICK_PLACEMENT[Dygraph.THIRTY_SECONDLY] = {datefield: Dygraph.DATEFIELD_SS, step: 30, spacing: 1000 * 30};
+Dygraph.TICK_PLACEMENT[Dygraph.MINUTELY] = {datefield: Dygraph.DATEFIELD_MM, step: 1, spacing: 1000 * 60};
+Dygraph.TICK_PLACEMENT[Dygraph.TWO_MINUTELY] = {datefield: Dygraph.DATEFIELD_MM, step: 2, spacing: 1000 * 60 * 2};
+Dygraph.TICK_PLACEMENT[Dygraph.FIVE_MINUTELY] = {datefield: Dygraph.DATEFIELD_MM, step: 5, spacing: 1000 * 60 * 5};
+Dygraph.TICK_PLACEMENT[Dygraph.TEN_MINUTELY] = {datefield: Dygraph.DATEFIELD_MM, step: 10, spacing: 1000 * 60 * 10};
+Dygraph.TICK_PLACEMENT[Dygraph.THIRTY_MINUTELY] = {datefield: Dygraph.DATEFIELD_MM, step: 30, spacing: 1000 * 60 * 30};
+Dygraph.TICK_PLACEMENT[Dygraph.HOURLY] = {datefield: Dygraph.DATEFIELD_HH, step: 1, spacing: 1000 * 3600};
+Dygraph.TICK_PLACEMENT[Dygraph.TWO_HOURLY] = {datefield: Dygraph.DATEFIELD_HH, step: 2, spacing: 1000 * 3600 * 2};
+Dygraph.TICK_PLACEMENT[Dygraph.SIX_HOURLY] = {datefield: Dygraph.DATEFIELD_HH, step: 6, spacing: 1000 * 3600 * 6};
+Dygraph.TICK_PLACEMENT[Dygraph.DAILY] = {datefield: Dygraph.DATEFIELD_D, step: 1, spacing: 1000 * 86400};
+Dygraph.TICK_PLACEMENT[Dygraph.TWO_DAILY] = {datefield: Dygraph.DATEFIELD_D, step: 2, spacing: 1000 * 86400 * 2};
+Dygraph.TICK_PLACEMENT[Dygraph.WEEKLY] = {datefield: Dygraph.DATEFIELD_D, step: 7, spacing: 1000 * 604800};
+Dygraph.TICK_PLACEMENT[Dygraph.MONTHLY] = {datefield: Dygraph.DATEFIELD_M, step: 1, spacing: 1000 * 7200 * 365.2524}; // 1e3 * 60 * 60 * 24 * 365.2524 / 12
+Dygraph.TICK_PLACEMENT[Dygraph.QUARTERLY] = {datefield: Dygraph.DATEFIELD_M, step: 3, spacing: 1000 * 21600 * 365.2524}; // 1e3 * 60 * 60 * 24 * 365.2524 / 4
+Dygraph.TICK_PLACEMENT[Dygraph.BIANNUAL] = {datefield: Dygraph.DATEFIELD_M, step: 6, spacing: 1000 * 43200 * 365.2524}; // 1e3 * 60 * 60 * 24 * 365.2524 / 2
+Dygraph.TICK_PLACEMENT[Dygraph.ANNUAL] = {datefield: Dygraph.DATEFIELD_Y, step: 1, spacing: 1000 * 86400 * 365.2524}; // 1e3 * 60 * 60 * 24 * 365.2524 * 1
+Dygraph.TICK_PLACEMENT[Dygraph.DECADAL] = {datefield: Dygraph.DATEFIELD_Y, step: 10, spacing: 1000 * 864000 * 365.2524}; // 1e3 * 60 * 60 * 24 * 365.2524 * 10
+Dygraph.TICK_PLACEMENT[Dygraph.CENTENNIAL] = {datefield: Dygraph.DATEFIELD_Y, step: 100, spacing: 1000 * 8640000 * 365.2524}; // 1e3 * 60 * 60 * 24 * 365.2524 * 100
+
+
+/**
+ * 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 = [];
+ for (var power = -39; power <= 39; power++) {
+ var range = Math.pow(10, power);
+ for (var mult = 1; mult <= 9; mult++) {
+ var val = range * mult;
+ vals.push(val);
+ }
+ }
+ return 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(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 = /** @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 i;
+ }
+ }
+ return -1;
+};
+
+/**
+ * Compute the number of ticks on a date axis for a given granularity.
+ * @param {number} start_time
+ * @param {number} end_time
+ * @param {number} granularity (one of the granularities enumerated above)
+ * @return {number} (Approximate) number of ticks that would result.
+ */
+Dygraph.numDateTicks = function(start_time, end_time, granularity) {
+ var spacing = Dygraph.TICK_PLACEMENT[granularity].spacing;
+ return Math.round(1.0 * (end_time - start_time) / spacing);
+};
+
+/**
+ * Compute the positions and labels of ticks on a date axis for a given granularity.
+ * @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 = /** @type{AxisLabelFormatter} */(
+ opts("axisLabelFormatter"));
+ var utc = opts("labelsUTC");
+ var accessors = utc ? Dygraph.DateAccessorsUTC : Dygraph.DateAccessorsLocal;
+
+ var datefield = Dygraph.TICK_PLACEMENT[granularity].datefield;
+ var step = Dygraph.TICK_PLACEMENT[granularity].step;
+ var spacing = Dygraph.TICK_PLACEMENT[granularity].spacing;
+
+ // Choose a nice tick position before the initial instant.
+ // Currently, this code deals properly with the existent daily granularities:
+ // DAILY (with step of 1) and WEEKLY (with step of 7 but specially handled).
+ // Other daily granularities (say TWO_DAILY) should also be handled specially
+ // by setting the start_date_offset to 0.
+ var start_date = new Date(start_time);
+ var date_array = [];
+ date_array[Dygraph.DATEFIELD_Y] = accessors.getFullYear(start_date);
+ date_array[Dygraph.DATEFIELD_M] = accessors.getMonth(start_date);
+ date_array[Dygraph.DATEFIELD_D] = accessors.getDate(start_date);
+ date_array[Dygraph.DATEFIELD_HH] = accessors.getHours(start_date);
+ date_array[Dygraph.DATEFIELD_MM] = accessors.getMinutes(start_date);
+ date_array[Dygraph.DATEFIELD_SS] = accessors.getSeconds(start_date);
+ date_array[Dygraph.DATEFIELD_MS] = accessors.getMilliseconds(start_date);
+
+ var start_date_offset = date_array[datefield] % step;
+ if (granularity == Dygraph.WEEKLY) {
+ // This will put the ticks on Sundays.
+ start_date_offset = accessors.getDay(start_date);
+ }
+
+ date_array[datefield] -= start_date_offset;
+ for (var df = datefield + 1; df < Dygraph.NUM_DATEFIELDS; df++) {
+ // The minimum value is 1 for the day of month, and 0 for all other fields.
+ date_array[df] = (df === Dygraph.DATEFIELD_D) ? 1 : 0;
+ }
+
+ // Generate the ticks.
+ // For granularities not coarser than HOURLY we use the fact that:
+ // the number of milliseconds between ticks is constant
+ // and equal to the defined spacing.
+ // Otherwise we rely on the 'roll over' property of the Date functions:
+ // when some date field is set to a value outside of its logical range,
+ // the excess 'rolls over' the next (more significant) field.
+ // However, when using local time with DST transitions,
+ // there are dates that do not represent any time value at all
+ // (those in the hour skipped at the 'spring forward'),
+ // and the JavaScript engines usually return an equivalent value.
+ // Hence we have to check that the date is properly increased at each step,
+ // returning a date at a nice tick position.
+ var ticks = [];
+ var tick_date = accessors.makeDate.apply(null, date_array);
+ var tick_time = tick_date.getTime();
+ if (granularity <= Dygraph.HOURLY) {
+ if (tick_time < start_time) {
+ tick_time += spacing;
+ tick_date = new Date(tick_time);
+ }
+ while (tick_time <= end_time) {
+ ticks.push({ v: tick_time,
+ label: formatter.call(dg, tick_date, granularity, opts, dg)
+ });
+ tick_time += spacing;
+ tick_date = new Date(tick_time);
+ }
+ } else {
+ if (tick_time < start_time) {
+ date_array[datefield] += step;
+ tick_date = accessors.makeDate.apply(null, date_array);
+ tick_time = tick_date.getTime();
+ }
+ while (tick_time <= end_time) {
+ if (granularity >= Dygraph.DAILY ||
+ accessors.getHours(tick_date) % step === 0) {
+ ticks.push({ v: tick_time,
+ label: formatter.call(dg, tick_date, granularity, opts, dg)
+ });
+ }
+ date_array[datefield] += step;
+ tick_date = accessors.makeDate.apply(null, date_array);
+ tick_time = tick_date.getTime();
+ }
+ }
+ return ticks;
+};
+
+// 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;
+}
+
+})();
projects / dygraphs.git / blobdiff