X-Git-Url: https://adrianiainlam.tk/git/?a=blobdiff_plain;f=src%2Fdygraph-tickers.js;fp=src%2Fdygraph-tickers.js;h=0f6b1ab092eeb3c367075d7995452df927b98cb6;hb=3123ca57f71d145bb5bcc4a2f754d3dff3225346;hp=0000000000000000000000000000000000000000;hpb=26ee953643ccd2d32e38e6b60b20e6a01c1dc9ba;p=dygraphs.git diff --git a/src/dygraph-tickers.js b/src/dygraph-tickers.js new file mode 100644 index 0000000..0f6b1ab --- /dev/null +++ b/src/dygraph-tickers.js @@ -0,0 +1,456 @@ +/** + * @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.= + * ): 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.} + */ +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; +} + +})();