X-Git-Url: https://adrianiainlam.tk/git/?a=blobdiff_plain;f=dygraph-tickers.js;h=f4778b12b7a3ddc918bcafcc61800bbe914809c3;hb=d57dd6f2d72c2cf8aa342746076246effd10c8e3;hp=a17519ee66cbb76e3c9264fc20af561219702492;hpb=c0f54d4f7444bea88d6c26020c566b42b3fe45e5;p=dygraphs.git diff --git a/dygraph-tickers.js b/dygraph-tickers.js index a17519e..f4778b1 100644 --- a/dygraph-tickers.js +++ b/dygraph-tickers.js @@ -58,19 +58,46 @@ * middle of the years. */ +/*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.= + * ): 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 = opts('pixelsPerLabel'); + var pixels_per_tick = /** @type{number} */(opts('pixelsPerLabel')); var ticks = []; + var i, j, tickV, nTicks; if (vals) { - for (var i = 0; i < vals.length; i++) { + 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")) { - var nTicks = Math.floor(pixels / pixels_per_tick); + 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) { @@ -87,7 +114,7 @@ Dygraph.numericTicks = function(a, b, pixels, opts, dygraph, vals) { 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) { + if (lastDisplayed === null) { lastDisplayed = { tickValue : tickValue, pixel_coord : pixel_coord @@ -110,98 +137,76 @@ Dygraph.numericTicks = function(a, b, pixels, opts, dygraph, vals) { } // ticks.length won't be 0 if the log scale function finds values to insert. - if (ticks.length == 0) { + 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) { - var mults = [1, 2, 4, 8]; + mults = [1, 2, 4, 8, 16, 32, 64, 128, 256]; + base = 16; } else { - var mults = [1, 2, 5]; + mults = [1, 2, 5, 10, 20, 50, 100]; + base = 10; } - var scale, low_val, high_val, nTicks; - for (var i = -10; i < 50; i++) { - if (kmg2) { - 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(a / scale) * scale; - high_val = Math.ceil(b / scale) * scale; - nTicks = Math.abs(high_val - low_val) / scale; - var 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; } // 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; + for (i = 0; i < nTicks; i++) { + tickV = low_val + i * scale; ticks.push( {v: tickV} ); } } } - // Add formatted labels to the ticks. - var k; - var k_labels = []; - if (opts("labelsKMB")) { - k = 1000; - k_labels = [ "K", "M", "B", "T" ]; - } - if (opts("labelsKMG2")) { - if (k) self.warn("Setting both labelsKMB and labelsKMG2. Pick one!"); - k = 1024; - k_labels = [ "k", "M", "G", "T" ]; - } - - var formatter = opts('axisLabelFormatter'); + var formatter = /**@type{AxisLabelFormatter}*/(opts('axisLabelFormatter')); // Add labels to the ticks. - for (var i = 0; i < ticks.length; i++) { + for (i = 0; i < ticks.length; i++) { if (ticks[i].label !== undefined) continue; // Use current label. - var 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 = k*k*k*k; - for (var j = 3; 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 pixels_per_tick = opts('pixelsPerLabel'); - var chosen = -1; - for (var i = 0; i < Dygraph.NUM_GRANULARITIES; i++) { - var num_ticks = Dygraph.numDateTicks(a, b, i); - if (pixels / num_ticks >= pixels_per_tick) { - chosen = i; - break; - } - } + var chosen = Dygraph.pickDateTickGranularity(a, b, pixels, opts); if (chosen >= 0) { return Dygraph.getDateAxis(a, b, chosen, opts, dygraph); @@ -212,6 +217,7 @@ Dygraph.dateTicker = function(a, b, pixels, opts, dygraph, vals) { }; // Time granularity enumeration +// TODO(danvk): make this an @enum Dygraph.SECONDLY = 0; Dygraph.TWO_SECONDLY = 1; Dygraph.FIVE_SECONDLY = 2; @@ -235,6 +241,7 @@ Dygraph.DECADAL = 19; Dygraph.CENTENNIAL = 20; Dygraph.NUM_GRANULARITIES = 21; +/** @type {Array.} */ Dygraph.SHORT_SPACINGS = []; Dygraph.SHORT_SPACINGS[Dygraph.SECONDLY] = 1000 * 1; Dygraph.SHORT_SPACINGS[Dygraph.TWO_SECONDLY] = 1000 * 2; @@ -252,12 +259,45 @@ Dygraph.SHORT_SPACINGS[Dygraph.SIX_HOURLY] = 1000 * 3600 * 6; Dygraph.SHORT_SPACINGS[Dygraph.DAILY] = 1000 * 86400; Dygraph.SHORT_SPACINGS[Dygraph.WEEKLY] = 1000 * 604800; +/** + * A collection of objects specifying where it is acceptable to place tick + * marks for granularities larger than WEEKLY. + * 'months' is an array of month indexes on which to place tick marks. + * 'year_mod' ticks are placed when year % year_mod = 0. + * @type {Array.} + */ +Dygraph.LONG_TICK_PLACEMENTS = []; +Dygraph.LONG_TICK_PLACEMENTS[Dygraph.MONTHLY] = { + months : [0,1,2,3,4,5,6,7,8,9,10,11], + year_mod : 1 +}; +Dygraph.LONG_TICK_PLACEMENTS[Dygraph.QUARTERLY] = { + months: [0,3,6,9], + year_mod: 1 +}; +Dygraph.LONG_TICK_PLACEMENTS[Dygraph.BIANNUAL] = { + months: [0,6], + year_mod: 1 +}; +Dygraph.LONG_TICK_PLACEMENTS[Dygraph.ANNUAL] = { + months: [0], + year_mod: 1 +}; +Dygraph.LONG_TICK_PLACEMENTS[Dygraph.DECADAL] = { + months: [0], + year_mod: 10 +}; +Dygraph.LONG_TICK_PLACEMENTS[Dygraph.CENTENNIAL] = { + months: [0], + year_mod: 100 +}; + /** - * @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.} */ Dygraph.PREFERRED_LOG_TICK_VALUES = function() { var vals = []; @@ -271,51 +311,89 @@ Dygraph.PREFERRED_LOG_TICK_VALUES = function() { 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; +}; + +/** + * @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. var spacing = Dygraph.SHORT_SPACINGS[granularity]; return Math.floor(0.5 + 1.0 * (end_time - start_time) / spacing); } else { - var year_mod = 1; // e.g. to only print one point every 10 years. - var num_months = 12; - if (granularity == Dygraph.QUARTERLY) num_months = 3; - if (granularity == Dygraph.BIANNUAL) num_months = 2; - if (granularity == Dygraph.ANNUAL) num_months = 1; - if (granularity == Dygraph.DECADAL) { num_months = 1; year_mod = 10; } - if (granularity == Dygraph.CENTENNIAL) { num_months = 1; year_mod = 100; } + var tickPlacement = Dygraph.LONG_TICK_PLACEMENTS[granularity]; var msInYear = 365.2524 * 24 * 3600 * 1000; var num_years = 1.0 * (end_time - start_time) / msInYear; - return Math.floor(0.5 + 1.0 * num_years * num_months / year_mod); + return Math.floor(0.5 + 1.0 * num_years * tickPlacement.months.length / tickPlacement.year_mod); } }; +/** + * @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; + if (granularity < Dygraph.MONTHLY) { // Generate one tick mark for every fixed interval of time. var spacing = Dygraph.SHORT_SPACINGS[granularity]; - var format = '%d%b'; // e.g. "1Jan" // Find a time less than start_time which occurs on a "nice" time boundary // for this granularity. var g = spacing / 1000; var d = new Date(start_time); + Dygraph.setDateSameTZ(d, {ms: 0}); + + var x; if (g <= 60) { // seconds - var 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 - var 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 - var x = d.getHours(); d.setHours(x - x % g); + x = d.getHours(); + d.setHours(x - x % g); } else { d.setHours(0); g /= 24; @@ -328,9 +406,38 @@ Dygraph.getDateAxis = function(start_time, end_time, granularity, opts, dg) { } start_time = d.getTime(); - for (var t = start_time; t <= end_time; t += spacing) { + // 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) { + 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 { @@ -340,20 +447,9 @@ Dygraph.getDateAxis = function(start_time, end_time, granularity, opts, dg) { var months; var year_mod = 1; // e.g. to only print one point every 10 years. - if (granularity == Dygraph.MONTHLY) { - months = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 ]; - } else if (granularity == Dygraph.QUARTERLY) { - months = [ 0, 3, 6, 9 ]; - } else if (granularity == Dygraph.BIANNUAL) { - months = [ 0, 6 ]; - } else if (granularity == Dygraph.ANNUAL) { - months = [ 0 ]; - } else if (granularity == Dygraph.DECADAL) { - months = [ 0 ]; - year_mod = 10; - } else if (granularity == Dygraph.CENTENNIAL) { - months = [ 0 ]; - year_mod = 100; + if (granularity < Dygraph.NUM_GRANULARITIES) { + months = Dygraph.LONG_TICK_PLACEMENTS[granularity].months; + year_mod = Dygraph.LONG_TICK_PLACEMENTS[granularity].year_mod; } else { Dygraph.warn("Span of dates is too long"); } @@ -362,10 +458,10 @@ Dygraph.getDateAxis = function(start_time, end_time, granularity, opts, dg) { var end_year = new Date(end_time).getFullYear(); var zeropad = Dygraph.zeropad; for (var i = start_year; i <= end_year; i++) { - if (i % year_mod != 0) continue; + if (i % year_mod !== 0) continue; for (var j = 0; j < months.length; j++) { var date_str = i + "/" + zeropad(1 + months[j]) + "/01"; - var t = Dygraph.dateStrToMillis(date_str); + t = Dygraph.dateStrToMillis(date_str); if (t < start_time || t > end_time) continue; ticks.push({ v:t, label: formatter(new Date(t), granularity, opts, dg) @@ -377,7 +473,15 @@ Dygraph.getDateAxis = function(start_time, end_time, granularity, opts, dg) { 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; +}