X-Git-Url: https://adrianiainlam.tk/git/?a=blobdiff_plain;f=dygraph-tickers.js;h=155afb05241d4ab2ff7dae3f698968f4543324a3;hb=14ea2141f073e01b01708740414a17668a6aef3b;hp=64cf59f3e267cbf550b73b34d9f1a5f6600b3637;hpb=7a1f1877f3979293d8f2c64c2b274b09b93d4135;p=dygraphs.git diff --git a/dygraph-tickers.js b/dygraph-tickers.js index 64cf59f..155afb0 100644 --- a/dygraph-tickers.js +++ b/dygraph-tickers.js @@ -58,12 +58,36 @@ * 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.= + * ): 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) { @@ -120,30 +144,40 @@ Dygraph.numericTicks = function(a, b, pixels, opts, dygraph, 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; } @@ -157,47 +191,20 @@ Dygraph.numericTicks = function(a, b, pixels, opts, dygraph, vals) { } } - // 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) Dygraph.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 (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 = k*k*k*k; - for (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 chosen = Dygraph.pickDateTickGranularity(a, b, pixels, opts); @@ -210,6 +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; @@ -233,6 +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; @@ -251,11 +260,11 @@ Dygraph.SHORT_SPACINGS[Dygraph.DAILY] = 1000 * 86400; 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.} */ Dygraph.PREFERRED_LOG_TICK_VALUES = function() { var vals = []; @@ -272,15 +281,16 @@ Dygraph.PREFERRED_LOG_TICK_VALUES = function() { /** * 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) { @@ -290,6 +300,12 @@ Dygraph.pickDateTickGranularity = function(a, b, pixels, opts) { 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. @@ -310,8 +326,17 @@ Dygraph.numDateTicks = function(start_time, end_time, 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 = opts("axisLabelFormatter"); + var formatter = /** @type{AxisLabelFormatter} */( + opts("axisLabelFormatter")); var ticks = []; var t; @@ -323,20 +348,25 @@ Dygraph.getDateAxis = function(start_time, end_time, granularity, opts, dg) { // for this granularity. var g = spacing / 1000; var d = new Date(start_time); + 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; @@ -349,9 +379,38 @@ Dygraph.getDateAxis = function(start_time, end_time, granularity, opts, dg) { } 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) { + 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 { @@ -398,7 +457,15 @@ 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; +}