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1/**
2 * @license
3 * Copyright 2011 Dan Vanderkam (danvdk@gmail.com)
4 * MIT-licensed (http://opensource.org/licenses/MIT)
5 */
6
7/**
8 * @fileoverview Description of this file.
9 * @author danvk@google.com (Dan Vanderkam)
10 *
11 * A ticker is a function with the following interface:
12 *
13 * function(a, b, pixels, options_view, dygraph, forced_values);
14 * -> [ { v: tick1_v, label: tick1_label[, label_v: label_v1] },
15 * { v: tick2_v, label: tick2_label[, label_v: label_v2] },
16 * ...
17 * ]
18 *
19 * The returned value is called a "tick list".
20 *
21 * Arguments
22 * ---------
23 *
24 * [a, b] is the range of the axis for which ticks are being generated. For a
25 * numeric axis, these will simply be numbers. For a date axis, these will be
26 * millis since epoch (convertable to Date objects using "new Date(a)" and "new
27 * Date(b)").
28 *
29 * opts provides access to chart- and axis-specific options. It can be used to
30 * access number/date formatting code/options, check for a log scale, etc.
31 *
32 * pixels is the length of the axis in pixels. opts('pixelsPerLabel') is the
33 * minimum amount of space to be allotted to each label. For instance, if
34 * pixels=400 and opts('pixelsPerLabel')=40 then the ticker should return
35 * between zero and ten (400/40) ticks.
36 *
37 * dygraph is the Dygraph object for which an axis is being constructed.
38 *
39 * forced_values is used for secondary y-axes. The tick positions are typically
40 * set by the primary y-axis, so the secondary y-axis has no choice in where to
41 * put these. It simply has to generate labels for these data values.
42 *
43 * Tick lists
44 * ----------
45 * Typically a tick will have both a grid/tick line and a label at one end of
46 * that line (at the bottom for an x-axis, at left or right for the y-axis).
47 *
48 * A tick may be missing one of these two components:
49 * - If "label_v" is specified instead of "v", then there will be no tick or
50 * gridline, just a label.
51 * - Similarly, if "label" is not specified, then there will be a gridline
52 * without a label.
53 *
54 * This flexibility is useful in a few situations:
55 * - For log scales, some of the tick lines may be too close to all have labels.
56 * - For date scales where years are being displayed, it is desirable to display
57 * tick marks at the beginnings of years but labels (e.g. "2006") in the
58 * middle of the years.
59 */
60
61/*jshint globalstrict: true */
62/*global Dygraph:false */
63"use strict";
64
65Dygraph.numericLinearTicks = function(a, b, pixels, opts, dygraph, vals) {
66 var nonLogscaleOpts = function(opt) {
67 if (opt === 'logscale') return false;
68 return opts(opt);
69 };
70 return Dygraph.numericTicks(a, b, pixels, nonLogscaleOpts, dygraph, vals);
71};
72
73Dygraph.numericTicks = function(a, b, pixels, opts, dygraph, vals) {
74 var pixels_per_tick = opts('pixelsPerLabel');
75 var ticks = [];
76 var i, j, tickV, nTicks;
77 if (vals) {
78 for (i = 0; i < vals.length; i++) {
79 ticks.push({v: vals[i]});
80 }
81 } else {
82 // TODO(danvk): factor this log-scale block out into a separate function.
83 if (opts("logscale")) {
84 nTicks = Math.floor(pixels / pixels_per_tick);
85 var minIdx = Dygraph.binarySearch(a, Dygraph.PREFERRED_LOG_TICK_VALUES, 1);
86 var maxIdx = Dygraph.binarySearch(b, Dygraph.PREFERRED_LOG_TICK_VALUES, -1);
87 if (minIdx == -1) {
88 minIdx = 0;
89 }
90 if (maxIdx == -1) {
91 maxIdx = Dygraph.PREFERRED_LOG_TICK_VALUES.length - 1;
92 }
93 // Count the number of tick values would appear, if we can get at least
94 // nTicks / 4 accept them.
95 var lastDisplayed = null;
96 if (maxIdx - minIdx >= nTicks / 4) {
97 for (var idx = maxIdx; idx >= minIdx; idx--) {
98 var tickValue = Dygraph.PREFERRED_LOG_TICK_VALUES[idx];
99 var pixel_coord = Math.log(tickValue / a) / Math.log(b / a) * pixels;
100 var tick = { v: tickValue };
101 if (lastDisplayed === null) {
102 lastDisplayed = {
103 tickValue : tickValue,
104 pixel_coord : pixel_coord
105 };
106 } else {
107 if (Math.abs(pixel_coord - lastDisplayed.pixel_coord) >= pixels_per_tick) {
108 lastDisplayed = {
109 tickValue : tickValue,
110 pixel_coord : pixel_coord
111 };
112 } else {
113 tick.label = "";
114 }
115 }
116 ticks.push(tick);
117 }
118 // Since we went in backwards order.
119 ticks.reverse();
120 }
121 }
122
123 // ticks.length won't be 0 if the log scale function finds values to insert.
124 if (ticks.length === 0) {
125 // Basic idea:
126 // Try labels every 1, 2, 5, 10, 20, 50, 100, etc.
127 // Calculate the resulting tick spacing (i.e. this.height_ / nTicks).
128 // The first spacing greater than pixelsPerYLabel is what we use.
129 // TODO(danvk): version that works on a log scale.
130 var kmg2 = opts("labelsKMG2");
131 var mults;
132 if (kmg2) {
133 mults = [1, 2, 4, 8];
134 } else {
135 mults = [1, 2, 5];
136 }
137 var scale, low_val, high_val;
138 for (i = -10; i < 50; i++) {
139 var base_scale;
140 if (kmg2) {
141 base_scale = Math.pow(16, i);
142 } else {
143 base_scale = Math.pow(10, i);
144 }
145 var spacing = 0;
146 for (j = 0; j < mults.length; j++) {
147 scale = base_scale * mults[j];
148 low_val = Math.floor(a / scale) * scale;
149 high_val = Math.ceil(b / scale) * scale;
150 nTicks = Math.abs(high_val - low_val) / scale;
151 spacing = pixels / nTicks;
152 // wish I could break out of both loops at once...
153 if (spacing > pixels_per_tick) break;
154 }
155 if (spacing > pixels_per_tick) break;
156 }
157
158 // Construct the set of ticks.
159 // Allow reverse y-axis if it's explicitly requested.
160 if (low_val > high_val) scale *= -1;
161 for (i = 0; i < nTicks; i++) {
162 tickV = low_val + i * scale;
163 ticks.push( {v: tickV} );
164 }
165 }
166 }
167
168 // Add formatted labels to the ticks.
169 var k;
170 var k_labels = [];
171 var m_labels = [];
172 if (opts("labelsKMB")) {
173 k = 1000;
174 k_labels = [ "K", "M", "B", "T", "Q" ];
175 }
176 if (opts("labelsKMG2")) {
177 if (k) Dygraph.warn("Setting both labelsKMB and labelsKMG2. Pick one!");
178 k = 1024;
179 k_labels = [ "k", "M", "G", "T", "P", "E", "Z", "Y" ];
180 m_labels = [ "m", "u", "n", "p", "f", "a", "z", "y" ];
181 }
182
183 var formatter = opts('axisLabelFormatter');
184
185 // Add labels to the ticks.
186 for (i = 0; i < ticks.length; i++) {
187 if (ticks[i].label !== undefined) continue; // Use current label.
188 tickV = ticks[i].v;
189 var absTickV = Math.abs(tickV);
190 // TODO(danvk): set granularity to something appropriate here.
191 var label = formatter(tickV, 0, opts, dygraph);
192 if (k_labels.length > 0) {
193 // TODO(danvk): should this be integrated into the axisLabelFormatter?
194 // Round up to an appropriate unit.
195 var n = Math.pow(k, k_labels.length);
196 for (j = k_labels.length - 1; j >= 0; j--, n /= k) {
197 if (absTickV >= n) {
198 label = Dygraph.round_(tickV / n, opts('digitsAfterDecimal')) +
199 k_labels[j];
200 break;
201 }
202 }
203 }
204 if(opts("labelsKMG2")){
205 tickV = String(tickV.toExponential());
206 if(tickV.split('e-').length === 2 && tickV.split('e-')[1] >= 3 && tickV.split('e-')[1] <= 24){
207 if(tickV.split('e-')[1] % 3 > 0) {
208 label = Dygraph.round_(tickV.split('e-')[0] /
209 Math.pow(10,(tickV.split('e-')[1] % 3)),
210 opts('digitsAfterDecimal'));
211 } else {
212 label = Number(tickV.split('e-')[0]).toFixed(2);
213 }
214 label += m_labels[Math.floor(tickV.split('e-')[1] / 3) - 1];
215 }
216 }
217 ticks[i].label = label;
218 }
219
220 return ticks;
221};
222
223
224Dygraph.dateTicker = function(a, b, pixels, opts, dygraph, vals) {
225 var chosen = Dygraph.pickDateTickGranularity(a, b, pixels, opts);
226
227 if (chosen >= 0) {
228 return Dygraph.getDateAxis(a, b, chosen, opts, dygraph);
229 } else {
230 // this can happen if self.width_ is zero.
231 return [];
232 }
233};
234
235// Time granularity enumeration
236Dygraph.SECONDLY = 0;
237Dygraph.TWO_SECONDLY = 1;
238Dygraph.FIVE_SECONDLY = 2;
239Dygraph.TEN_SECONDLY = 3;
240Dygraph.THIRTY_SECONDLY = 4;
241Dygraph.MINUTELY = 5;
242Dygraph.TWO_MINUTELY = 6;
243Dygraph.FIVE_MINUTELY = 7;
244Dygraph.TEN_MINUTELY = 8;
245Dygraph.THIRTY_MINUTELY = 9;
246Dygraph.HOURLY = 10;
247Dygraph.TWO_HOURLY = 11;
248Dygraph.SIX_HOURLY = 12;
249Dygraph.DAILY = 13;
250Dygraph.WEEKLY = 14;
251Dygraph.MONTHLY = 15;
252Dygraph.QUARTERLY = 16;
253Dygraph.BIANNUAL = 17;
254Dygraph.ANNUAL = 18;
255Dygraph.DECADAL = 19;
256Dygraph.CENTENNIAL = 20;
257Dygraph.NUM_GRANULARITIES = 21;
258
259Dygraph.SHORT_SPACINGS = [];
260Dygraph.SHORT_SPACINGS[Dygraph.SECONDLY] = 1000 * 1;
261Dygraph.SHORT_SPACINGS[Dygraph.TWO_SECONDLY] = 1000 * 2;
262Dygraph.SHORT_SPACINGS[Dygraph.FIVE_SECONDLY] = 1000 * 5;
263Dygraph.SHORT_SPACINGS[Dygraph.TEN_SECONDLY] = 1000 * 10;
264Dygraph.SHORT_SPACINGS[Dygraph.THIRTY_SECONDLY] = 1000 * 30;
265Dygraph.SHORT_SPACINGS[Dygraph.MINUTELY] = 1000 * 60;
266Dygraph.SHORT_SPACINGS[Dygraph.TWO_MINUTELY] = 1000 * 60 * 2;
267Dygraph.SHORT_SPACINGS[Dygraph.FIVE_MINUTELY] = 1000 * 60 * 5;
268Dygraph.SHORT_SPACINGS[Dygraph.TEN_MINUTELY] = 1000 * 60 * 10;
269Dygraph.SHORT_SPACINGS[Dygraph.THIRTY_MINUTELY] = 1000 * 60 * 30;
270Dygraph.SHORT_SPACINGS[Dygraph.HOURLY] = 1000 * 3600;
271Dygraph.SHORT_SPACINGS[Dygraph.TWO_HOURLY] = 1000 * 3600 * 2;
272Dygraph.SHORT_SPACINGS[Dygraph.SIX_HOURLY] = 1000 * 3600 * 6;
273Dygraph.SHORT_SPACINGS[Dygraph.DAILY] = 1000 * 86400;
274Dygraph.SHORT_SPACINGS[Dygraph.WEEKLY] = 1000 * 604800;
275
276/**
277 * @private
278 * This is a list of human-friendly values at which to show tick marks on a log
279 * scale. It is k * 10^n, where k=1..9 and n=-39..+39, so:
280 * ..., 1, 2, 3, 4, 5, ..., 9, 10, 20, 30, ..., 90, 100, 200, 300, ...
281 * NOTE: this assumes that Dygraph.LOG_SCALE = 10.
282 */
283Dygraph.PREFERRED_LOG_TICK_VALUES = function() {
284 var vals = [];
285 for (var power = -39; power <= 39; power++) {
286 var range = Math.pow(10, power);
287 for (var mult = 1; mult <= 9; mult++) {
288 var val = range * mult;
289 vals.push(val);
290 }
291 }
292 return vals;
293}();
294
295/**
296 * Determine the correct granularity of ticks on a date axis.
297 *
298 * @param {Number} a Left edge of the chart (ms)
299 * @param {Number} b Right edge of the chart (ms)
300 * @param {Number} pixels Size of the chart in the relevant dimension (width).
301 * @param {Function} opts Function mapping from option name -> value.
302 * @return {Number} The appropriate axis granularity for this chart. See the
303 * enumeration of possible values in dygraph-tickers.js.
304 */
305Dygraph.pickDateTickGranularity = function(a, b, pixels, opts) {
306 var pixels_per_tick = opts('pixelsPerLabel');
307 for (var i = 0; i < Dygraph.NUM_GRANULARITIES; i++) {
308 var num_ticks = Dygraph.numDateTicks(a, b, i);
309 if (pixels / num_ticks >= pixels_per_tick) {
310 return i;
311 }
312 }
313 return -1;
314};
315
316Dygraph.numDateTicks = function(start_time, end_time, granularity) {
317 if (granularity < Dygraph.MONTHLY) {
318 // Generate one tick mark for every fixed interval of time.
319 var spacing = Dygraph.SHORT_SPACINGS[granularity];
320 return Math.floor(0.5 + 1.0 * (end_time - start_time) / spacing);
321 } else {
322 var year_mod = 1; // e.g. to only print one point every 10 years.
323 var num_months = 12;
324 if (granularity == Dygraph.QUARTERLY) num_months = 3;
325 if (granularity == Dygraph.BIANNUAL) num_months = 2;
326 if (granularity == Dygraph.ANNUAL) num_months = 1;
327 if (granularity == Dygraph.DECADAL) { num_months = 1; year_mod = 10; }
328 if (granularity == Dygraph.CENTENNIAL) { num_months = 1; year_mod = 100; }
329
330 var msInYear = 365.2524 * 24 * 3600 * 1000;
331 var num_years = 1.0 * (end_time - start_time) / msInYear;
332 return Math.floor(0.5 + 1.0 * num_years * num_months / year_mod);
333 }
334};
335
336Dygraph.getDateAxis = function(start_time, end_time, granularity, opts, dg) {
337 var formatter = opts("axisLabelFormatter");
338 var ticks = [];
339 var t;
340
341 if (granularity < Dygraph.MONTHLY) {
342 // Generate one tick mark for every fixed interval of time.
343 var spacing = Dygraph.SHORT_SPACINGS[granularity];
344
345 // Find a time less than start_time which occurs on a "nice" time boundary
346 // for this granularity.
347 var g = spacing / 1000;
348 var d = new Date(start_time);
349 d.setMilliseconds(0);
350 var x;
351 if (g <= 60) { // seconds
352 x = d.getSeconds(); d.setSeconds(x - x % g);
353 } else {
354 d.setSeconds(0);
355 g /= 60;
356 if (g <= 60) { // minutes
357 x = d.getMinutes(); d.setMinutes(x - x % g);
358 } else {
359 d.setMinutes(0);
360 g /= 60;
361
362 if (g <= 24) { // days
363 x = d.getHours(); d.setHours(x - x % g);
364 } else {
365 d.setHours(0);
366 g /= 24;
367
368 if (g == 7) { // one week
369 d.setDate(d.getDate() - d.getDay());
370 }
371 }
372 }
373 }
374 start_time = d.getTime();
375
376 for (t = start_time; t <= end_time; t += spacing) {
377 ticks.push({ v:t,
378 label: formatter(new Date(t), granularity, opts, dg)
379 });
380 }
381 } else {
382 // Display a tick mark on the first of a set of months of each year.
383 // Years get a tick mark iff y % year_mod == 0. This is useful for
384 // displaying a tick mark once every 10 years, say, on long time scales.
385 var months;
386 var year_mod = 1; // e.g. to only print one point every 10 years.
387
388 if (granularity == Dygraph.MONTHLY) {
389 months = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 ];
390 } else if (granularity == Dygraph.QUARTERLY) {
391 months = [ 0, 3, 6, 9 ];
392 } else if (granularity == Dygraph.BIANNUAL) {
393 months = [ 0, 6 ];
394 } else if (granularity == Dygraph.ANNUAL) {
395 months = [ 0 ];
396 } else if (granularity == Dygraph.DECADAL) {
397 months = [ 0 ];
398 year_mod = 10;
399 } else if (granularity == Dygraph.CENTENNIAL) {
400 months = [ 0 ];
401 year_mod = 100;
402 } else {
403 Dygraph.warn("Span of dates is too long");
404 }
405
406 var start_year = new Date(start_time).getFullYear();
407 var end_year = new Date(end_time).getFullYear();
408 var zeropad = Dygraph.zeropad;
409 for (var i = start_year; i <= end_year; i++) {
410 if (i % year_mod !== 0) continue;
411 for (var j = 0; j < months.length; j++) {
412 var date_str = i + "/" + zeropad(1 + months[j]) + "/01";
413 t = Dygraph.dateStrToMillis(date_str);
414 if (t < start_time || t > end_time) continue;
415 ticks.push({ v:t,
416 label: formatter(new Date(t), granularity, opts, dg)
417 });
418 }
419 }
420 }
421
422 return ticks;
423};
424
425// These are set here so that this file can be included after dygraph.js.
426Dygraph.DEFAULT_ATTRS.axes.x.ticker = Dygraph.dateTicker;
427Dygraph.DEFAULT_ATTRS.axes.y.ticker = Dygraph.numericTicks;
428Dygraph.DEFAULT_ATTRS.axes.y2.ticker = Dygraph.numericTicks;