3 * Copyright 2011 Dan Vanderkam (danvdk@gmail.com)
4 * MIT-licensed (http://opensource.org/licenses/MIT)
8 * @fileoverview Description of this file.
9 * @author danvk@google.com (Dan Vanderkam)
11 * A ticker is a function with the following interface:
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] },
19 * The returned value is called a "tick list".
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
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.
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.
37 * dygraph is the Dygraph object for which an axis is being constructed.
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.
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).
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
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.
61 /*jshint globalstrict: true */
62 /*global Dygraph:false */
65 /** @typedef {Array.<{v:number, label:string, label_v:(string|undefined)}>} */
68 /** @typedef {function(
75 * ): Dygraph.TickList}
80 /** @type {Dygraph.Ticker} */
81 Dygraph
.numericLinearTicks
= function(a
, b
, pixels
, opts
, dygraph
, vals
) {
82 var nonLogscaleOpts
= function(opt
) {
83 if (opt
=== 'logscale') return false;
86 return Dygraph
.numericTicks(a
, b
, pixels
, nonLogscaleOpts
, dygraph
, vals
);
89 /** @type {Dygraph.Ticker} */
90 Dygraph
.numericTicks
= function(a
, b
, pixels
, opts
, dygraph
, vals
) {
91 // This masks some numeric issues in older versions of Firefox,
92 // where 1.0/Math
.pow(10,2) != Math
.pow(10,-2).
93 /** @type {function(number,number):number} */
94 var pow
= function(base
, exp
) {
96 return 1.0 / Math
.pow(base
, -exp
);
98 return Math
.pow(base
, exp
);
101 var pixels_per_tick
= /** @type{number} */(opts('pixelsPerLabel'));
103 var i
, j
, tickV
, nTicks
;
105 for (i
= 0; i
< vals
.length
; i
++) {
106 ticks
.push({v
: vals
[i
]});
109 // TODO(danvk): factor this log-scale block out into a separate function.
110 if (opts("logscale")) {
111 nTicks
= Math
.floor(pixels
/ pixels_per_tick
);
112 var minIdx
= Dygraph
.binarySearch(a
, Dygraph
.PREFERRED_LOG_TICK_VALUES
, 1);
113 var maxIdx
= Dygraph
.binarySearch(b
, Dygraph
.PREFERRED_LOG_TICK_VALUES
, -1);
118 maxIdx
= Dygraph
.PREFERRED_LOG_TICK_VALUES
.length
- 1;
120 // Count the number of tick values would appear, if we can get at least
121 // nTicks / 4 accept them
.
122 var lastDisplayed
= null;
123 if (maxIdx
- minIdx
>= nTicks
/ 4) {
124 for (var idx
= maxIdx
; idx
>= minIdx
; idx
--) {
125 var tickValue
= Dygraph
.PREFERRED_LOG_TICK_VALUES
[idx
];
126 var pixel_coord
= Math
.log(tickValue
/ a) / Math
.log(b
/ a
) * pixels
;
127 var tick
= { v
: tickValue
};
128 if (lastDisplayed
=== null) {
130 tickValue
: tickValue
,
131 pixel_coord
: pixel_coord
134 if (Math
.abs(pixel_coord
- lastDisplayed
.pixel_coord
) >= pixels_per_tick
) {
136 tickValue
: tickValue
,
137 pixel_coord
: pixel_coord
145 // Since we went in backwards order.
150 // ticks.length won't be 0 if the log scale function finds values to insert.
151 if (ticks
.length
=== 0) {
153 // Try labels every 1, 2, 5, 10, 20, 50, 100, etc.
154 // Calculate the resulting tick spacing (i.e. this.height_ / nTicks
).
155 // The first spacing greater than pixelsPerYLabel is what we use.
156 // TODO(danvk): version that works on a log scale.
157 var kmg2
= opts("labelsKMG2");
160 mults
= [1, 2, 4, 8, 16];
163 mults
= [1, 2, 5, 10];
167 var wanted_ticks
= pixels
/ pixels_per_tick
;
168 var units_per_tick
= Math
.abs(b
- a
) / wanted_ticks
;
169 var base_power
= Math
.floor(Math
.log(units_per_tick
) / Math
.log(base
));
170 var base_scale
= Math
.pow(base
, base_power
);
171 var scale
, low_val
, high_val
, nTicks
, spacing
;
172 for (j
= 0; j
< mults
.length
; j
++) {
173 scale
= base_scale
* mults
[j
];
174 low_val
= Math
.floor(a
/ scale
) * scale
;
175 high_val
= Math
.ceil(b
/ scale
) * scale
;
176 nTicks
= Math
.abs(high_val
- low_val
) / scale
;
177 spacing
= pixels
/ nTicks
;
178 if (spacing
> pixels_per_tick
) break;
181 // Construct the set of ticks.
182 // Allow reverse y-axis if it's explicitly requested.
183 if (low_val
> high_val
) scale
*= -1;
184 for (i
= 0; i
< nTicks
; i
++) {
185 tickV
= low_val
+ i
* scale
;
186 ticks
.push( {v
: tickV
} );
191 // Add formatted labels to the ticks.
195 if (opts("labelsKMB")) {
197 k_labels
= [ "K", "M", "B", "T", "Q" ];
199 if (opts("labelsKMG2")) {
200 if (k
) Dygraph
.warn("Setting both labelsKMB and labelsKMG2. Pick one!");
202 k_labels
= [ "k", "M", "G", "T", "P", "E", "Z", "Y" ];
203 m_labels
= [ "m", "u", "n", "p", "f", "a", "z", "y" ];
206 k
= k
|| 1; // If neither option is specified.
208 var formatter
= /**@type{AxisLabelFormatter}*/(opts('axisLabelFormatter'));
210 // Add labels to the ticks.
211 var digitsAfterDecimal
= /** @type{number} */(opts('digitsAfterDecimal'));
212 for (i
= 0; i
< ticks
.length
; i
++) {
213 if (ticks
[i
].label
!== undefined
) continue; // Use current label.
215 var absTickV
= Math
.abs(tickV
);
216 // TODO(danvk): set granularity to something appropriate here.
217 var label
= formatter(tickV
, 0, opts
, dygraph
);
218 if (k_labels
.length
> 0) {
219 // TODO(danvk): should this be integrated into the axisLabelFormatter?
220 // Round up to an appropriate unit.
221 var n
= pow(k
, k_labels
.length
);
222 for (j
= k_labels
.length
- 1; j
>= 0; j
--, n
/= k
) {
224 label
= Dygraph
.round_(tickV
/ n
, digitsAfterDecimal
) + k_labels
[j
];
229 if(opts("labelsKMG2")){
230 tickV
= String(tickV
.toExponential());
231 if(tickV
.split('e-').length
=== 2 && tickV
.split('e-')[1] >= 3 && tickV
.split('e-')[1] <= 24){
232 if(tickV
.split('e-')[1] % 3 > 0) {
233 label
= Dygraph
.round_(tickV
.split('e-')[0] /
234 pow(10,(tickV
.split('e-')[1] % 3)),
237 label
= Number(tickV
.split('e-')[0]).toFixed(2);
239 label
+= m_labels
[Math
.floor(tickV
.split('e-')[1] / 3) - 1];
242 ticks
[i
].label
= label
;
249 /** @type {Dygraph.Ticker} */
250 Dygraph
.dateTicker
= function(a
, b
, pixels
, opts
, dygraph
, vals
) {
251 var chosen
= Dygraph
.pickDateTickGranularity(a
, b
, pixels
, opts
);
254 return Dygraph
.getDateAxis(a
, b
, chosen
, opts
, dygraph
);
256 // this can happen if self.width_ is zero.
261 // Time granularity enumeration
262 // TODO(danvk): make this an @enum
263 Dygraph
.SECONDLY
= 0;
264 Dygraph
.TWO_SECONDLY
= 1;
265 Dygraph
.FIVE_SECONDLY
= 2;
266 Dygraph
.TEN_SECONDLY
= 3;
267 Dygraph
.THIRTY_SECONDLY
= 4;
268 Dygraph
.MINUTELY
= 5;
269 Dygraph
.TWO_MINUTELY
= 6;
270 Dygraph
.FIVE_MINUTELY
= 7;
271 Dygraph
.TEN_MINUTELY
= 8;
272 Dygraph
.THIRTY_MINUTELY
= 9;
274 Dygraph
.TWO_HOURLY
= 11;
275 Dygraph
.SIX_HOURLY
= 12;
278 Dygraph
.MONTHLY
= 15;
279 Dygraph
.QUARTERLY
= 16;
280 Dygraph
.BIANNUAL
= 17;
282 Dygraph
.DECADAL
= 19;
283 Dygraph
.CENTENNIAL
= 20;
284 Dygraph
.NUM_GRANULARITIES
= 21;
286 /** @type {Array.<number>} */
287 Dygraph
.SHORT_SPACINGS
= [];
288 Dygraph
.SHORT_SPACINGS
[Dygraph
.SECONDLY
] = 1000 * 1;
289 Dygraph
.SHORT_SPACINGS
[Dygraph
.TWO_SECONDLY
] = 1000 * 2;
290 Dygraph
.SHORT_SPACINGS
[Dygraph
.FIVE_SECONDLY
] = 1000 * 5;
291 Dygraph
.SHORT_SPACINGS
[Dygraph
.TEN_SECONDLY
] = 1000 * 10;
292 Dygraph
.SHORT_SPACINGS
[Dygraph
.THIRTY_SECONDLY
] = 1000 * 30;
293 Dygraph
.SHORT_SPACINGS
[Dygraph
.MINUTELY
] = 1000 * 60;
294 Dygraph
.SHORT_SPACINGS
[Dygraph
.TWO_MINUTELY
] = 1000 * 60 * 2;
295 Dygraph
.SHORT_SPACINGS
[Dygraph
.FIVE_MINUTELY
] = 1000 * 60 * 5;
296 Dygraph
.SHORT_SPACINGS
[Dygraph
.TEN_MINUTELY
] = 1000 * 60 * 10;
297 Dygraph
.SHORT_SPACINGS
[Dygraph
.THIRTY_MINUTELY
] = 1000 * 60 * 30;
298 Dygraph
.SHORT_SPACINGS
[Dygraph
.HOURLY
] = 1000 * 3600;
299 Dygraph
.SHORT_SPACINGS
[Dygraph
.TWO_HOURLY
] = 1000 * 3600 * 2;
300 Dygraph
.SHORT_SPACINGS
[Dygraph
.SIX_HOURLY
] = 1000 * 3600 * 6;
301 Dygraph
.SHORT_SPACINGS
[Dygraph
.DAILY
] = 1000 * 86400;
302 Dygraph
.SHORT_SPACINGS
[Dygraph
.WEEKLY
] = 1000 * 604800;
305 * This is a list of human-friendly values at which to show tick marks on a log
306 * scale. It is k * 10^n, where k=1..9 and n=-39..+39, so:
307 * ..., 1, 2, 3, 4, 5, ..., 9, 10, 20, 30, ..., 90, 100, 200, 300, ...
308 * NOTE: this assumes that Dygraph.LOG_SCALE = 10.
309 * @type {Array.<number>}
311 Dygraph
.PREFERRED_LOG_TICK_VALUES
= function() {
313 for (var power
= -39; power
<= 39; power
++) {
314 var range
= Math
.pow(10, power
);
315 for (var mult
= 1; mult
<= 9; mult
++) {
316 var val
= range
* mult
;
324 * Determine the correct granularity of ticks on a date axis.
326 * @param {number} a Left edge of the chart (ms)
327 * @param {number} b Right edge of the chart (ms)
328 * @param {number} pixels Size of the chart in the relevant dimension (width).
329 * @param {function(string):*} opts Function mapping from option name ->
331 * @return {number} The appropriate axis granularity for this chart. See the
332 * enumeration of possible values in dygraph-tickers.js.
334 Dygraph
.pickDateTickGranularity
= function(a
, b
, pixels
, opts
) {
335 var pixels_per_tick
= /** @type{number} */(opts('pixelsPerLabel'));
336 for (var i
= 0; i
< Dygraph
.NUM_GRANULARITIES
; i
++) {
337 var num_ticks
= Dygraph
.numDateTicks(a
, b
, i
);
338 if (pixels
/ num_ticks
>= pixels_per_tick
) {
346 * @param {number} start_time
347 * @param {number} end_time
348 * @param {number} granularity (one of the granularities enumerated above)
349 * @return {number} Number of ticks that would result.
351 Dygraph
.numDateTicks
= function(start_time
, end_time
, granularity
) {
352 if (granularity
< Dygraph
.MONTHLY
) {
353 // Generate one tick mark for every fixed interval of time.
354 var spacing
= Dygraph
.SHORT_SPACINGS
[granularity
];
355 return Math
.floor(0.5 + 1.0 * (end_time
- start_time
) / spacing
);
357 var year_mod
= 1; // e.g. to only print one point every 10 years.
359 if (granularity
== Dygraph
.QUARTERLY
) num_months
= 3;
360 if (granularity
== Dygraph
.BIANNUAL
) num_months
= 2;
361 if (granularity
== Dygraph
.ANNUAL
) num_months
= 1;
362 if (granularity
== Dygraph
.DECADAL
) { num_months
= 1; year_mod
= 10; }
363 if (granularity
== Dygraph
.CENTENNIAL
) { num_months
= 1; year_mod
= 100; }
365 var msInYear
= 365.2524 * 24 * 3600 * 1000;
366 var num_years
= 1.0 * (end_time
- start_time
) / msInYear
;
367 return Math
.floor(0.5 + 1.0 * num_years
* num_months
/ year_mod
);
372 * @param {number} start_time
373 * @param {number} end_time
374 * @param {number} granularity (one of the granularities enumerated above)
375 * @param {function(string):*} opts Function mapping from option name -> value.
376 * @param {Dygraph=} dg
377 * @return {!Dygraph.TickList}
379 Dygraph
.getDateAxis
= function(start_time
, end_time
, granularity
, opts
, dg
) {
380 var formatter
= /** @type{AxisLabelFormatter} */(
381 opts("axisLabelFormatter"));
385 if (granularity
< Dygraph
.MONTHLY
) {
386 // Generate one tick mark for every fixed interval of time.
387 var spacing
= Dygraph
.SHORT_SPACINGS
[granularity
];
389 // Find a time less than start_time which occurs on a "nice" time boundary
390 // for this granularity.
391 var g
= spacing
/ 1000;
392 var d
= new Date(start_time
);
393 d
.setMilliseconds(0);
395 if (g
<= 60) { // seconds
396 x
= d
.getSeconds(); d
.setSeconds(x
- x
% g
);
400 if (g
<= 60) { // minutes
401 x
= d
.getMinutes(); d
.setMinutes(x
- x
% g
);
406 if (g
<= 24) { // days
407 x
= d
.getHours(); d
.setHours(x
- x
% g
);
412 if (g
== 7) { // one week
413 d
.setDate(d
.getDate() - d
.getDay());
418 start_time
= d
.getTime();
420 for (t
= start_time
; t
<= end_time
; t
+= spacing
) {
422 label
: formatter(new Date(t
), granularity
, opts
, dg
)
426 // Display a tick mark on the first of a set of months of each year.
427 // Years get a tick mark iff y % year_mod == 0. This is useful for
428 // displaying a tick mark once every 10 years, say, on long time scales.
430 var year_mod
= 1; // e.g. to only print one point every 10 years.
432 if (granularity
== Dygraph
.MONTHLY
) {
433 months
= [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 ];
434 } else if (granularity
== Dygraph
.QUARTERLY
) {
435 months
= [ 0, 3, 6, 9 ];
436 } else if (granularity
== Dygraph
.BIANNUAL
) {
438 } else if (granularity
== Dygraph
.ANNUAL
) {
440 } else if (granularity
== Dygraph
.DECADAL
) {
443 } else if (granularity
== Dygraph
.CENTENNIAL
) {
447 Dygraph
.warn("Span of dates is too long");
450 var start_year
= new Date(start_time
).getFullYear();
451 var end_year
= new Date(end_time
).getFullYear();
452 var zeropad
= Dygraph
.zeropad
;
453 for (var i
= start_year
; i
<= end_year
; i
++) {
454 if (i
% year_mod
!== 0) continue;
455 for (var j
= 0; j
< months
.length
; j
++) {
456 var date_str
= i
+ "/" + zeropad(1 + months[j]) + "/01";
457 t
= Dygraph
.dateStrToMillis(date_str
);
458 if (t
< start_time
|| t
> end_time
) continue;
460 label
: formatter(new Date(t
), granularity
, opts
, dg
)
469 // These are set here so that this file can be included after dygraph.js.
470 Dygraph
.DEFAULT_ATTRS
['axes']['x']['ticker'] = Dygraph
.dateTicker
;
471 Dygraph
.DEFAULT_ATTRS
['axes']['y']['ticker'] = Dygraph
.numericTicks
;
472 Dygraph
.DEFAULT_ATTRS
['axes']['y2']['ticker'] = Dygraph
.numericTicks
;