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 Dygraph
.numericLinearTicks
= function(a
, b
, pixels
, opts
, dygraph
, vals
) {
66 var nonLogscaleOpts
= function(opt
) {
67 if (opt
=== 'logscale') return false;
70 return Dygraph
.numericTicks(a
, b
, pixels
, nonLogscaleOpts
, dygraph
, vals
);
73 Dygraph
.numericTicks
= function(a
, b
, pixels
, opts
, dygraph
, vals
) {
74 // This masks some numeric issues in older versions of Firefox,
75 // where 1.0/Math
.pow(10,2) != Math
.pow(10,-2).
76 var pow
= function(base
, exp
) {
78 return 1.0 / Math
.pow(base
, -exp
);
80 return Math
.pow(base
, exp
);
83 var pixels_per_tick
= opts('pixelsPerLabel');
85 var i
, j
, tickV
, nTicks
;
87 for (i
= 0; i
< vals
.length
; i
++) {
88 ticks
.push({v
: vals
[i
]});
91 // TODO(danvk): factor this log-scale block out into a separate function.
92 if (opts("logscale")) {
93 nTicks
= Math
.floor(pixels
/ pixels_per_tick
);
94 var minIdx
= Dygraph
.binarySearch(a
, Dygraph
.PREFERRED_LOG_TICK_VALUES
, 1);
95 var maxIdx
= Dygraph
.binarySearch(b
, Dygraph
.PREFERRED_LOG_TICK_VALUES
, -1);
100 maxIdx
= Dygraph
.PREFERRED_LOG_TICK_VALUES
.length
- 1;
102 // Count the number of tick values would appear, if we can get at least
103 // nTicks / 4 accept them
.
104 var lastDisplayed
= null;
105 if (maxIdx
- minIdx
>= nTicks
/ 4) {
106 for (var idx
= maxIdx
; idx
>= minIdx
; idx
--) {
107 var tickValue
= Dygraph
.PREFERRED_LOG_TICK_VALUES
[idx
];
108 var pixel_coord
= Math
.log(tickValue
/ a) / Math
.log(b
/ a
) * pixels
;
109 var tick
= { v
: tickValue
};
110 if (lastDisplayed
=== null) {
112 tickValue
: tickValue
,
113 pixel_coord
: pixel_coord
116 if (Math
.abs(pixel_coord
- lastDisplayed
.pixel_coord
) >= pixels_per_tick
) {
118 tickValue
: tickValue
,
119 pixel_coord
: pixel_coord
127 // Since we went in backwards order.
132 // ticks.length won't be 0 if the log scale function finds values to insert.
133 if (ticks
.length
=== 0) {
135 // Try labels every 1, 2, 5, 10, 20, 50, 100, etc.
136 // Calculate the resulting tick spacing (i.e. this.height_ / nTicks
).
137 // The first spacing greater than pixelsPerYLabel is what we use.
138 // TODO(danvk): version that works on a log scale.
139 var kmg2
= opts("labelsKMG2");
142 mults
= [1, 2, 4, 8];
146 var scale
, low_val
, high_val
;
147 for (i
= -10; i
< 50; i
++) {
150 base_scale
= pow(16, i
);
152 base_scale
= pow(10, i
);
155 for (j
= 0; j
< mults
.length
; j
++) {
156 scale
= base_scale
* mults
[j
];
157 low_val
= Math
.floor(a
/ scale
) * scale
;
158 high_val
= Math
.ceil(b
/ scale
) * scale
;
159 nTicks
= Math
.abs(high_val
- low_val
) / scale
;
160 spacing
= pixels
/ nTicks
;
161 // wish I could break out of both loops at once...
162 if (spacing
> pixels_per_tick
) break;
164 if (spacing
> pixels_per_tick
) break;
167 // Construct the set of ticks.
168 // Allow reverse y-axis if it's explicitly requested.
169 if (low_val
> high_val
) scale
*= -1;
170 for (i
= 0; i
< nTicks
; i
++) {
171 tickV
= low_val
+ i
* scale
;
172 ticks
.push( {v
: tickV
} );
177 // Add formatted labels to the ticks.
181 if (opts("labelsKMB")) {
183 k_labels
= [ "K", "M", "B", "T", "Q" ];
185 if (opts("labelsKMG2")) {
186 if (k
) Dygraph
.warn("Setting both labelsKMB and labelsKMG2. Pick one!");
188 k_labels
= [ "k", "M", "G", "T", "P", "E", "Z", "Y" ];
189 m_labels
= [ "m", "u", "n", "p", "f", "a", "z", "y" ];
192 var formatter
= opts('axisLabelFormatter');
194 // Add labels to the ticks.
195 for (i
= 0; i
< ticks
.length
; i
++) {
196 if (ticks
[i
].label
!== undefined
) continue; // Use current label.
198 var absTickV
= Math
.abs(tickV
);
199 // TODO(danvk): set granularity to something appropriate here.
200 var label
= formatter(tickV
, 0, opts
, dygraph
);
201 if (k_labels
.length
> 0) {
202 // TODO(danvk): should this be integrated into the axisLabelFormatter?
203 // Round up to an appropriate unit.
204 var n
= pow(k
, k_labels
.length
);
205 for (j
= k_labels
.length
- 1; j
>= 0; j
--, n
/= k
) {
207 label
= Dygraph
.round_(tickV
/ n
, opts('digitsAfterDecimal')) +
213 if(opts("labelsKMG2")){
214 tickV
= String(tickV
.toExponential());
215 if(tickV
.split('e-').length
=== 2 && tickV
.split('e-')[1] >= 3 && tickV
.split('e-')[1] <= 24){
216 if(tickV
.split('e-')[1] % 3 > 0) {
217 label
= Dygraph
.round_(tickV
.split('e-')[0] /
218 pow(10,(tickV
.split('e-')[1] % 3)),
219 opts('digitsAfterDecimal'));
221 label
= Number(tickV
.split('e-')[0]).toFixed(2);
223 label
+= m_labels
[Math
.floor(tickV
.split('e-')[1] / 3) - 1];
226 ticks
[i
].label
= label
;
233 Dygraph
.dateTicker
= function(a
, b
, pixels
, opts
, dygraph
, vals
) {
234 var chosen
= Dygraph
.pickDateTickGranularity(a
, b
, pixels
, opts
);
237 return Dygraph
.getDateAxis(a
, b
, chosen
, opts
, dygraph
);
239 // this can happen if self.width_ is zero.
244 // Time granularity enumeration
245 Dygraph
.SECONDLY
= 0;
246 Dygraph
.TWO_SECONDLY
= 1;
247 Dygraph
.FIVE_SECONDLY
= 2;
248 Dygraph
.TEN_SECONDLY
= 3;
249 Dygraph
.THIRTY_SECONDLY
= 4;
250 Dygraph
.MINUTELY
= 5;
251 Dygraph
.TWO_MINUTELY
= 6;
252 Dygraph
.FIVE_MINUTELY
= 7;
253 Dygraph
.TEN_MINUTELY
= 8;
254 Dygraph
.THIRTY_MINUTELY
= 9;
256 Dygraph
.TWO_HOURLY
= 11;
257 Dygraph
.SIX_HOURLY
= 12;
260 Dygraph
.MONTHLY
= 15;
261 Dygraph
.QUARTERLY
= 16;
262 Dygraph
.BIANNUAL
= 17;
264 Dygraph
.DECADAL
= 19;
265 Dygraph
.CENTENNIAL
= 20;
266 Dygraph
.NUM_GRANULARITIES
= 21;
268 Dygraph
.SHORT_SPACINGS
= [];
269 Dygraph
.SHORT_SPACINGS
[Dygraph
.SECONDLY
] = 1000 * 1;
270 Dygraph
.SHORT_SPACINGS
[Dygraph
.TWO_SECONDLY
] = 1000 * 2;
271 Dygraph
.SHORT_SPACINGS
[Dygraph
.FIVE_SECONDLY
] = 1000 * 5;
272 Dygraph
.SHORT_SPACINGS
[Dygraph
.TEN_SECONDLY
] = 1000 * 10;
273 Dygraph
.SHORT_SPACINGS
[Dygraph
.THIRTY_SECONDLY
] = 1000 * 30;
274 Dygraph
.SHORT_SPACINGS
[Dygraph
.MINUTELY
] = 1000 * 60;
275 Dygraph
.SHORT_SPACINGS
[Dygraph
.TWO_MINUTELY
] = 1000 * 60 * 2;
276 Dygraph
.SHORT_SPACINGS
[Dygraph
.FIVE_MINUTELY
] = 1000 * 60 * 5;
277 Dygraph
.SHORT_SPACINGS
[Dygraph
.TEN_MINUTELY
] = 1000 * 60 * 10;
278 Dygraph
.SHORT_SPACINGS
[Dygraph
.THIRTY_MINUTELY
] = 1000 * 60 * 30;
279 Dygraph
.SHORT_SPACINGS
[Dygraph
.HOURLY
] = 1000 * 3600;
280 Dygraph
.SHORT_SPACINGS
[Dygraph
.TWO_HOURLY
] = 1000 * 3600 * 2;
281 Dygraph
.SHORT_SPACINGS
[Dygraph
.SIX_HOURLY
] = 1000 * 3600 * 6;
282 Dygraph
.SHORT_SPACINGS
[Dygraph
.DAILY
] = 1000 * 86400;
283 Dygraph
.SHORT_SPACINGS
[Dygraph
.WEEKLY
] = 1000 * 604800;
287 * This is a list of human-friendly values at which to show tick marks on a log
288 * scale. It is k * 10^n, where k=1..9 and n=-39..+39, so:
289 * ..., 1, 2, 3, 4, 5, ..., 9, 10, 20, 30, ..., 90, 100, 200, 300, ...
290 * NOTE: this assumes that Dygraph.LOG_SCALE = 10.
292 Dygraph
.PREFERRED_LOG_TICK_VALUES
= function() {
294 for (var power
= -39; power
<= 39; power
++) {
295 var range
= Math
.pow(10, power
);
296 for (var mult
= 1; mult
<= 9; mult
++) {
297 var val
= range
* mult
;
305 * Determine the correct granularity of ticks on a date axis.
307 * @param {Number} a Left edge of the chart (ms)
308 * @param {Number} b Right edge of the chart (ms)
309 * @param {Number} pixels Size of the chart in the relevant dimension (width).
310 * @param {Function} opts Function mapping from option name -> value.
311 * @return {Number} The appropriate axis granularity for this chart. See the
312 * enumeration of possible values in dygraph-tickers.js.
314 Dygraph
.pickDateTickGranularity
= function(a
, b
, pixels
, opts
) {
315 var pixels_per_tick
= opts('pixelsPerLabel');
316 for (var i
= 0; i
< Dygraph
.NUM_GRANULARITIES
; i
++) {
317 var num_ticks
= Dygraph
.numDateTicks(a
, b
, i
);
318 if (pixels
/ num_ticks
>= pixels_per_tick
) {
325 Dygraph
.numDateTicks
= function(start_time
, end_time
, granularity
) {
326 if (granularity
< Dygraph
.MONTHLY
) {
327 // Generate one tick mark for every fixed interval of time.
328 var spacing
= Dygraph
.SHORT_SPACINGS
[granularity
];
329 return Math
.floor(0.5 + 1.0 * (end_time
- start_time
) / spacing
);
331 var year_mod
= 1; // e.g. to only print one point every 10 years.
333 if (granularity
== Dygraph
.QUARTERLY
) num_months
= 3;
334 if (granularity
== Dygraph
.BIANNUAL
) num_months
= 2;
335 if (granularity
== Dygraph
.ANNUAL
) num_months
= 1;
336 if (granularity
== Dygraph
.DECADAL
) { num_months
= 1; year_mod
= 10; }
337 if (granularity
== Dygraph
.CENTENNIAL
) { num_months
= 1; year_mod
= 100; }
339 var msInYear
= 365.2524 * 24 * 3600 * 1000;
340 var num_years
= 1.0 * (end_time
- start_time
) / msInYear
;
341 return Math
.floor(0.5 + 1.0 * num_years
* num_months
/ year_mod
);
345 Dygraph
.getDateAxis
= function(start_time
, end_time
, granularity
, opts
, dg
) {
346 var formatter
= opts("axisLabelFormatter");
350 if (granularity
< Dygraph
.MONTHLY
) {
351 // Generate one tick mark for every fixed interval of time.
352 var spacing
= Dygraph
.SHORT_SPACINGS
[granularity
];
354 // Find a time less than start_time which occurs on a "nice" time boundary
355 // for this granularity.
356 var g
= spacing
/ 1000;
357 var d
= new Date(start_time
);
358 d
.setMilliseconds(0);
360 if (g
<= 60) { // seconds
361 x
= d
.getSeconds(); d
.setSeconds(x
- x
% g
);
365 if (g
<= 60) { // minutes
366 x
= d
.getMinutes(); d
.setMinutes(x
- x
% g
);
371 if (g
<= 24) { // days
372 x
= d
.getHours(); d
.setHours(x
- x
% g
);
377 if (g
== 7) { // one week
378 d
.setDate(d
.getDate() - d
.getDay());
383 start_time
= d
.getTime();
385 for (t
= start_time
; t
<= end_time
; t
+= spacing
) {
387 label
: formatter(new Date(t
), granularity
, opts
, dg
)
391 // Display a tick mark on the first of a set of months of each year.
392 // Years get a tick mark iff y % year_mod == 0. This is useful for
393 // displaying a tick mark once every 10 years, say, on long time scales.
395 var year_mod
= 1; // e.g. to only print one point every 10 years.
397 if (granularity
== Dygraph
.MONTHLY
) {
398 months
= [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 ];
399 } else if (granularity
== Dygraph
.QUARTERLY
) {
400 months
= [ 0, 3, 6, 9 ];
401 } else if (granularity
== Dygraph
.BIANNUAL
) {
403 } else if (granularity
== Dygraph
.ANNUAL
) {
405 } else if (granularity
== Dygraph
.DECADAL
) {
408 } else if (granularity
== Dygraph
.CENTENNIAL
) {
412 Dygraph
.warn("Span of dates is too long");
415 var start_year
= new Date(start_time
).getFullYear();
416 var end_year
= new Date(end_time
).getFullYear();
417 var zeropad
= Dygraph
.zeropad
;
418 for (var i
= start_year
; i
<= end_year
; i
++) {
419 if (i
% year_mod
!== 0) continue;
420 for (var j
= 0; j
< months
.length
; j
++) {
421 var date_str
= i
+ "/" + zeropad(1 + months[j]) + "/01";
422 t
= Dygraph
.dateStrToMillis(date_str
);
423 if (t
< start_time
|| t
> end_time
) continue;
425 label
: formatter(new Date(t
), granularity
, opts
, dg
)
434 // These are set here so that this file can be included after dygraph.js.
435 Dygraph
.DEFAULT_ATTRS
.axes
.x
.ticker
= Dygraph
.dateTicker
;
436 Dygraph
.DEFAULT_ATTRS
.axes
.y
.ticker
= Dygraph
.numericTicks
;
437 Dygraph
.DEFAULT_ATTRS
.axes
.y2
.ticker
= Dygraph
.numericTicks
;