helper.js
3.96 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
/**
* For testable.
*/
import * as numberUtil from '../util/number';
var roundNumber = numberUtil.round;
/**
* @param {Array.<number>} extent Both extent[0] and extent[1] should be valid number.
* Should be extent[0] < extent[1].
* @param {number} splitNumber splitNumber should be >= 1.
* @param {number} [minInterval]
* @param {number} [maxInterval]
* @return {Object} {interval, intervalPrecision, niceTickExtent}
*/
export function intervalScaleNiceTicks(extent, splitNumber, minInterval, maxInterval) {
var result = {};
var span = extent[1] - extent[0];
var interval = result.interval = numberUtil.nice(span / splitNumber, true);
if (minInterval != null && interval < minInterval) {
interval = result.interval = minInterval;
}
if (maxInterval != null && interval > maxInterval) {
interval = result.interval = maxInterval;
}
// Tow more digital for tick.
var precision = result.intervalPrecision = getIntervalPrecision(interval);
// Niced extent inside original extent
var niceTickExtent = result.niceTickExtent = [
roundNumber(Math.ceil(extent[0] / interval) * interval, precision),
roundNumber(Math.floor(extent[1] / interval) * interval, precision)
];
fixExtent(niceTickExtent, extent);
return result;
}
/**
* @param {number} interval
* @return {number} interval precision
*/
export function getIntervalPrecision(interval) {
// Tow more digital for tick.
return numberUtil.getPrecisionSafe(interval) + 2;
}
function clamp(niceTickExtent, idx, extent) {
niceTickExtent[idx] = Math.max(Math.min(niceTickExtent[idx], extent[1]), extent[0]);
}
// In some cases (e.g., splitNumber is 1), niceTickExtent may be out of extent.
export function fixExtent(niceTickExtent, extent) {
!isFinite(niceTickExtent[0]) && (niceTickExtent[0] = extent[0]);
!isFinite(niceTickExtent[1]) && (niceTickExtent[1] = extent[1]);
clamp(niceTickExtent, 0, extent);
clamp(niceTickExtent, 1, extent);
if (niceTickExtent[0] > niceTickExtent[1]) {
niceTickExtent[0] = niceTickExtent[1];
}
}
export function intervalScaleGetTicks(interval, extent, niceTickExtent, intervalPrecision) {
var ticks = [];
// If interval is 0, return [];
if (!interval) {
return ticks;
}
// Consider this case: using dataZoom toolbox, zoom and zoom.
var safeLimit = 10000;
if (extent[0] < niceTickExtent[0]) {
ticks.push(extent[0]);
}
var tick = niceTickExtent[0];
while (tick <= niceTickExtent[1]) {
ticks.push(tick);
// Avoid rounding error
tick = roundNumber(tick + interval, intervalPrecision);
if (tick === ticks[ticks.length - 1]) {
// Consider out of safe float point, e.g.,
// -3711126.9907707 + 2e-10 === -3711126.9907707
break;
}
if (ticks.length > safeLimit) {
return [];
}
}
// Consider this case: the last item of ticks is smaller
// than niceTickExtent[1] and niceTickExtent[1] === extent[1].
if (extent[1] > (ticks.length ? ticks[ticks.length - 1] : niceTickExtent[1])) {
ticks.push(extent[1]);
}
return ticks;
}