echarts
Version:
A powerful charting and visualization library for browser
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JavaScript
/**
* Interval scale
* @module echarts/scale/Interval
*/
define(function (require) {
var numberUtil = require('../util/number');
var formatUtil = require('../util/format');
var Scale = require('./Scale');
var helper = require('./helper');
var roundNumber = numberUtil.round;
/**
* @alias module:echarts/coord/scale/Interval
* @constructor
*/
var IntervalScale = Scale.extend({
type: 'interval',
_interval: 0,
_intervalPrecision: 2,
setExtent: function (start, end) {
var thisExtent = this._extent;
//start,end may be a Number like '25',so...
if (!isNaN(start)) {
thisExtent[0] = parseFloat(start);
}
if (!isNaN(end)) {
thisExtent[1] = parseFloat(end);
}
},
unionExtent: function (other) {
var extent = this._extent;
other[0] < extent[0] && (extent[0] = other[0]);
other[1] > extent[1] && (extent[1] = other[1]);
// unionExtent may called by it's sub classes
IntervalScale.prototype.setExtent.call(this, extent[0], extent[1]);
},
/**
* Get interval
*/
getInterval: function () {
return this._interval;
},
/**
* Set interval
*/
setInterval: function (interval) {
this._interval = interval;
// Dropped auto calculated niceExtent and use user setted extent
// We assume user wan't to set both interval, min, max to get a better result
this._niceExtent = this._extent.slice();
this._intervalPrecision = helper.getIntervalPrecision(interval);
},
/**
* @return {Array.<number>}
*/
getTicks: function () {
return helper.intervalScaleGetTicks(
this._interval, this._extent, this._niceExtent, this._intervalPrecision
);
},
/**
* @return {Array.<string>}
*/
getTicksLabels: function () {
var labels = [];
var ticks = this.getTicks();
for (var i = 0; i < ticks.length; i++) {
labels.push(this.getLabel(ticks[i]));
}
return labels;
},
/**
* @param {number} data
* @param {Object} [opt]
* @param {number|string} [opt.precision] If 'auto', use nice presision.
* @param {boolean} [opt.pad] returns 1.50 but not 1.5 if precision is 2.
* @return {string}
*/
getLabel: function (data, opt) {
if (data == null) {
return '';
}
var precision = opt && opt.precision;
if (precision == null) {
precision = numberUtil.getPrecisionSafe(data) || 0;
}
else if (precision === 'auto') {
// Should be more precise then tick.
precision = this._intervalPrecision;
}
// (1) If `precision` is set, 12.005 should be display as '12.00500'.
// (2) Use roundNumber (toFixed) to avoid scientific notation like '3.5e-7'.
data = roundNumber(data, precision, true);
return formatUtil.addCommas(data);
},
/**
* Update interval and extent of intervals for nice ticks
*
* @param {number} [splitNumber = 5] Desired number of ticks
* @param {number} [minInterval]
*/
niceTicks: function (splitNumber, minInterval) {
splitNumber = splitNumber || 5;
var extent = this._extent;
var span = extent[1] - extent[0];
if (!isFinite(span)) {
return;
}
// User may set axis min 0 and data are all negative
// FIXME If it needs to reverse ?
if (span < 0) {
span = -span;
extent.reverse();
}
var result = helper.intervalScaleNiceTicks(extent, splitNumber, minInterval);
this._intervalPrecision = result.intervalPrecision;
this._interval = result.interval;
this._niceExtent = result.niceTickExtent;
},
/**
* Nice extent.
* @param {Object} opt
* @param {number} [opt.splitNumber = 5] Given approx tick number
* @param {boolean} [opt.fixMin=false]
* @param {boolean} [opt.fixMax=false]
* @param {boolean} [opt.minInterval=false]
*/
niceExtent: function (opt) {
var extent = this._extent;
// If extent start and end are same, expand them
if (extent[0] === extent[1]) {
if (extent[0] !== 0) {
// Expand extent
var expandSize = extent[0];
// In the fowllowing case
// Axis has been fixed max 100
// Plus data are all 100 and axis extent are [100, 100].
// Extend to the both side will cause expanded max is larger than fixed max.
// So only expand to the smaller side.
if (!opt.fixMax) {
extent[1] += expandSize / 2;
extent[0] -= expandSize / 2;
}
else {
extent[0] -= expandSize / 2;
}
}
else {
extent[1] = 1;
}
}
var span = extent[1] - extent[0];
// If there are no data and extent are [Infinity, -Infinity]
if (!isFinite(span)) {
extent[0] = 0;
extent[1] = 1;
}
this.niceTicks(opt.splitNumber, opt.minInterval);
// var extent = this._extent;
var interval = this._interval;
if (!opt.fixMin) {
extent[0] = roundNumber(Math.floor(extent[0] / interval) * interval);
}
if (!opt.fixMax) {
extent[1] = roundNumber(Math.ceil(extent[1] / interval) * interval);
}
}
});
/**
* @return {module:echarts/scale/Time}
*/
IntervalScale.create = function () {
return new IntervalScale();
};
return IntervalScale;
});