/**
* ??????
* @module echarts/util/number
*/
define(function (require) {
var number = {};
var RADIAN_EPSILON = 1e-4;
function _trim(str) {
return str.replace(/^\s+/, '').replace(/\s+$/, '');
}
/**
* Linear mapping a value from domain to range
* @memberOf module:echarts/util/number
* @param {(number|Array.<number>)} val
* @param {Array.<number>} domain Domain extent domain[0] can be bigger than domain[1]
* @param {Array.<number>} range Range extent range[0] can be bigger than range[1]
* @param {boolean} clamp
* @return {(number|Array.<number>}
*/
number.linearMap = function (val, domain, range, clamp) {
var subDomain = domain[1] - domain[0];
var subRange = range[1] - range[0];
if (subDomain === 0) {
return subRange === 0
? range[0]
: (range[0] + range[1]) / 2;
}
// Avoid accuracy problem in edge, such as
// 146.39 - 62.83 === 83.55999999999999.
// See echarts/test/ut/spec/util/number.js#linearMap#accuracyError
// It is a little verbose for efficiency considering this method
// is a hotspot.
if (clamp) {
if (subDomain > 0) {
if (val <= domain[0]) {
return range[0];
}
else if (val >= domain[1]) {
return range[1];
}
}
else {
if (val >= domain[0]) {
return range[0];
}
else if (val <= domain[1]) {
return range[1];
}
}
}
else {
if (val === domain[0]) {
return range[0];
}
if (val === domain[1]) {
return range[1];
}
}
return (val - domain[0]) / subDomain * subRange + range[0];
};
/**
* Convert a percent string to absolute number.
* Returns NaN if percent is not a valid string or number
* @memberOf module:echarts/util/number
* @param {string|number} percent
* @param {number} all
* @return {number}
*/
number.parsePercent = function(percent, all) {
switch (percent) {
case 'center':
case 'middle':
percent = '50%';
break;
case 'left':
case 'top':
percent = '0%';
break;
case 'right':
case 'bottom':
percent = '100%';
break;
}
if (typeof percent === 'string') {
if (_trim(percent).match(/%$/)) {
return parseFloat(percent) / 100 * all;
}
return parseFloat(percent);
}
return percent == null ? NaN : +percent;
};
/**
* Fix rounding error of float numbers
* @param {number} x
* @return {number}
*/
number.round = function (x) {
// PENDING
return +(+x).toFixed(10);
};
number.asc = function (arr) {
arr.sort(function (a, b) {
return a - b;
});
return arr;
};
/**
* Get precision
* @param {number} val
*/
number.getPrecision = function (val) {
if (isNaN(val)) {
return 0;
}
// It is much faster than methods converting number to string as follows
// var tmp = val.toString();
// return tmp.length - 1 - tmp.indexOf('.');
// especially when precision is low
var e = 1;
var count = 0;
while (Math.round(val * e) / e !== val) {
e *= 10;
count++;
}
return count;
};
/**
* @param {Array.<number>} dataExtent
* @param {Array.<number>} pixelExtent
* @return {number} precision
*/
number.getPixelPrecision = function (dataExtent, pixelExtent) {
var log = Math.log;
var LN10 = Math.LN10;
var dataQuantity = Math.floor(log(dataExtent[1] - dataExtent[0]) / LN10);
var sizeQuantity = Math.round(log(Math.abs(pixelExtent[1] - pixelExtent[0])) / LN10);
return Math.max(
-dataQuantity + sizeQuantity,
0
);
};
// Number.MAX_SAFE_INTEGER, ie do not support.
number.MAX_SAFE_INTEGER = 9007199254740991;
/**
* To 0 - 2 * PI, considering negative radian.
* @param {number} radian
* @return {number}
*/
number.remRadian = function (radian) {
var pi2 = Math.PI * 2;
return (radian % pi2 + pi2) % pi2;
};
/**
* @param {type} radian
* @return {boolean}
*/
number.isRadianAroundZero = function (val) {
return val > -RADIAN_EPSILON && val < RADIAN_EPSILON;
};
/**
* @param {string|Date|number} value
* @return {number} timestamp
*/
number.parseDate = function (value) {
return value instanceof Date
? value
: new Date(
typeof value === 'string'
? value.replace(/-/g, '/')
: Math.round(value)
);
};
/**
* Quantity of a number. e.g. 0.1, 1, 10, 100
* @param {number} val
* @return {number}
*/
number.quantity = function (val) {
return Math.pow(10, Math.floor(Math.log(val) / Math.LN10));
};
// "Nice Numbers for Graph Labels" of Graphic Gems
/**
* find a ?nice? number approximately equal to x. Round the number if round = true, take ceiling if round = false
* The primary observation is that the ?nicest? numbers in decimal are 1, 2, and 5, and all power-of-ten multiples of these numbers.
* @param {number} val
* @param {boolean} round
* @return {number}
*/
number.nice = function (val, round) {
var exp10 = number.quantity(val);
var f = val / exp10; // between 1 and 10
var nf;
if (round) {
if (f < 1.5) { nf = 1; }
else if (f < 2.5) { nf = 2; }
else if (f < 4) { nf = 3; }
else if (f < 7) { nf = 5; }
else { nf = 10; }
}
else {
if (f < 1) { nf = 1; }
else if (f < 2) { nf = 2; }
else if (f < 3) { nf = 3; }
else if (f < 5) { nf = 5; }
else { nf = 10; }
}
return nf * exp10;
};
return number;
});
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