echarts
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A powerful charting and visualization library for browser
468 lines (420 loc) • 15 kB
JavaScript
/**
* 数值处理模块
* @module echarts/util/number
*/
define(function (require) {
var zrUtil = require('zrender/core/util');
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;
};
/**
* (1) Fix rounding error of float numbers.
* (2) Support return string to avoid scientific notation like '3.5e-7'.
*
* @param {number} x
* @param {number} [precision]
* @param {boolean} [returnStr]
* @return {number|string}
*/
number.round = function (x, precision, returnStr) {
if (precision == null) {
precision = 10;
}
// Avoid range error
precision = Math.min(Math.max(0, precision), 20);
x = (+x).toFixed(precision);
return returnStr ? x : +x;
};
number.asc = function (arr) {
arr.sort(function (a, b) {
return a - b;
});
return arr;
};
/**
* Get precision
* @param {number} val
*/
number.getPrecision = function (val) {
val = +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 {string|number} val
* @return {number}
*/
number.getPrecisionSafe = function (val) {
var str = val.toString();
// Consider scientific notation: '3.4e-12' '3.4e+12'
var eIndex = str.indexOf('e');
if (eIndex > 0) {
var precision = +str.slice(eIndex + 1);
return precision < 0 ? -precision : 0;
}
else {
var dotIndex = str.indexOf('.');
return dotIndex < 0 ? 0 : str.length - 1 - dotIndex;
}
};
/**
* Minimal dicernible data precisioin according to a single pixel.
*
* @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);
// toFixed() digits argument must be between 0 and 20.
var precision = Math.min(Math.max(-dataQuantity + sizeQuantity, 0), 20);
return !isFinite(precision) ? 20 : precision;
};
/**
* Get a data of given precision, assuring the sum of percentages
* in valueList is 1.
* The largest remainer method is used.
* https://en.wikipedia.org/wiki/Largest_remainder_method
*
* @param {Array.<number>} valueList a list of all data
* @param {number} idx index of the data to be processed in valueList
* @param {number} precision integer number showing digits of precision
* @return {number} percent ranging from 0 to 100
*/
number.getPercentWithPrecision = function (valueList, idx, precision) {
if (!valueList[idx]) {
return 0;
}
var sum = zrUtil.reduce(valueList, function (acc, val) {
return acc + (isNaN(val) ? 0 : val);
}, 0);
if (sum === 0) {
return 0;
}
var digits = Math.pow(10, precision);
var votesPerQuota = zrUtil.map(valueList, function (val) {
return (isNaN(val) ? 0 : val) / sum * digits * 100;
});
var targetSeats = digits * 100;
var seats = zrUtil.map(votesPerQuota, function (votes) {
// Assign automatic seats.
return Math.floor(votes);
});
var currentSum = zrUtil.reduce(seats, function (acc, val) {
return acc + val;
}, 0);
var remainder = zrUtil.map(votesPerQuota, function (votes, idx) {
return votes - seats[idx];
});
// Has remainding votes.
while (currentSum < targetSeats) {
// Find next largest remainder.
var max = Number.NEGATIVE_INFINITY;
var maxId = null;
for (var i = 0, len = remainder.length; i < len; ++i) {
if (remainder[i] > max) {
max = remainder[i];
maxId = i;
}
}
// Add a vote to max remainder.
++seats[maxId];
remainder[maxId] = 0;
++currentSum;
}
return seats[idx] / digits;
};
// 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;
};
var TIME_REG = /^(?:(\d{4})(?:[-\/](\d{1,2})(?:[-\/](\d{1,2})(?:[T ](\d{1,2})(?::(\d\d)(?::(\d\d)(?:[.,](\d+))?)?)?(Z|[\+\-]\d\d:?\d\d)?)?)?)?)?$/; // jshint ignore:line
/**
* @return {number} in minutes
*/
number.getTimezoneOffset = function () {
return (new Date()).getTimezoneOffset();
};
/**
* @param {string|Date|number} value These values can be accepted:
* + An instance of Date, represent a time in its own time zone.
* + Or string in a subset of ISO 8601, only including:
* + only year, month, date: '2012-03', '2012-03-01', '2012-03-01 05', '2012-03-01 05:06',
* + separated with T or space: '2012-03-01T12:22:33.123', '2012-03-01 12:22:33.123',
* + time zone: '2012-03-01T12:22:33Z', '2012-03-01T12:22:33+8000', '2012-03-01T12:22:33-05:00',
* all of which will be treated as local time if time zone is not specified
* (see <https://momentjs.com/>).
* + Or other string format, including (all of which will be treated as loacal time):
* '2012', '2012-3-1', '2012/3/1', '2012/03/01',
* '2009/6/12 2:00', '2009/6/12 2:05:08', '2009/6/12 2:05:08.123'
* + a timestamp, which represent a time in UTC.
* @return {Date} date
*/
number.parseDate = function (value) {
if (value instanceof Date) {
return value;
}
else if (typeof value === 'string') {
// Different browsers parse date in different way, so we parse it manually.
// Some other issues:
// new Date('1970-01-01') is UTC,
// new Date('1970/01/01') and new Date('1970-1-01') is local.
// See issue #3623
var match = TIME_REG.exec(value);
if (!match) {
// return Invalid Date.
return new Date(NaN);
}
var timezoneOffset = number.getTimezoneOffset();
var timeOffset = !match[8]
? 0
: match[8].toUpperCase() === 'Z'
? timezoneOffset
: +match[8].slice(0, 3) * 60 + timezoneOffset;
// match[n] can only be string or undefined.
// But take care of '12' + 1 => '121'.
return new Date(
+match[1],
+(match[2] || 1) - 1,
+match[3] || 1,
+match[4] || 0,
+(match[5] || 0) - timeOffset,
+match[6] || 0,
+match[7] || 0
);
}
else if (value == null) {
return new Date(NaN);
}
return new Date(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, quantityExponent(val));
};
function quantityExponent(val) {
return Math.floor(Math.log(val) / Math.LN10);
}
/**
* 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.
*
* See "Nice Numbers for Graph Labels" of Graphic Gems.
*
* @param {number} val Non-negative value.
* @param {boolean} round
* @return {number}
*/
number.nice = function (val, round) {
var exponent = quantityExponent(val);
var exp10 = Math.pow(10, exponent);
var f = val / exp10; // 1 <= f < 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; }
}
val = nf * exp10;
// Fix 3 * 0.1 === 0.30000000000000004 issue (see IEEE 754).
// 20 is the uppper bound of toFixed.
return exponent >= -20 ? +val.toFixed(exponent < 0 ? -exponent : 0) : val;
};
/**
* Order intervals asc, and split them when overlap.
* expect(numberUtil.reformIntervals([
* {interval: [18, 62], close: [1, 1]},
* {interval: [-Infinity, -70], close: [0, 0]},
* {interval: [-70, -26], close: [1, 1]},
* {interval: [-26, 18], close: [1, 1]},
* {interval: [62, 150], close: [1, 1]},
* {interval: [106, 150], close: [1, 1]},
* {interval: [150, Infinity], close: [0, 0]}
* ])).toEqual([
* {interval: [-Infinity, -70], close: [0, 0]},
* {interval: [-70, -26], close: [1, 1]},
* {interval: [-26, 18], close: [0, 1]},
* {interval: [18, 62], close: [0, 1]},
* {interval: [62, 150], close: [0, 1]},
* {interval: [150, Infinity], close: [0, 0]}
* ]);
* @param {Array.<Object>} list, where `close` mean open or close
* of the interval, and Infinity can be used.
* @return {Array.<Object>} The origin list, which has been reformed.
*/
number.reformIntervals = function (list) {
list.sort(function (a, b) {
return littleThan(a, b, 0) ? -1 : 1;
});
var curr = -Infinity;
var currClose = 1;
for (var i = 0; i < list.length;) {
var interval = list[i].interval;
var close = list[i].close;
for (var lg = 0; lg < 2; lg++) {
if (interval[lg] <= curr) {
interval[lg] = curr;
close[lg] = !lg ? 1 - currClose : 1;
}
curr = interval[lg];
currClose = close[lg];
}
if (interval[0] === interval[1] && close[0] * close[1] !== 1) {
list.splice(i, 1);
}
else {
i++;
}
}
return list;
function littleThan(a, b, lg) {
return a.interval[lg] < b.interval[lg]
|| (
a.interval[lg] === b.interval[lg]
&& (
(a.close[lg] - b.close[lg] === (!lg ? 1 : -1))
|| (!lg && littleThan(a, b, 1))
)
);
}
};
/**
* parseFloat NaNs numeric-cast false positives (null|true|false|"")
* ...but misinterprets leading-number strings, particularly hex literals ("0x...")
* subtraction forces infinities to NaN
*
* @param {*} v
* @return {boolean}
*/
number.isNumeric = function (v) {
return v - parseFloat(v) >= 0;
};
return number;
});