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1'use strict'
2
3const deepMap = require('../../utils/collection/deepMap')
4
5function factory (type, config, load, typed) {
6 /**
7 * Test whether a value is zero.
8 * The function can check for zero for types `number`, `BigNumber`, `Fraction`,
9 * `Complex`, and `Unit`.
10 *
11 * The function is evaluated element-wise in case of Array or Matrix input.
12 *
13 * Syntax:
14 *
15 * math.isZero(x)
16 *
17 * Examples:
18 *
19 * math.isZero(0) // returns true
20 * math.isZero(2) // returns false
21 * math.isZero(0.5) // returns false
22 * math.isZero(math.bignumber(0)) // returns true
23 * math.isZero(math.fraction(0)) // returns true
24 * math.isZero(math.fraction(1,3)) // returns false
25 * math.isZero(math.complex('2 - 4i') // returns false
26 * math.isZero(math.complex('0i') // returns true
27 * math.isZero('0') // returns true
28 * math.isZero('2') // returns false
29 * math.isZero([2, 0, -3]') // returns [false, true, false]
30 *
31 * See also:
32 *
33 * isNumeric, isPositive, isNegative, isInteger
34 *
35 * @param {number | BigNumber | Complex | Fraction | Unit | Array | Matrix} x Value to be tested
36 * @return {boolean} Returns true when `x` is zero.
37 * Throws an error in case of an unknown data type.
38 */
39 const isZero = typed('isZero', {
40 'number': function (x) {
41 return x === 0
42 },
43
44 'BigNumber': function (x) {
45 return x.isZero()
46 },
47
48 'Complex': function (x) {
49 return x.re === 0 && x.im === 0
50 },
51
52 'Fraction': function (x) {
53 return x.d === 1 && x.n === 0
54 },
55
56 'Unit': function (x) {
57 return isZero(x.value)
58 },
59
60 'Array | Matrix': function (x) {
61 return deepMap(x, isZero)
62 }
63 })
64
65 return isZero
66}
67
68exports.name = 'isZero'
69exports.factory = factory