1 | import { factory } from '../../utils/factory'
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2 | import { isMatrix } from '../../utils/is'
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3 | import { createRng } from './util/seededRNG'
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4 | import { randomMatrix } from './util/randomMatrix'
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5 |
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6 | const name = 'random'
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7 | const dependencies = ['typed', 'config', '?on']
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8 |
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9 | export const createRandom = /* #__PURE__ */ factory(name, dependencies, ({ typed, config, on }) => {
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10 | // seeded pseudo random number generator
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11 | let rng = createRng(config.randomSeed)
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12 |
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13 | if (on) {
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14 | on('config', function (curr, prev) {
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15 | if (curr.randomSeed !== prev.randomSeed) {
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16 | rng = createRng(curr.randomSeed)
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17 | }
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18 | })
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19 | }
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20 |
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21 | /**
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22 | * Return a random number larger or equal to `min` and smaller than `max`
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23 | * using a uniform distribution.
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24 | *
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25 | * Syntax:
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26 | *
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27 | * math.random() // generate a random number between 0 and 1
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28 | * math.random(max) // generate a random number between 0 and max
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29 | * math.random(min, max) // generate a random number between min and max
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30 | * math.random(size) // generate a matrix with random numbers between 0 and 1
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31 | * math.random(size, max) // generate a matrix with random numbers between 0 and max
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32 | * math.random(size, min, max) // generate a matrix with random numbers between min and max
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33 | *
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34 | * Examples:
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35 | *
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36 | * math.random() // returns a random number between 0 and 1
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37 | * math.random(100) // returns a random number between 0 and 100
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38 | * math.random(30, 40) // returns a random number between 30 and 40
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39 | * math.random([2, 3]) // returns a 2x3 matrix with random numbers between 0 and 1
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40 | *
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41 | * See also:
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42 | *
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43 | * randomInt, pickRandom
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44 | *
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45 | * @param {Array | Matrix} [size] If provided, an array or matrix with given
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46 | * size and filled with random values is returned
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47 | * @param {number} [min] Minimum boundary for the random value, included
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48 | * @param {number} [max] Maximum boundary for the random value, excluded
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49 | * @return {number | Array | Matrix} A random number
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50 | */
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51 | return typed(name, {
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52 | '': () => _random(0, 1),
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53 | number: (max) => _random(0, max),
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54 | 'number, number': (min, max) => _random(min, max),
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55 | 'Array | Matrix': (size) => _randomMatrix(size, 0, 1),
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56 | 'Array | Matrix, number': (size, max) => _randomMatrix(size, 0, max),
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57 | 'Array | Matrix, number, number': (size, min, max) => _randomMatrix(size, min, max)
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58 | })
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59 |
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60 | function _randomMatrix (size, min, max) {
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61 | const res = randomMatrix(size.valueOf(), () => _random(min, max))
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62 | return isMatrix(size) ? size.create(res) : res
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63 | }
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64 |
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65 | function _random (min, max) {
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66 | return min + rng() * (max - min)
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67 | }
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68 | })
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69 |
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70 | // number only implementation of random, no matrix support
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71 | // TODO: there is quite some duplicate code in both createRandom and createRandomNumber, can we improve that?
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72 | export const createRandomNumber = /* #__PURE__ */ factory(name, ['typed', 'config', '?on'], ({ typed, config, on, matrix }) => {
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73 | // seeded pseudo random number generator1
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74 | let rng = createRng(config.randomSeed)
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75 |
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76 | if (on) {
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77 | on('config', function (curr, prev) {
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78 | if (curr.randomSeed !== prev.randomSeed) {
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79 | rng = createRng(curr.randomSeed)
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80 | }
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81 | })
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82 | }
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83 |
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84 | return typed(name, {
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85 | '': () => _random(0, 1),
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86 | number: (max) => _random(0, max),
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87 | 'number, number': (min, max) => _random(min, max)
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88 | })
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89 |
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90 | function _random (min, max) {
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91 | return min + rng() * (max - min)
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92 | }
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93 | })
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