yy-random
yet another javascript random number API with seeded number support
Code Example
const Random = require('yy-random')
// returns a random integer from 0 - 9
Random.get(10)
// returns a random float for 0 - 2
Random.get(2, true)
// changes the generator from Math.random() to a seeded random function
Random.seed(100)
// returns a random integer between 5 - 20 (including 5 and 20)
// this will return the same number each time because of the Random.seed(100) call
Random.range(5, 20)
Installation
include yy-random in your project or add to your workflow
npm i yy-random
Rationale
I use lots of random numbers in my game. I created this library to make it easier to generate the perfect number for as many scenarios as possible. The library has almost complete test code coverage.
API
/**
* generates a seeded number
* @param {number} seed
* @param {object} [options]
* @param {string} [PRNG="alea"] - name of algorithm, see https://github.com/davidbau/seedrandom
* @param {(boolean|string)} [state] - can include the state returned from save()
*/
seed(seed, options) {
/**
* saves the state of the random generator
* can only be used after Random.seed() is called with options.state = true
* @returns {number} state
*/
save() {
/**
* restores the state of the random generator
* @param {number} state
*/
restore(state) {
/**
* changes the generator to use the old Math.sin-based random function
* based on : http://stackoverflow.com/questions/521295/javascript-random-seeds
* (deprecated) Use only for compatibility purposes
* @param {number} seed
*/
seedOld(seed) {
/**
* create a separate random generator using the seed
* @param {number} seed
* @return {object}
*/
separateSeed(seed) {
/**
* resets the random number this.generator to Math.random()
*/
reset() {
/**
* returns a random number using the this.generator between [0, ceiling - 1]
* @param {number} ceiling
* @param {boolean} [useFloat=false]
* @return {number}
*/
get(ceiling, useFloat) {
/**
* returns a random integer between 0 - Number.MAX_SAFE_INTEGER
* @return {number}
*/
getHuge() {
/**
* random number [middle - range, middle + range]
* @param {number} middle
* @param {number} delta
* @param {boolean} [useFloat=false]
* @return {number}
*/
middle(middle, delta, useFloat) {
/**
* random number [start, end]
* @param {number} start
* @param {number} end
* @param {boolean} [useFloat=false] if true, then range is (start, end)--i.e., not inclusive to start and end
* @return {number}
*/
range(start, end, useFloat) {
/**
* an array of random numbers between [start, end]
* @param {number} start
* @param {number} end
* @param {number} count
* @param {boolean} [useFloat=false]
* @return {number[]}
*/
rangeMultiple(start, end, count, useFloat) {
/**
* an array of random numbers between [middle - range, middle + range]
* @param {number} middle
* @param {number} range
* @param {number} count
* @param {boolean} [useFloat=false]
* @return {number[]}
*/
middleMultiple(middle, range, count, useFloat) {
/**
* @param {number} [chance=0.5]
* returns random sign (either +1 or -1)
* @return {number}
*/
sign(chance) {
/**
* tells you whether a random chance was achieved
* @param {number} [percent=0.5]
* @return {boolean}
*/
chance(percent) {
/**
* returns a random angle in radians [0 - 2 * Math.PI)
*/
angle() {
/**
* Shuffle array (either in place or copied)
* from http://stackoverflow.com/questions/2450954/how-to-randomize-shuffle-a-javascript-array
* @param {Array} array
* @param {boolean} [copy=false] whether to shuffle in place (default) or return a new shuffled array
* @return {Array} a shuffled array
*/
shuffle(array, copy) {
/**
* picks a random element from an array
* @param {Array} array
* @return {*}
*/
pick(array, remove) {
/**
* select a random collection of elements from an array
* @param {Array} array
* @param {number} count
* @param {Array} array of selected items
*/
select(array, count) {
/**
* returns a random property from an object
* from http://stackoverflow.com/questions/2532218/pick-random-property-from-a-javascript-object
* @param {object} obj
* @return {*}
*/
property(obj) {
/**
* creates a random set where each entry is a value between [min, max]
* @param {number} min
* @param {number} max
* @param {number} amount of numbers in set
* @param {number[]}
*/
set(min, max, amount) {
/**
* returns a set of numbers with a randomly even distribution (i.e., no overlapping and filling the space)
* @param {number} start position
* @param {number} end position
* @param {number} count of non-start/end points
* @param {boolean} [includeStart=false] includes start point (count++)
* @param {boolean} [includeEnd=false] includes end point (count++)
* @param {boolean} [useFloat=false]
* @param {number[]}
*/
distribution(start, end, count, includeStart, includeEnd, useFloat) {
/**
* returns a random number based on weighted probability between [min, max]
* from http://stackoverflow.com/questions/22656126/javascript-random-number-with-weighted-probability
* @param {number} min value
* @param {number} max value
* @param {number} target for average value
* @param {number} stddev - standard deviation
*/
weightedProbabilityInt(min, max, target, stddev) {
/**
* returns a random number within a circle with a normal distribution
* from https://stackoverflow.com/a/5838055/1955997
* @param {number} x
* @param {number} y
* @param {number} radius
* @param {bool} [float]
* @returns {number[]} [x, y]
*/
circle(x, y, radius, float) {License
MIT License
(c) 2017 YOPEY YOPEY LLC by David Figatner