esm-seedrandom

    3.0.5 • Public • Published

    esm-seedrandom

    Explicitly seeded random number generator for JavaScript, ported to ES Modules.

    Unit tested for number generator compatability with original seedrandom CommonJS NPM package.

    • Version: 3.0.5
    • Author: David Bau
    • Date: 2019-09-14
    • ES Modules port in 2020-12 by Shane Holloway

    Demo

    GitHub Pages-based Live demo

    Use

    Fast PRNG Algorithms

    PRNG name Period Author BigCrush test results
    prng_alea ~2^116 Baagøe pass all
    prng_xor128 2^128-1 Marsaglia fail MatrixRank and LinearComp
    prng_tychei ~2^127 Neves/Araujo (ChaCha) pass all
    prng_xorwow 2^192-2^32 Marsaglia fail CollisionOver, SimpPoker, and LinearComp
    prng_xor4096 2^4096-2^32 Brent (xorgens) pass all
    prng_xorshift7 2^256-1 Panneton/L'ecuyer pass all
    prng_arc4 ~2^1600 Bau (ARC4) unknown

    To use Johannes Baagøe's extremely fast Alea PRNG:

    // Use alea for Johannes Baagøe's clever and fast floating-point RNG.
    import {prng_alea} from 'esm-seedrandom';
    let myrng = prng_alea('hello.');
    
    // By default provides 32 bits of randomness in a float.
    console.log(myrng());               // Always 0.4783254903741181 for this seed and sequence
    console.log(myrng.quick());         // Always 0.8297006865032017 for this seed and sequence
    
    // Use "double" to get 56 bits of randomness.
    console.log(myrng.double());        // Always 0.4692433053279662 for this seed and sequence
    
    // Use "int32" to get a 32 bit (signed) integer.
    console.log(myrng.int32());         // Always 1350551666 for this seed and sequence

    or direclty from HTML,

    <script type="module">
      import {prng_alea} from '//cdn.jsdelivr.net/npm/esm-seedrandom/esm/alea.min.mjs'
    
      let myrng = prng_alea('an example seed string')
    
      console.log(myrng()); // Always 0.2594452982302755 for this seed and sequence
      console.log(myrng()); // Always 0.8253263409715146 for this seed and sequence
      console.log(myrng()); // Always 0.42280301195569336 for this seed and sequence
    
      // Use "quick" to get only 32 bits of randomness in a float.
      console.log(myrng.quick()); // Always 0.9045045920647681 for this seed and sequence
      console.log(myrng.quick()); // Always 0.7626296668313444 for this seed and sequence
    
      // Use "int32" to get a 32 bit (signed) integer
      console.log(myrng.int32()); // Always 1157605039 for this seed and sequence
      console.log(myrng.int32()); // Always 346379077 for this seed and sequence
    
      console.log(myrng.double()); // Always 0.9541419381134651 for this seed and sequence
      console.log(myrng.double()); // Always 0.7982540860513401 for this seed and sequence
    </script>

    Docs

    See the API docs.

    Overview

    From NodeJS,

    npm install esm-seedrandom

    or in HTML,

    <script type='module'>
      import {prng_alea} from '//cdn.jsdelivr.net/npm/esm-seedrandom/esm/index.min.mjs'
    
      // or use the individual algorithms by module
    
      import {prng_alea} from '//cdn.jsdelivr.net/npm/esm-seedrandom/esm/alea.min.mjs'
      import {prng_xor128} from '//cdn.jsdelivr.net/npm/esm-seedrandom/esm/xor128.min.mjs'
      import {prng_tychei} from '//cdn.jsdelivr.net/npm/esm-seedrandom/esm/tychei.min.mjs'
      import {prng_xorwow} from '//cdn.jsdelivr.net/npm/esm-seedrandom/esm/xorwow.min.mjs'
      import {prng_xor4096} from '//cdn.jsdelivr.net/npm/esm-seedrandom/esm/xor4096.min.mjs'
      import {prng_xorshift7} from '//cdn.jsdelivr.net/npm/esm-seedrandom/esm/xorshift7.min.mjs'
      import {prng_arc4} from '//cdn.jsdelivr.net/npm/esm-seedrandom/esm/arc4.min.mjs'
    </script>

    Saving & Restoring PRNG state

    import {prng_alea} from 'esm-seedrandom';
    
    let rng_first = prng_alea("secret-seed", {state: true});
    let saved_state = rng_first.state()
    for (let j = 0; j < 1e5; ++j)
      rng_first();
    
    // later
    
    let rng_replica = prng_alea("", {state: saved_state});
    for (let j = 0; j < 1e5; ++j)
      rng_replica();

    In normal use the prng is opaque and its internal state cannot be accessed. However, if the state option is provided, the prng gets a state() method that returns a plain object the can be used to reconstruct a prng later in the same state (by passing that saved object back as the state option).

    Unit tests

    Mocha-based live unittests for reproducability and validation of state capture and restore.

    In NodeJS unittests, validation of state snapshot compatability with the original seedrandom CommonJS implementation is performed.

    LICENSE (MIT)

    Copyright 2020 Shane Holloway. (ES Module port) Copyright 2019 David Bau.

    Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

    The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

    Install

    npm i esm-seedrandom

    DownloadsWeekly Downloads

    134

    Version

    3.0.5

    License

    MIT

    Unpacked Size

    11.4 MB

    Total Files

    1134

    Last publish

    Collaborators

    • shanewholloway