https://github.com/philihp/pcg

A functional implementation of the PCG family random number generators, written in TypeScript.
https://github.com/philihp/pcg

functional-programming random-generation

Last synced: 26 days ago
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A functional implementation of the PCG family random number generators, written in TypeScript.

• Host: GitHub
• URL: https://github.com/philihp/pcg
• Owner: philihp
• License: mit
• Created: 2023-02-06T09:58:57.000Z (almost 2 years ago)
• Default Branch: main
• Last Pushed: 2024-12-07T04:38:53.000Z (about 1 month ago)
• Last Synced: 2024-12-07T05:23:01.603Z (about 1 month ago)
• Topics: functional-programming, random-generation
• Language: TypeScript
• Homepage: https://www.npmjs.com/package/pcg
• Size: 187 KB
• Stars: 3
• Watchers: 1
• Forks: 0
• Open Issues: 10
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# pcg

[![Version](https://img.shields.io/npm/v/pcg.svg)](https://www.npmjs.com/package/pcg)

[![Tests](https://github.com/philihp/pcg/actions/workflows/tests.yml/badge.svg)](https://github.com/philihp/pcg/actions/workflows/tests.yml)

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![Downloads](https://img.shields.io/npm/dt/pcg)

![License](https://img.shields.io/npm/l/pcg)

A functional implementation of the [PCG family random number generators](), written in JavaScript.

[PCG family random number generators]: http://pcg-random.org

## Getting started

To achieve frictionless reproducibility of random output results, immutable objects are used throughout the project.

First, seed a PCG state. A stream ID specifies _which_ unique periodic series of entropy to use. The state specifies _where_ in that series we start.

```

import { createPcg32 } from 'pcg'

const advancedOptions = {}

const initState = 42

const initStreamId = 54

const state0 = createPcg32(advancedOptions, initState, initStreamId)

```

After that, random outputs can be generated by calling appropriate functions as shown below:

```js

import { nextState, prevState, randomInt, randomList } from 'pcg'

const randomUint32 = randomInt(0, 2 ** 32 - 1)

const [value, nextState] = randomUint32(state0)

const listLength = 3

const listItemRng = randomUint32

const [[v1, state1], [v2, state2], [v3, state3]] = randomList(listLength, listItemRng, state0)

```

In this above example, `value === v1`, and `nextState === state1`

## Thanks

- [@kripod](https://github.com/kripod/), who wrote the original [`pcg.js`](https://github.com/kripod/pcg.js)