boo1ean/mersenne-twister

Mersenne Twister pseudorandom number generator

Pseudorandom number generator

Mersenne Twister pseudorandom number generator.

Origin source (generator interface was changed)

Algorithm - http://en.wikipedia.org/wiki/Mersenne_twister

Installation

$ npm install mersenne-twister

Usage

var MersenneTwister = require('mersenne-twister');
var generator = new MersenneTwister();

// Generates a random number on [0,1) real interval (same interval as Math.random)
generator.random();

// [0, 4294967295]
generator.random_int();

// [0,1]
generator.random_incl();

// (0,1)
generator.random_excl();

// [0,1) with 53-bit resolution
generator.random_long();

// [0, 2147483647]
generator.random_int31();

Seeding

If you want to use a specific seed in order to get a repeatable random sequence, pass an integer into the constructor:

var generator = new MersenneTwister(123);

and that will always produce the same random sequence.

Also you can do it on existing generator instance:

generator.init_seed(123);

License

See source

mersenne-twister's Issues

Typescript

Hi @boo1ean,
I would like to know if you are interesting in refactor this package to Typescript, I already refactored it in my side. Let me know, if yes, I'll open a PR with the proper changes.

Create interface for full state management

Variables mt and mti appear to fully determine the state of the generator.

I suggest implementing functions get_state and set_state that respectively return and receive a state object containing the keys mt and mt.

For Example:

MersenneTwister.prototype.get_state = function() {
    return {
        mti:this.mti,
        mt:this.mt.slice(),
    }
}

MersenneTwister.prototype.set_state = function(newstate) {
    this.mti = newstate.mti;
    this.mt = newstate.mt.slice();
}
MersenneTwister.prototype.set_state_unsafe = function(newstate) {
    this.mti = newstate.mti;
    this.mt = newstate.mt;
}

This would be useful in situations where it is necessary to revert to an arbitrary midpoint through a random progression. Currently, it is possible just by manually controlling mti and mt, but ideally a user would not need to understand the inner-workings of the mersenne twister in order to manage its state.

Run in nodejs OR browser

Changing the following would allow the same file to be loaded in either nodejs or the browser:

From:

/* These real versions are due to Isaku Wada, 2002/01/09 added */

module.exports = MersenneTwister;

To:

/* These real versions are due to Isaku Wada, 2002/01/09 added */

//Note process should exist only in nodejs, while window exists only in the browser
if(typeof process !== 'undefined' && typeof window === 'undefined')
{
	module.exports = MersenneTwister;
}

If it is not too inconvenient, please apply this change to the repo and update the npm version/package.

mersenne-twister number generation

Hi boo1ean,

I want to use mersenne-twister to generate number between 1-90, as predefined set of start and end number.