sindresorhus / randoma

User-friendly pseudorandom number generator (PRNG)

randoma

User-friendly pseudorandom number generator (PRNG)

This is not cryptographically secure.

“Pull request welcome” for additional commonly used random methods.

Install

npm install randoma

Usage

import Randoma from 'randoma';

const random = new Randoma({seed: 10});

random.integer();
//=> 2027521326

random.integer();
//=> 677268843


(new Randoma({seed: '🦄'}).integer());
//=> 1659974344

(new Randoma({seed: '🦄'}).integer());
//=> 1659974344

API

const random = new Randoma(options)

options

Type: object

seed

Required
Type: string | number

Initialization seed.

Multiple instances of Randoma with the same seed will generate the same random numbers.

random.integer()

random.integerInRange(minimum, maximum)

random.float()

random.floatInRange(minimum, maximum)

random.boolean()

random.arrayItem(array)

random.date()

random.dateInRange(startDate, endDate)

random.color(saturation?)

Returns a random aesthetically pleasing color as a color object.

random.color(0.5).hex().toString()
//=> '#AAF2B0'

saturation

Type: number
Default: 0.5

A percentage in the range 0...1.

Randoma.seed()

Returns a random seed you could use in the seed option if you for some reason don't want deterministic randomness.

Related

• park-miller - Park-Miller pseudorandom number generator (PRNG)

randoma's Issues

`color` returns the same first colors for majority of seeds

I'm making this issue as I'm not too sure what to actually do about this - it feels like a bug, but at the same time I know that b/c it's generating a color that's also pleasing and psudorandom the pool of possible colors is greatly reduced :/

Anyway, the distribution of random colors is such that the range of possible colors returned for the first color of a seed is greatly reduced lower than further calls to color:

const tColors = (seeds: number, times: number) => {
  const colors = [];

  for (let seed = 0; seed < seeds; seed++) {
    const gen = new Randoma({ seed });

    for (let i = 0; i < times; i++) {
      gen.color();
    }

    colors.push(gen.color());
  }

  return colors.map(color => color.hex());
};

const stats = () => {
  const results = [];

  for (let i = 0; i < 10; i++) {
    results.push(new Set(tColors(100000, i)).size);
  }

  console.log(results.join('\n'));
};

stats();

Give me:

58
726
627
726
726
726
726
726
726
726

Also, the max number of colors generatable seems to be 726.