Hello!

I noticed that Random constructor just ignores argument if it is not RNG without any error message:

Maybe it will be more helpful to throw Error or raise some console.error message in this case, to not mislead users.

Second thing is that README suggests use following code to specify seed:

import { Random } from 'random'
import seedrandom from 'seedrandom'

const rng = new Random()
const rng2 = new Random(seedrandom('tinykittens'))

And this isn't correct because of that check in constructor.

Best regards,
ProgMiner

Hello.

I'm new to programming.

I really like this random app.

I need to generate a HEX (Hexadecimal) string of specific length.

But I see I didn't find this function random.hex(length, options) in random.

It would be great to be able to generate HEX values ​​of custom length and letter type.

For example:

let get40 = random.hex(40, both); // options: capital, lowercase, both.

console.log(get40); // 0397032E0f12958AC8EC58728018e299e883254b

Thank you for your attention.

I'm just trying to use your module but it seems to require some dependency called esm — I think a better solution might be to just transpile to ES5 compatible code so that users can just require('random') or import 'random' in node and browserify.

uniform-int currently functions by stretching the output range of the RNG into the desired range. However, this is not strictly correct as it depends on the output size of the RNG. For instance, with a small-scale example, if the RNG only outputs 16 bits and we're generating a number from 0 to 5:

>>> collections.Counter(i * 6 // 0xffff for i in range(0xffff))
Counter({0: 10923, 2: 10923, 4: 10923, 1: 10922, 3: 10922, 5: 10922})

We can run a simulation to see the effect of this as well:

const random = require("random")

const hist = new Map();

for (let i = 0; i < 20000000; i++) {
    const n = random.int(0, 5);
    hist.set(n, (hist.get(n) || 0) + 1);
}

and we get:

Map(6) {
  4 => 3334526,
  5 => 3333539,
  3 => 3334684,
  1 => 3331604,
  0 => 3333306,
  2 => 3332341
}

In order to get a truly uniform distribution, the generator needs to instead:

• operate by generating bits with a uniform distribution (it's likely that Math.random will at least be uniform over 64 bits, so it's possible to generate 64 bits at a time).
• generate enough bits to hold the max value
• if the generated number is > max value, discard and try again

https://github.com/python/cpython/blob/8a0d9a6bb77a72cd8b9ece01b7c1163fff28029a/Lib/random.py#L235-L243 has an example of how it works.

Cannot import successfully. How do I solve this?

I'm using it like so.

import random from 'random'

//...

const get = () => {
    const num = random.uniformInt(0, 100)();
    return num;
}

but it shows me this:

ERROR in ./node_modules/random/dist/esm/index.esm.js 1:0-30
Module not found: Error: Can't resolve './random' in 'myprojects\project\node_modules\random\dist\esm'
Did you mean 'random.js'?
BREAKING CHANGE: The request './random' failed to resolve only because it was resolved as fully specified
(probably because the origin is strict EcmaScript Module, e. g. a module with javascript mimetype, a '*.mjs' file, or a '*.js' file where the package.json contains '"type": "module"').
The extension in the request is mandatory for it to be fully specified.
Add the extension to the request.

I tried these but didnt work:

import random from 'random.js'
import random from 'random.ejs'
import random from 'random.esm.js'
import random from 'random.mjs'

Hello!

First of all, thank you so much for your work! :D

I started a fun project that uses your module. Is there any reason why are you not exposing the Random class? I would like to instantiate different Objects that have different seeds and it would be useful to instantiate random generators.

Thank you in advance

While this package is published as standard modules, seedrandom isn't, so this line fails in browsers. See the console error in my attempt at a live demo.

seedrandom hasn't been updated in a long time, so I'm not sure if it's feasible for it to publish modules also.

I have a request: Can the choice() function be enhanced to retrieve more than one option?

random.choices(data: array, choices: number, isUnique: boolean = true)

example:

random.choices([1, true, 'foo'], 3) //return: true, 'foo', 1

random.choices([1, true, 'foo'], 3, false) //return: true, 'foo', 'foo'

I was expecting [0,1] using random.pareto(1). How do I use it exactly? Thank you.

The following typechecks

import { RNGFactory, Random } from 'random';
import seedrandom from 'seedrandom';

RNGFactory(seedrandom('random seed'));

But RNGFactory is not actually exported. Commenting out this line fixes it https://github.com/transitive-bullshit/random/blob/master/src/index.ts#L5-L8

I'm curious why this was necessary in the first place?

Here is my code:

index.ts:

import random from 'random';

const min = 0;
const max = 14206147658

for (let i = 0; i < 100; i = i+1) {
  const randomInt = random.int(min, max);
  console.log(`${i}: random: ${randomInt}`);
}

Here is a sample of my result:

0: random: 727406658
1: random: -579739191
2: random: -42082040
3: random: -915337893
4: random: 1667450201
5: random: 120576257
6: random: -839908019
7: random: 626427272
8: random: 345808248
9: random: 1928860574
10: random: 241466404
...

Why am I getting negative results?

When runing in a browser, with a Content Security Policy (CSP) enabled, which does not allow eval (which is every decent policy), this package breaks the application.

I receive the following error in Chromium:

EvalError: Refused to evaluate a string as JavaScript because 'unsafe-eval' is not an allowed source of script in the following Content Security Policy directive: "default-src 'self'".

    at eval (<anonymous>)
    at seedrandom.js:32
    at Object../node_modules/seedrandom/seedrandom.js (seedrandom.js:25)
    at Object../node_modules/seedrandom/index.js (index.js:51)
    at Object../node_modules/random/dist/rng-factory.js (rng-factory.js:1)
    at Object../node_modules/random/dist/random.js (random.js:4)

It seems that the eval() comes from seedrandom package and it has been fixed a few months ago there:
davidbau/seedrandom#64
davidbau/seedrandom#65

Could you please upgrade seedrandom to the latest version?

Add an argument p for function random.boolean(), that determines the probability for returning true.

I expected this module to return the same sequence of random numbers if seeded with the same value. But it seems completely unpredictable. I'm I missing something?

const rng = random.clone(seed).uniform();

rng();
rng();
rng();

I would've expected the three rnd() calls to return the same random numbers every time.

I have some JS code, run in node, which was working in 2.2 and now is not. Previously I had:

const random = require('random')
...
const power = random.normal(27.545, 2.182)
...
const v = power()

Now I get

Uncaught TypeError: random.normal is not a function

So I changed to

const random = require('random').default

but now

> power()
Uncaught TypeError: Cannot read property 'next' of undefined
    at Random.next (D:\temp\ser\node_modules\random\dist\random.js:56:31)
    at exports.default (D:\temp\ser\node_modules\random\dist\distributions\normal.js:9:24)

so I had to add

random.use(Math.random)

as part of the initialization.

Please could you advise: Am I doing the right thing? It would be great if this could make it into the docs. I assume this all works as per the docs in Typescript but I am not allowed to use that at the moment.

Hi!

First, thanks for this super cool library.

I just ran into an issue which may just be an issue of the documentation.

When working with seeds, I expected new Random(seedrandom('tinykittens')) to work the same as random.use(seedrandom('tinykittens')) or random.clone(seedrandom('tinykittens')).

But appearently new Random doesn't seed correctly?

console.log('rng test random..')
for (let i=0; i<3; ++i) {
	const prng = new Random(seedrandom('my-seed'))
	console.log(prng.float())
}
// =>
// 0.6724578711199012
// 0.014330871501025522
// 0.16677254682291287

If this is expected behaviour then I think the documentation should be adjusted near the text You can also instantiate a fresh instance of Random.

bernoulli()
binomial()
geometric()
irwinHall()
bates()
pareto()

all throw errors for all inputs, including defaults.

For example:

// Running this
const random = require('random');
const foo = random.bernoulli(0.4);
foo();

// results in
Error: invalid number of arguments to "ow"
    at Object.apply (C:\Users\Andy.Steinberg\Code\test\node_modules\ow-lite\index.js:95:15)
    at exports.default (C:\Users\Andy.Steinberg\Code\test\node_modules\random\dist\distributions\bernoulli.js:16:52)
    at Random.bernoulli (C:\Users\Andy.Steinberg\Code\test\node_modules\random\dist\random.js:369:38)
    at Object.<anonymous> (C:\Users\Andy.Steinberg\Code\test\tester.js:3:20)
    at Module._compile (internal/modules/cjs/loader.js:689:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:742:12)

All of the listed functions result in the same error.

When I try to compile the code from the example using typescript

import { Random } from 'random'
import seedrandom from 'seedrandom'

const rng = new Random()
const rng2 = new Random(seedrandom('tinykittens'))

I get the following error
TS2345: Argument of type 'PRNG' is not assignable to parameter of type 'RNG'.

Hello beautiful software peoples,

imho, JavaScript has been in sore need of a rock solid random module for some time. I tried to find something robust and comprehensive ala boost::random, but the closest I could find were d3-random and seedrandom.

After @rcombs generously donated the npm module random to me, I wanted to try and set a baseline for the API and functionality that exists in this repo today. It's my hope that this will grow, but to get there I think it's important to ask for feedback from the community early on.

I'd like to extend an open invitation to anyone who sees the potential in this module to elicit feedback and/or join as collaborators.

To be clear, I definitely still see a lot of value in one-off modules like random-int and random-normal for the 95% use cases, but I think having a common core for supporting more advanced scenarios will be really useful in promoting scientific computing with JavaScript.

I expected that after setting the same seed, the behavior of both clones would be the same. Unfortunately the following test fails.

import random from "random"

describe('random', () => {
  it('should be predictable', () => {
    const rand1 = random.clone("abc");
    const rand2 = random.clone("abc");
    
    expect(rand1.float()).toEqual(rand2.float());
  });
});

Am I using clone incorrectly?

I'm pretty close to the example from the readme:

...
// create a new independent random number generator (uses seedrandom under the hood)
const rng = random.clone('my-new-seed')
...

Using 3.0.3 I see an error with import random from "random" in a Create React App project.
It says:

./node_modules/random/dist/esm/index.js
Module not found: Can't resolve './random' in './node_modules/random/dist/esm'

I've double checked: there is an index.js there, it tries to require('./random').default but fails because there isn't any random.js file in there :(

I believe it might be connected to #19

I've tried on multiple versions, and random.uniform and random.normal do not return numbers, but return [Function].

Just like python random, making random.choice is a pretty good thing. just for a simplicity.

Example :
array : ["a", "b"]
Instead of doing

array[random.int(0,1)] // return "a"

isn't it better if you could do :

random.choice(array) // return "a"

I know some of you'll like "you can make it yourself". But isn't this why this module created?

Currently, you have to do this:

const random = require('random')
random.uniform() // [ 0, 1 )

But it would be nice to also support this syntax:

const random = require('random')
random() // [ 0, 1 )

This is possible, however, the implementation is pretty hacky and uses Object.setPrototypeOf which MDN explicitly warns against using for performance reasons.

References:

• stackoverflow thread
• callable-instance

Seemingly fairly easy to break..

const random = require('random');

let mean = 300
let sd = 100

let res = 1
let counter = 0;
while (res>0) {
    const s = random.normal(mean, sd)
     res = Math.round(s())
     counter = counter+1;
}
console.log("broke after num tries:", counter)

Hi! I need help for install package. During installation I get this error :

> node postinstall || echo "ignore"

In riga:1 car:18
+ node postinstall || echo "ignore"
+                  ~~
Il token '||' non è un separatore di istruzioni valido in questa versione.     
    + CategoryInfo          : ParserError: (:) [], 
ParentContainsErrorRecordException
    + FullyQualifiedErrorId : InvalidEndOfLine
 
[            ......] \ postinstall: info lifecycle [email protected]~postinstall: 
[            ......] \ postinstall: info lifecycle [email protected]~postinstall: 
[            ......] \ postinstall: info lifecycle [email protected]~postinstall: 
[            ......] \ postinstall: info lifecycle [email protected]~postinstall: 
[            ......] \ postinstall: info lifecycle [email protected]~postinstall: 
[            ......] \ postinstall: info lifecycle [email protected]~postinstall: 
npm WARN optional SKIPPING OPTIONAL DEPENDENCY: [email protected] (node_modules\fsevents):
npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for [email protected]: wanted {"os":"darwin","arch":"any"} (current: {"os":"win32","arch":"x64"})

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! [email protected] postinstall: `node postinstall || echo "ignore"`       
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the [email protected] postinstall script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\sdelg\AppData\Roaming\npm-cache\_logs\2020-04-20T09_12_37_454Z-debug.log

I have already tried to reinstall nodeJS, delete node_modules and package-lock.json and redo npm install
Do you have any idea?