feat(math): Add distribution functions.

[retraigo]

This PR adds two functions under the math module.

uniformRange generates an array of numbers uniformly distributed between a range in ascending order.

normalDistribution generates an array of numbers normally distributed around a mean in random order.

Tests have been written under the distributions_test.ts file.

[CLAassistant]

All committers have signed the CLA.

[kt3k]

I think this should throw TypeError instead of returning empty array

[retraigo]

Made it throw a TypeError in the latest commit.

[kt3k]

@retraigo Do you have any image about the scope of math module? What kind of items do you suggest we should add in math module?

[retraigo]

@retraigo Do you have any image about the scope of math module? What kind of items do you suggest we should add in math module?

Finding math-related JS/TS code on the internet is a really tedious process. There are only a few math-related modules like mathjs out there. Having a standard, third-party-dependency-free math module for Deno would be great.

It could support any math-related stuff that makes sense to do in JavaScript like,

• Range generation (like the python range())
• ndarrays (a stricter version that involves a private variable maybe?)
• Gamma
• Complex numbers
  or even some basic calculus.

But IMO it shouldn't contain math that operates on a large amount of data (like regression analysis, matrices, etc). Not because they're a bad feature, but they'd be making devs choose them over actually performant third-party modules that use native code.

[cjihrig]

The CI is looking pretty red after the last set of changes.

[kt3k]

Looks like this now should use assertThrows to check it throws TypeError

[kt3k]

@retraigo Thanks for many suggestions!

ndarrays (a stricter version that involves a private variable maybe?)

Is it like ndarrays in numpy? What does stricter version mean?

Gamma

Can you elaborate? What is the use case of this?

Complex numbers or even some basic calculus.

This sounds like common needs for math calculation to me.

Range generation (like the python range())

There's Number.range proposal (stage 1). Maybe we should follow their API if we add it.

But IMO it shouldn't contain math that operates on a large amount of data (like regression analysis, matrices, etc). Not because they're a bad feature, but they'd be making devs choose them over actually performant third-party modules that use native code.

I agree with this. We shouldn't compete with/re-invent something like tensorflow.js

[retraigo]

Is it like ndarrays in numpy? What does stricter version mean?
I meant how you can have ndarrays by just nesting arrays inside each other. A stricter version as in, forcing types and dimensions.

Gamma
Can you elaborate? What is the use case of this?
Complex numbers or even some basic calculus.
This sounds like common needs for math calculation to me.
Maybe they are a bit too much. I was just listing common things people require math libraries for.

There's Number.range proposal (stage 1). Maybe we should follow their API if we add it.
I didn't know a proposal existed for that. It does sound cool.

[kt3k]

We discussed this PR internally, and we are worried about the scope of std/math being too vague at this point. We'd appreciate if you create your own math library in deno.land/x as a 3rd party module, and collect some use cases first, but we don't think accepting random items one by one in std/math is a good idea.

[cjihrig]

I'm going to close this per #2774 (comment), but please do create a module on deno.land/x and iterate on it. We can revisit this after a while.