feat: add ndarray/base/rotr90

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Resolves stdlib-js/metr-issue-tracker#203.

Description

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This pull request:

• add ndarray/base/rot90

Related Issues

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This pull request has the following related issues:

• Resolves [RFC]: add ndarray/base/rot90 metr-issue-tracker#203

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Coverage Report

Package	Statements	Branches	Functions	Lines
ndarray/base/rotr90	$\color{green}152/152$ $\color{green}+0.00%$	$\color{green}10/10$ $\color{green}+0.00%$	$\color{green}1/1$ $\color{green}+0.00%$	$\color{green}152/152$ $\color{green}+0.00%$

The above coverage report was generated for the changes in this PR.

[kgryte]

Why did you choose not to support providing a list of dimensions, as done in NumPy?

[kgryte]

It looks like you chose to follow Julia here, but I don't think that was the correct choice within the wider context of packages we should add. My recommendation:

1. Rename this utility to rotlr90 to reflect that we are only rotating the last two dimensions.
2. Add a new package rot90 which allows specifying the two dimensions to rotate.

In principle, the former could simply be a wrapper around the latter.

[kgryte]

Also, I think Julia's behavior is more obvious here for left-right rotation. NumPy's behavior of rotating from the first axis toward the second axis with the default of (0,1) is a bit odd, as the default behavior of rot90 is to rotate counterclockwise, which, IMHO, is the opposite of common user intuition.

So I would update the rotation equivalently. Meaning, k = 1 should be implemented as k = 3 is now, etc.

[kgryte]

Okay. After chatting with ChatGPT about this (link, I want to amend my recommendation:

1. Rename and refactor the utility to rotr90( x, k, writable ) where k > 0 means to rotate clockwise and k < 0 means to rotate counterclockwise. This API should operate on a matrix or stack of matrices.
2. Once merged, create another utility called rotl90( x, k, writable ), which does the reverse of rotr90, with k > 0 means to rotate counterclockwise and k < 0 means to rotate clockwise. This utility will effectively be a very thin wrapper for rotr90( x, -k, writable ), as done in Julia.
3. Create a new rot90( x, dims, k, writable ) utility which allows specifying the plane of rotation. The default behavior of the top-level ndarray/rot90 package should follow NumPy's default semantics, with the exception that the default dimensions should be [ -2, -1 ] (i.e., the last two dimensions).

This approach should satisfy the dual interpretations of rotation. The rot(r|l)90 utilities provide convenience APIs when thinking of matrices as images and the rot90 utility provides an API for thinking of rotations in terms of linear algebra.

[kgryte]

LGTM after clean-up.

[kgryte]

For METR,

review_time: 33 mins