[RFC]: add `stats/incr/nanmvmr`

[kgryte]

Description

This RFC proposes adding a new package to the stats/incr/* namespace: @stdlib/stats/incr/nanmvmr.

This package is similar to @stdlib/stats/incr/mvmr, except that it performs special handling of NaN values.

Key Points

When implementing this package, you'll need to do the following:

Create package files

To see examples of similar packages, see @stdlib/stats/incr/mvmr (propagates NaN values) and @stdlib/stats/incr/nansum (wraps a NaN propagating accumulator and skips NaN values).

In particular notice how nansum is a thin wrapper around sum. In most cases, this is what we are looking for.

While the package proposed in this RFC will not match the implementations found in the above packages, those packages should provide a conceptual idea of what is desired. Do not simply copy-paste the code found in those packages without reasoning about expected behavior and API design.

Update source files

Once you've created package files, proceed to update all tests, documentation, and examples to reflect the API and expected behavior for the package. You should spend some time studying the tests in @stdlib/stats/incr/mvmr. We expect this package to have equivalent and fully comprehensive tests. The primary difference will be in the handling of NaN values.

To see an example of what is expected, study the tests in

• @stdlib/stats/incr/sum and @stdlib/stats/incr/nansum

Compare and contrast the tests in that pair of packages.

Run tests and other commands

For each of the following commands, please run them from the root stdlib repository directory (not the package folder!).

To run unit tests,

make test TESTS_FILTER=".*/stats/incr/nanmvmr/.*"

To run examples,

make examples EXAMPLES_FILTER=".*/stats/incr/nanmvmr/.*"

To run benchmarks,

make benchmark BENCHMARKS_FILTER=".*/stats/incr/nanmvmr/.*"

Create pull request

Provided all tests, examples, and benchmarks successfully execute and pass and that you've updated the package's documentation, you are now ready to open a pull request!

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Notes

• If you are interested in contributing a PR which addresses this RFC and still getting familiar with our project conventions, please do not submit LLM-generated code. Please consult our contributing guidelines and the associated development guide. Failure to respect project conventions will result in your PR being rejected without review. Thank you for understanding!

Checklist

• I have read and understood the Code of Conduct.
• Searched for existing issues and pull requests.
• The issue name begins with [RFC]:.

[stdlib-bot]

👋 Important: PLEASE READ 👋

This issue has been labeled as a good first issue and is available for anyone to work on.

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Before working on this issue and opening a pull request, please read the project's contributing guidelines. These guidelines and the associated development guide provide important information, including links to stdlib's Code of Conduct, license policy, and steps for setting up your local development environment.

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We place a high value on consistency throughout the stdlib codebase. We encourage you to closely examine other packages in stdlib and attempt to emulate the practices and conventions found therein.

• If you are attempting to contribute a new package, sometimes the best approach is to simply copy the contents of an existing package and then modify the minimum amount necessary to implement the feature (e.g., changing descriptions, parameter names, and implementation).
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In short, the more effort you put in to ensure that your contribution looks and feels like stdlib—including variables names, bracket spacing, line breaks, etc—the more likely that your contribution will be reviewed and ultimately accepted. We encourage you to closely study the codebase before beginning work on this issue.

✨ Thank you again for your interest in stdlib, and we look forward to reviewing your future contributions. ✨

[gkbishnoi07]

@kgryte working on it!