[RFC]: add C implementation for math/base/special/gammaln

[performant23]

Description

This RFC proposes adding native C implementation for @stdlib/math/base/special/gammaln

double stdlib_base_gammaln ( const double x );

Related Issues

Issue Tracker: #649

Questions

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Other

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Checklist

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

[performant23]

Hello, I am working on this issue!

[performant23]

Hello, I just had a doubt regarding scripts/evalpoly.js. For reference, I checked out this PR and the changes into this file.
If I understand correctly, the goal is to extend the functionality to compile polynomial functions in C and insert them into a source file. We're inserting the function string between // BEGIN and // END, creating copts - options object for compileC, read the file and we write the compiled function into the file (using insert).

So basically we're evaluating these polynomials and inserting them into the source files (after compiling). I just wanted to know more on its role and usage on the C implementation and on the library in general since gammaln has a similar script for polynomials.

@kgryte, @Planeshifter

[kgryte]

@performant23 Your understanding is correct. You need to insert some markup into the C source file so that the script knows where to insert the equations. For generating the polynomial equations, rather than handwrite, we use code generation.

[performant23]

Hi @kgryte, I request you to temporarily block this issue. I've just discovered an overlooked dependency in the C implementation of special/sinpi, which also relies on special/sin and special/cos. Apologies for not noticing this sooner. Realized this since I encountered an error during compilation and execution of the package.

[kgryte]

@performant23 Thanks for the update. Will update the status.