Derivatives of the incomplete gamma functions with respect to parameter `a` are missing
Nobody has claimed this yet.
Assessment
- Difficulty
- 5/5
- Estimated time
- Over a week
- Newbie friendliness
- 25/100
Research direction
Start by reviewing the referenced SpecialFunctions.jl pull request #305 and the Wolfram Functions derivative formulas for the incomplete gamma functions. Compare the existing ChainRules definitions for gamma(a, x), loggamma(a, x), and gamma_inc with the analogous Bessel-function handling. Done means derivatives with respect to a are implemented and the missing-derivative error message links to this issue.
Written by the indexing model from the issue text.
Description
Copied from https://github.com/JuliaMath/SpecialFunctions.jl/pull/305:
I added ChainRules definitions for gamma(a, x), loggamma(a, x), and gamma_inc according to https://functions.wolfram.com/GammaBetaErf/GammaRegularized/introductions/Gammas/ShowAll.html . Similar to the Bessel functions, derivatives with respect to the first argument a are not implemented since they are given in terms of a (regularized) hypergeometric function.
This issue is a reminder that these derivatives are missing. Moreover, the issue can be linked in the error message displayed to users when they try to access and perform computations with these missing derivatives.
- Dominant language
- Julia
- Stars
- 384
- Forks
- 115
- Avg merge
- 2d 9h
- Merged PRs (30d)
- 2
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