How is it typically decided whether some array function goes in numpy or scipy?
On Tue, Jun 9, 2026, at 11:08 AM, Lucas Colley via NumPy-Discussion wrote: > There was a proposal to add these to `scipy.special`: > https://discuss.scientific-python.org/t/rfc-add-sinpi-cospi-tanpi-and-cotpi-functions-to-special/1193. > There are existing implementations at > https://github.com/scipy/xsf/blob/main/include/xsf/trig.h , with `sinpi` and > `cospi` exposed to SciPy (privately) at > https://github.com/scipy/scipy/blob/main/scipy/special/xsf_wrappers.h#L394-L396. > > We should probably decide whether these best belong in `numpy` or > `scipy.special`, and only expose them in one of the two. > > Cheers, > Lucas > >> On 9 Jun 2026, at 16:23, Jerome Kieffer <[email protected]> wrote: >> >> I like the idea ! >> >> On Mon, 08 Jun 2026 08:59:24 -0500 >> "Jeff Epler" <[email protected]> wrote: >> >>> In a recently merged PR (https://github.com/python/cpython/pull/150555), >>> CPython has added a family of "*pi" functions to the math module, which >>> take half-turn arguments instead of radians. One reason these functions are >>> advantageous is that it's easy to provide the property that `sinpi(n/2)` is >>> exact for all integers n, while `sin(pi*n)` is never exactly equal to the >>> mathematical ideal except for n=0. >>> >>> These functions are recommended by IEEE754-2019 and standardized in C23 >>> Annex G. (note: I'm reading C23 draft revised 2023-01-24, not the final >>> standard document; and I do not have IEEE754-2019). >>> >>> C23 and CPython only added the real-valued versions of these functions, but >>> C23 "future library directions" notes that identifiers like `csinpi` are >>> "potentially reserved identifiers." >>> >>> Since CPython only requires C11, CPython includes implementations of these >>> functions for when the underling platform library does not provide it. >>> These implementations work by performing special case handling & range >>> reduction, followed by a call to the standard trig function with a scaled >>> argument (in the case of forward functions) or scaling of the result (in >>> the case of inverse/arc functions). >>> >>> I am interested in doing the numpy implementation, however I have never >>> done core numpy work before. If there is interest from the project, I would >>> like to initially offer a PR containing a single function such as `sinpi` >>> and then complete the others following numpy core developer feedback. >>> >>> Thanks, >>> Jeff >>> PS I notice via the archives that there are occasional "New Contributors' >>> Hour" meetings. Is the next one scheduled yet? >> >> >> >> >> -- >> Jérôme Kieffer >> tel +33 476 882 445 >> _______________________________________________ >> NumPy-Discussion mailing list -- [email protected] >> To unsubscribe send an email to [email protected] >> https://mail.python.org/mailman3//lists/numpy-discussion.python.org >> Member address: [email protected] > _______________________________________________ > NumPy-Discussion mailing list -- [email protected] > To unsubscribe send an email to [email protected] > https://mail.python.org/mailman3//lists/numpy-discussion.python.org > Member address: [email protected] >
_______________________________________________ NumPy-Discussion mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/numpy-discussion.python.org Member address: [email protected]
