If I remember correctly, the "0 limitation there was because d. was
explicitly rank 0 --
https://www.jsoftware.com/help/dictionary/dddot.htm
Meanwhile, of course, D. dealt with verbs at rank --
https://www.jsoftware.com/help/dictionary/ddcapdot.htm -- but getting
that right would have been a bit more work, and I didn't have a good
set of tests in mind to verify that I was approaching things correctly
there.
I hope this helps,
--
Raul
On Fri, Feb 24, 2023 at 10:58 AM Jan-Pieter Jacobs
wrote:
>
> I was looking at Raul's pull request for math/calculus here:
> https://github.com/jsoftware/math_calculus/pull/5 . This would simplify a
> lot of derivatives, especially ones involving sines and cosines, which
> cause higher order derivatives to explode in the current version.
>
> I've been granted push rights on the repo, but I'm not 100% sure I
> understand the code proposed, and I'm also not sure how to use Github's
> code review tools (in fact, not being a programming professional, I never
> did a code review at all). How is this supposed to work? Are the Github
> tools used in general for collaboration on jsoftware's addons?
>
> I'm doubting about the lines 164-166 (
> https://github.com/rdm/math_calculus/blob/796ddac9de3863bf6746861624bb6aad8b70b9a2/calculus.ijs#L164),
> where it seems to me that in x atops y, when y happens to be -@verb, just
> discards x and -@, keeping only "verb". I think this should only happen if
> x is -, i.e. I think a check is missing.
>
> Secondly, for now, constants, zeros, ones and negative ones are considered
> only if they are rank 0 (see lines 173, 178-180, at
> https://github.com/rdm/math_calculus/blob/796ddac9de3863bf6746861624bb6aad8b70b9a2/calculus.ijs#L173).
> Would it hurt to also accept them at other ranks (e.g. 0: , 0"_), e.g.
> would it have unexpected effects on pderiv? deriv_jcalculus already accepts
> 0: and related primitives for deriv and intg (and could likely be extended
> to accept 0"_, 1"_, etc as well).
>
> Thanks for your observations.
> Jan-Pieter
>
> PS: if you're all too busy preparing the j9.4 release, no rush, it can wait.
> --
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