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 <janpieter.jac...@gmail.com> 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. > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
