Assuming what I can now see is the latest version, line 174 still looks wrong:
if. coeffs=. -: '' do. '0&p.' return. should be if. coeffs -: '' do. '0&p.' return. ... but perhaps that’s already been done in another incarnation. Cheers, Mike Sent from my iPad > On 7 Feb 2021, at 15:18, chris burke <[email protected]> wrote: > > Thanks, the addon is updated now. > > On Sun, Feb 7, 2021 at 6:13 AM 'Jon Hough' via Programming > <[email protected]> wrote: >> >> Mike, thanks. I noticed I missed that out too. >> >> I have added fexp and merged. >> >> Thanks, >> Jon >> On Sunday, February 7, 2021, 09:19:56 PM GMT+9, 'Michael Day' via >> Programming <[email protected]> wrote: >> >> For interest, I had a look at the changes in the script. >> >> I tried both derivatives, and both failed in different ways: >> a) polynomials using p. : >> (1 2 3 & p. ) deriv 1 NB. result should be 2 6&p. >> 0&p. >> (0 & p. ) deriv 1 NB. ok! >> 0&p. >> >> b) f() ^ h() >> (*: ^ *:) deriv 1 >> |domain error: deriv_jcalculus_ >> | 13!:8(3) >> >> After some puzzlement, I traced the difficulties with each: >> a) line 170 >> if. coeffs=. -: '' do. '0&p.' return. >> should of course be >> if. coeffs -: '' do. '0&p.' return. >> >> b) I couldn't see what was wrong until I realised that fexp is undefined! >> So adding a definition along the lines of the other fops removes the >> error condition. >> >> fexp =: 4 : 0 >> '((',x,')^(',y,'))' >> ) >> >> I wouldn't dare try altering the online source code! >> >> Cheers, >> >> Mike >> >>> On 05/02/2021 04:34, 'Jon Hough' via Programming wrote: >>> I wrote a bug report and fix in the source chat a couple of weeks ago. >>> There was no response, so I guess I wrote in the wrong chat. >>> >>> The calculus addon script has one glaring issue, and one small issue with >>> an easy fix. >>> >>> The glaring issue is the inability to differentiate the constant zero >>> function >>> >>> 0&p. >>> >>> that gives an error. >>> >>> The fix is here: https://github.com/jsoftware/math_calculus/pull/2 >>> >>> I think this should be fixed asap, as it also causes an error on double >>> differentiation of a linear polynomial. >>> >>> 1 2&p. >>> >>> The other issue is differentiating a general f^g function, which currently >>> gives an error, but is easily doable. >>> >>> Thanks, >>> Jon >>> ---------------------------------------------------------------------- >>> For information about J forums see http://www.jsoftware.com/forums.htm >> >> >> -- >> This email has been checked for viruses by Avast antivirus software. >> https://www.avast.com/antivirus >> >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
