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
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