Am Donnerstag, den 29.09.2011, 08:23 -0500 schrieb Barton Willis:
> -----maxima-bounces at math.utexas.edu wrote: -----
> >For integrals, you can return a value of nil and this is converted to a
> >noun form. The code for this is in function integrallookups in
> >sin.lisp. Examples of usage for the first arg of Bessel functions are in
> >bessel.lisp.
>
> >I think the same happens for derivatives.
>
> Thanks--this works. I knew this trick for integrals, but I didn't know it for
> derivatives. With this change:
>
> (%i20) diff(generalized_lambert_w(k,x),k);
> (%o20) 'diff(generalized_lambert_w(k,x),k,1)
>
> (%i21) integrate(generalized_lambert_w(k,x),k);
> (%o21) integrate(generalized_lambert_w(k,x),k)
>
> And all is well.
>
> Again, thanks for the advice.
The possibility to put NIL on the property list to get the noun form for
a derivative is present since revision 12.07.2009 of comm.lisp. I have
added the code, because of the wrong derivatives for the psi and li
functions, which had noun forms on the property list. The noun form must
be generated within the algorithm of the function sdiff.
Dieter Kaiser