Extension of the function $laplace to call $specint

Hello Robert,

thank you for your feedback.

There is still a problem with desolve. I had a second look at the code. The
early code of desolve uses Maxima variables which are initialized with symbols.

Before revision 1.9 of desoln.lisp

variable  value
-----------------
$teqns    '$teqns
$tvars    '$tvars
$ovar     '$ovar
$lavar    '$lvar
$flag     '$flag
$dispflag '$dispflag

This was changed in revision 1.9 to:

variable  value
-----------------
teqns     nil
tvars     nil
ovar      nil
lavar     nil
flag      nil
$dispflag nil

The problem is that at least the value of the variable LAVAR which contains the
parameter of the Laplace transformation is passed to $laplace. Therefore I have
changed the value of LAVAR to a gensym. But the second problem is, that when
$laplace fails we get a noun form which now contains the gensym (in the last
vesion we get the value false).

Thus, I think it is better not to use a gensym, but to use the original symbol
'$lvar as the value for the variable LAVAR.

Dieter Kaiser


-----Urspr?ngliche Nachricht-----
Von: robert.dodier at gmail.com [mailto:robert.dodier at gmail.com] 
Gesendet: Donnerstag, 5. M?rz 2009 17:59
An: Dieter Kaiser
Cc: Maxima
Betreff: Re: [Maxima] Extension of the function $laplace to call $specint

On Wed, Mar 4, 2009 at 12:56 PM, Dieter Kaiser <drdieterkaiser at web.de> wrote:

> I have checked in an extension to $laplace to call $specint when $laplace
fails
> to find the laplace transform.

Thanks a lot. I think this is very helpful. The Laplace transform is
a topic of substantial practical importance.

best

Robert Dodier