On Wed, 2008-09-17 at 16:44 -0400, Sam Steingold wrote:
> runge-kutta sounds good but it has been running on my amd64 ws for 20+
> minutes
> now... (maxima/sbcl):
>
> rk(dy/dx=cos(x*y),y,0,[x,0,5,0.1]);
You must be using an old version of the "dynamics" package. In more
recent versions, you should get the following error message, instead of
having to wait for ages:
Inconsistent set of equations and variables
#0: rk(odes=dy/dx =
cos(x*y),state=y,initial=0,domain=[x,0,5,0.1])(dynamics.mac line 391)
I advice you to update dynamics, since the newest version is much faster
and bug-free. You should be able to update it, without having to upgrade
the whole of Maxima, by simply replacing the files by those found in:
http://maxima.cvs.sourceforge.net/maxima/maxima/share/dynamics/
rk will also allow you to solve higher-order equations and systems of
equations. Please read the manual and tell me any suggestions for
improvements:
http://maxima.sourceforge.net/docs/manual/en/maxima_49.html
Regards,
Jaime Villate
(villate at gnu.org)