On Fri, Apr 30, 2004 at 04:57:00PM -0300, mo.domingues wrote:
> Dear colegues,
>
> I am interesting in direction field
> plots for a vectorial calculus class.
> I've read the 2003 menssages from
> Jaimes about he was starting new
> macros for it.
> Is there any progress on that ?
> I'll really appreciate if somebody
> could help to do it.
Hi Meg,
I've been too busy lately to complete that work.
You can enter the lisp interpreter in your maxima session and type:
(defun $plotdf() (show-open-plot "{plotdf}"))
back in maxima you can then use:
plotdf();
to launch the direction field interface.
You can also call Openmath's plotdf directly, without using Maxima, but
the way omplotdata works, it requires you to first create a file with the
commands to pass to it. For instance, in GNU/Linux I've created a file
/usr/local/bin/plotdf.openmath
with contents:
{plotdf}
and an executable script /usr/local/bin/plotdf :
#! /bin/sh
/usr/lib/maxima/5.9.0/omplotdata /usr/local/bin/plotdf.openmath
The unix command plotdf will then show you Openmath's direction fields
interface. The parser for the expressions of the differential equations
is very buggy though. Writing the same equations in two different ways
can lead to completely different results.
You might be interested in my portuguese lecture notes for "Dynamical
systems with Maxima": http://fisica.fe.up.pt/eic2107/apontamentos/
I'd also like to know more about your vector calculus class.
Cheers,
Jaime