New package for drawing direction fields with gnuplot

on Wednesday 17 of November 2010 12:46:39 Valery wrote:
> This is a wonderful extension!
> Thank you very much, Mark!
> Though, I'm personally not a fan of gnuplot.
> 
I meant fun :-), my accent penetrates in the writing :-)
> 
> on Tuesday 16 of November 2010 14:56:22 Mark wrote:
> > Hello all,
> > 
> > I have created a new package, drawdf, for drawing direction fields
> > using Maxima and gnuplot.  Although it lacks the interactive
> > convenience of plotdf, it is far more flexible and produces nicer
> > looking results.  It also has better integration with wxMaxima and
> > Imaxima, allowing inline plots via wxdrawdf.
> > 
> > For a brief demonstration of drawdf's capabilities, please see:
> >    http://www.netris.org/~mhw/maxima/drawdf-demo.html
> > 
I wonder if the things that shown in the demo would be possible to extend
for 3d field. For example,  these days i'm trying to visualize the fields 
which is closed in  the spherical shell. I do it with mayavi, though I have 
success in showing the field by arrows. The picture is bit messy the builtin 
flow function does not work for me and I have to implement the integration 
procedure myself. The complication is that field components are not given in 
analytical form they are results of simulation

all the best!
Valery

> > Note that drawdf is built upon the draw package, and passes very long
> > lists of graphic objects to draw2d.  This exposes a scalability
> > problem with draw2d, namely that it requires stack space proportional
> > to the number of graphic objects.  Fortunately, the fix is simple.
> > Just replace the recursive definition of draw-transform in draw.lisp
> > with the following iterative version:
> > 
> > (defun draw-transform (expr transform)
> > 
> >   (reduce #'append
> >   
> >           (mapcar #'(lambda (x) (draw-transform-one x transform))
> >           
> >                   expr)
> >           :
> >           :from-end t))
> > 
> > Drawdf is part of my recent work supporting the use of Maxima in two
> > classes on differential equations at Brown University, and more
> > importantly in an upcoming textbook by Vladimir Dobrushkin, due out
> > next year.  However, the textbook can only describe commands which are
> > included in the official Maxima release.
> > 
> > With that in mind, is there any chance drawdf (plus the above fix)
> > could be included in the next Maxima release? :)
> > 
> > Comments and suggestions are of course welcome.
> > 
> >      Best,
> >      
> >       Mark
> > 
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> > Maxima at math.utexas.edu
> > http://www.math.utexas.edu/mailman/listinfo/maxima
> 
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