New package for drawing direction fields with gnuplot

Hi,

Thx for new package.

I have tried it :

(%i1) load("/home/adam/Pulpit/drawdf.mac")$
(%i2) wxplot_size: [600,400];
(%o2) [600,400]
(%i3) wxdrawdf(2*cos(t)-1+y, [t,-5,10], [y,-4,9], [trajectory_at,0,0])$
Maxima encountered a Lisp error:
 Error in PROG [or a callee]: The variable $MAKE_F_RK_4 is unbound.
Automatically continuing.
To enable the Lisp debugger set *debugger-hook* to nil.
(%i4) build_info()$
Maxima version: 5.20.1
Maxima build date: 8:52 2/16/2010
Host type: x86_64-unknown-linux-gnu
Lisp implementation type: GNU Common Lisp (GCL)
Lisp implementation version: GCL 2.6.7



What is wrong ?

Adam


Dnia Tue, 16 Nov 2010 17:56:22 -0500, Mark H Weaver napisa?(a):

> 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
> 
> 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