New package for drawing direction fields with gnuplot

Dnia Thu, 18 Nov 2010 23:50:05 -0700, Robert Dodier napisa?(a):

> On 11/18/10, Adam Majewski <adammaj1 at o2.pl> wrote:
> 
>>  Error in PROG [or a callee]: The variable $MAKE_F_RK_4 is unbound.
> 
>> Maxima version: 5.20.1
> 
> I suspect this is a bug in the Maxima -> Lisp translation code, which
> was fixed a while ago. Maybe you can try it again with a newer version
> of Maxima. Or, if not, just comment out the call to compile make_f_rk_4.
> 
> best,
> 
> Robert Dodier

I have upgraded Maxima and now it works.
Thx

I allways wanted something like this

f(x,y):=sqrt(x*x+y*y); 
wxdrawdf(f(x,y), [x,-2,2], [y,-2,2], field_color=gray,
key="soln 1", color=black, soln_at(0,0),
key="soln 2", color=red, soln_at(0,1),
key="isocline", color=green, line_width=2, nticks=100)$

soln_at draw field lines, so how can I draw equipotential lines ?

Regards

Adam