plotdf



Hi Jaime ,

Thank you very much  for answer.

>> Can I plot equipotential lines (contour lines) of this filed using
>> plotdf ?
> No you can't. Plotdf works passing a function to openmath once that
> function is passed to the plotdf tcl/tk script, it is that script and no
.....
> 
> For instance, you can use a function that you would write in a C program
> such as: x^2*sin(x), but you cannot use a function that you previously
> defined in Maxima, such as GiveFLogPhi(z0,c,e_r,i_max).

I have the same function in c :

double jlogphi(double zx0, double zy0, double cx, double cy)
/* this function is based on function by W Jung */
{
  int j;
  double
  zx=zx0,
  zy=zy0,
  s = 0.5,
  zx2=zx*zx,
  zy2=zy*zy,
  t;
  for (j = 1; j < 400; j++)
  { s *= 0.5;
   zy = 2 * zx * zy + cy;
   zx = zx2 - zy2 + cx;
   zx2 = zx*zx;
   zy2 = zy*zy;
   t = fabs(zx2 + zy2); // abs(z)
   if ( t > 1e24) break;
  }
return s*log2(t);  // log(zn)* 2^(-n)
}//jlogphi

Can it be used for plotdf ?
> 
> To make it work, plotdf should undergo a major change: maxima would
> invoke the plotdf tcl/tk script which should communicate with the
> current maxima session to make all of its calculations.

Drawing field lines and contour lines is very important to me.
If I could help I will do my best . (:-)

Regards

Adam