Having trouble with direction fields



On Mon, 2010-11-15 at 16:49 +1100, Michael Carey wrote:
> load("plotdf");
> 
> plotdf(.5*(1-y/4)*y,[x,-2,6],[y,-2,6])$
> 
> I do not get a graph, I am using wxmaxia, and graphs are working fine.
> 
> Am I doing something wrong? 

Have you already installed xmaxima? without it plotdf will not work.
Best regards,
Jaime Villate