New package for drawing direction fields with gnuplot

> One suggestion: it would be helpful if you could also accept lists
> within lists, to arbitrary depth.  I now do this in drawdf, and it has
> proved convenient in some cases.

Done in repository. Something like this should now work:

colors:[red, blue, green, brown, "#f740d4"] $

gr: makelist(
    [  color = colors[k],
       [key = concat("Slope = ", 3*k)] ,
       explicit(3*k*x,x,-1,1)],
    k, 1, 5) ;

draw2d(gr);

--
Mario