> #sfb sep 23, 2002; modified 6 feb 03
> with(plots);with(plottools);
> e:=exp(1);fun:= 3*(1-x)^2*e^(-x^2-(y+1)^2)
>     - 10*(x/5-x^3-y^5)*e^(-x^2-y^2) -(1/3)*e^(-(x+1)^2-y^2);xrange:=-3..3;
> fun:=(x^2-1)*(y^2-1);xrange:=-1.5..1.5;
> fun:=x*y*(x+y-3);xrange:=-0.5..3.5;
> fun:=sin(x)*sin(y);xrange:=0..2*Pi;
> fstring:=convert(fun,string);ftitle:="The good doctor's "||fstring;
> a:=contourplot(fun,x=xrange,y=xrange,contours=15):
> b:=gradplot(fun,x=xrange,y=xrange,arrows=thick):
> display(a,b,scaling=constrained,title=ftitle);
> t:=transform(unapply([x,y,fun],x,y)):
> display(t(a),t(b),title=ftitle);
>