@acer thanks (again)

@acer I misread your suggestion

@acer @tomleslie

(not sure why the figures didn't attach)

with(plots);

Op1 := Array(-10 .. 10, -10 .. 10, proc (i, j) options operator, arrow; j^2+i^2 end proc):
Op2 := Array(-25 .. -10, -25 .. -10, proc (i, j) options operator, arrow; i^(3)+j end proc):

surfdata(Op1,-10..10,-10..10); # Op1 an array of elements -10 <=i,j<=+10

surfdata(Op1,25..35..,25..35); # this just relabels the axes, Op1 not defined?

surfdata(Op2,-25..-10,-25..-10); # Op2 an array of elements -25<=i,j<=-10

surfdata({Op1,Op2},-25..10,-25..10); #this justs puts the plots on the same scaled axes?

@acer I would like to be able to plot the contours for a given level surface like

myfn := proc (x::numeric, y::numeric)

local output; output := 15.*x^2+y^2

end proc;
xst := -1.; xfn := 1.; yst := -1.; yfn := 1.; myk := 1.;

contourplot(myfn, xst .. xfn, yst .. yfn, contours = [myk]);