Combining 3D and contour plots (2)

t=%pi*(-10:10)/10;
deff('[z]=surf(x,y)','z=sin(x)*cos(y)');
rect=[-%pi,%pi,-%pi,%pi,-1,1];
z=feval(t,t,surf);
plot3d(t,t,z,35,45,'X@Y@Z',[-20,1,3],rect);
xset('alufunction',0);
contour(t,t,z,10,35,45,'X@Y@Z',[0,1,0],rect);
xtitle('plot3d and contour',' ',' ');