[theta r]=meshgrid(linspace(0,2*pi,100),linspace(0,1,20));
[x y]=pol2cart(theta,r);
z=x.*y;
mesh(x,y,z);
[r,t]=meshgrid(0:0.1:1,0:0.02:2*pi);
x=r.*cos(t);
y=r.*sin(t);
mesh(x,y,z)
