figure(1)u=-0.1:0.005:0.1;v=-0.1:0.005:0.1;[x,y]=meshgrid(u,v);z=sin(x-y)./abs(x)+abs(y);surf(x,y,z);hold on% contourf(x,y,z)% ezplot(‘x+y=3‘)% set(gca,‘DataAspectRatio‘,[1 1 60])%axis equal