f=@(X,Y) 2+X-Y+2*X.^2+2*X.*Y+Y.^2;
plot3dfunc(f,-2,0,0,3)
function plot3dfunc(f,Xmin,Xmax,Ymin,Ymax)
x=linspace(Xmin,Xmax,50);
y=linspace(Ymin,Ymax,50);
[X,Y] = meshgrid(x,y);
Z = f(X,Y);
subplot(1,2,1);
cs=contour(X,Y,Z);clabel(cs);
xlabel('x_1');ylabel('x_2');
title('(a) Contour plot');grid;
subplot(1,2,2);
cs=surf(X,Y,Z);
zmin=floor(min(Z));
zmax=ceil(max(Z));
xlabel('x_1');ylabel('x_2');zlabel('f(x_1,x_2)');
title('(b) Mesh plot');
end