% Sample file to produce an energy surface (kx,ky).
% We use a square lattice tight binding energy here.

k = linspace(-pi,pi,200);

[kx, ky] = meshgrid(k,k);
E = - cos(kx) - cos(ky);

surf(kx,ky,E)
xlabel('kx')
ylabel('ky')
zlabel('E')
