function hf2_display(C_col,phi)

N_basis = length(phi);
[x y] = meshgrid(-2:0.1:5,-2:0.05:2);

psi = zeros(length(y(:,1)),length(x(1,:)));
for A = 1:N_basis
    psi = psi + C_col(A) * phi(A).coeff * ...
            exp(- phi(A).exp * ((x-phi(A).R(1)).^2 + (y-phi(A).R(2)).^2));
end
surf(x,y,psi.^2);
ylim([-2.5 2.5]);