% ECE/CS 533 lecture 7 example 1. (l7e1.m)
% spectrum of a 2D function
% f(x,y) = 1 between (0,0)  (X,Y)
% |F(u,v)| and image of |F(u,v)| are plotted
% 
% (c) copyright 1997  by Yu Hen Hu
% created: 9/20/97

f=ones(5,5);
G=fft2(f,63,63); G1=[G(33:63,33:63) G(33:63,1:32);
   G(1:32,33:63) G(1:32,1:32)];
figure(1),surf(abs(G1));colormap('hsv')