%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Figure 4.14
% Contour plot of uniformly weighted rectangular array
% Xiaomin Lu 11/2/98	
% Updated by K. Bell 9/29/00, Lillian Xiaolan Xu 02/12/2001, K. Bell 9/30/01
% Updated by K. Bell 1/17/08
% Functions called: sinc
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


close all
clear all
N = 10;
M = 10;


[ux,uy] = meshgrid(-1:1/50:1);
psix = pi*ux;
psiy = pi*uy;

Beam = sinc(1/pi*N*psix/2)./sinc(1/pi*psix/2);
Beam = Beam.*sinc(1/pi*M*psiy/2)./sinc(1/pi*psiy/2);
Beam = abs(Beam)/max(max(abs(Beam)));
Beam = 20*log10(Beam);
for i = 1:size(Beam,1)
   for j = 1:size(Beam,2)
      if (Beam(i,j)< -60)
         Beam(i,j) = -60;
      end
   end
end

x = -1:1/50:1;

cs = contour(x,x,Beam);
grid off
xlabel('\it u_x','Fontsize',14)
ylabel('\it u_y','Fontsize',14)
axis square