clear all;
close all;
dy=[-10:0.5:10];
dx=dy;

for i=1:length(dx)
    for j=1:length(dy)
        testAtan(j,i)=atan2(dy(j),dx(i));
        if dx(i)==0
            testAtan_bis(j,i)=atan2(dy(j),dx(i));
        else
            testAtan_bis(j,i)=atan(dy(j)/dx(i));
        end
    end
end
figure;
surf(dx,dy,testAtan)
title('atan(dy/dx)')

figure;
surf(dx,dy,testAtan_bis)
title('atan(dy/dx)')
% figure;
% Q=unwrap(unwrap(testAtan)')';
% surf(dx,dy,Q)
% title('atan(dy/dx)')