a=3+4*i %复数
real(a) %求复数的实部
imag(a) %求复数的虚部
abs(a) %求复数的模
angle(a) %求复数的相位
conj(a) %求复数的复共轭

%% Irradiance and phase resulting 
figure
subplot(2,2,1)
mesh(2.*xn./D2,2.*yn./D2,abs(Uvac).^2);
subplot(2,2,2)
mesh(2.*xn./D2,2.*yn./D2,abs(Uvac).^2);
view(90,90)
axis([-5 5 -5 5])
subplot(2,2,3)
mesh(2.*xn./D2,2.*yn./D2,angle(Uvac));
subplot(2,2,4)
mesh(2.*xn./D2,2.*yn./D2,angle(Uvac));
view(90,90)
axis([-5 5 -5 5])