Just noticed in MATLAB google groups, in this thread. There is a function preventing us to write nested loops i.e **ndgrid**.

Here the original code :

for habs=0:.25:1

for pabs=0:.2:1

for beta=0:pi/2:2*pi

for alpha=0:pi/5:2*pi

H=habs*(cos(beta)+i*sin(beta));

p=pabs*(cos(alpha)+i*sin(alpha));

W=abs(H)^2*abs(p)*(2*exp(i*(alpha-beta))+ exp(-i*(alpha- beta)))*exp(i*beta);

plot(real(W+H),imag(W+H),’o’,’MarkerSize’,4)

hold on

end

end

end

end

With ndgrid function, the code becomes :

[habs,pabs,beta,alpha]=ndgrid(0:.25:1,0:.2:1, 0:pi/2:2*pi,0:pi/5:2*pi);

H=habs.*(cos(beta)+i*sin(beta));

p=pabs.*(cos(alpha)+i*sin(alpha));

W=abs(H).^2.*abs(p).*(2*exp(i*(alpha-beta))+ exp(-i*(alpha-beta))).*exp(i*beta);

W=W(:);

H=H(:);

plot(real(W+H),imag(W+H),’o’,’MarkerSize’,4)

Further, you may check the run time. Which one faster ?

### Like this:

Like Loading...

*Related*

Filed under: PhD Study

Ka, bulan November gw mau ke Norway.