%%% ECE 410:  11/3/05
%%%
%%% Script file to plot magnitude/phase of LPF designed using window
%%% method (rectangular window and Hamming window)

pltdefaults
wc=pi/4;
M=50;

b=fir1(M,wc/pi,ones(M+1,1),'noscale');
bhamm=fir1(M,wc/pi,'noscale');
[H,w]=freqz(b,1,2048,'whole');
[Hhamm,w]=freqz(bhamm,1,2048,'whole');

subplot(211)
plot(w/pi,abs(H),'b',w/pi,abs(Hhamm),'r--');
axis([0 2 0 1.2])
xlabel('Frequency normalized by \pi:  \omega/\pi')
ylabel('|H(e^{j\omega})|')
legend('Boxcar','Hamming',4)
tstr=sprintf('Magnitude response of %i-point LPF',M+1);
title(tstr)

subplot(212)
plot(w/pi,angle(H),'b',w/pi,angle(Hhamm),'r--');
legend('Boxcar','Hamming',4)
xlabel('Frequency normalized by \pi:  \omega/\pi')
ylabel('\angle H(e^{j\omega})')
tstr=sprintf('Phase response of %i-point LPF',M+1);
title(tstr)