MATLAB and C Programs - Digital Signal Processing: A Practitioner's Approach - page 157

subplot(222)
plot(t,e,'.-');grid
pause;
%print -depsc f4_5
N=nx+ny-1;
m=N-ny;
pad=ones([1 m])*0;
y(ny+1:N)=pad;
m=N-nx;
pad=ones([1 m])*0;
x(nx+1:N)=pad;
zhat=real(ifft(fft(x).*fft(y)));
t1=1:length(zhat);
subplot(211)
plot(t,z,'.-',t1,zhat,'o');grid;nn=length(zhat)
e=z; e(1: nn)=e(1:nn)-zhat;
%subplot(222)
%plot(t,e,'.-');grid
%pause
%print -depsc f4_6
A.4.3 Program f 4_62_0
%Digital Signal Processing:A Practitioner's Approach
%Dr.Kaluri Venkata Ranga Rao, [e-mail]
%Generates figure 4.18
clear
clg
subplot(111)
f=0.01;
a=[1 -0.89944 0.404496];
b=[0.126 0.252 0.126];
t=1:2^11;
zi=[0 0];
%rand('normal');
Fmax=50;
F=linspace(0.05,0.37,Fmax);
Kmax=length(F);
for k=1:Kmax;
f=F(k);
x=cos(2*pi*f*t);
[y,zf]=filter(b,a,x,zi);
zi=zf;