MATLAB and C Programs - Digital Signal Processing: A Practitioner's Approach - page 132

%title ('Fig 1.8')
%print -depsc f1_8;
A.1.4 Program f 11_901
%Digital Signal Processing:A Practitioner's Approach
%Dr.Kaluri Venkata Ranga Rao, [e-mail]
%Generates figure 1.5 and 1.6
clear;close;
fs=10e3;T=1/fs;
t = 1:1000;
fc = 0.3;
Q = 100;f1 = fc - (fc/Q);f2 = fc + (fc/Q);
uk = randn(size(t));
wn = [f1 f2];
[b,a] = butter(2,wn);
[h,w] = freqz(b,a,360);
m = abs(h);F =w/(2*pi);
xk = filter(b,a,uk);
t=t*T;
subplot(211);plot(t,xk);grid;
% title(' Fig 1.9 ');
print -depsc f1_9; pause;
[sxk,f] = spk(xk,1);
subplot(211);plot(f*fs,sxk);grid;
% title(' Fig 1.10 ');
xlabel(' Frequency in Hz. ');
print -depsc f11_0; pause
subplot(211);plot(F*fs,m);grid;
% title(' Fig 1.11 ');
xlabel(' Frequency in Hz. ');
print -depsc f11_1
A.1.5 Program f 11_23458
%Digital Signal Processing:A Practitioner's Approach
%Dr.Kaluri Venkata Ranga Rao, [e-mail]
%Generates figure 1.7,1.8,1.9
%This program needs spk.m, expand.m
clear;close;
fs=10e3;T=1/fs;
f=0.001;