fig6_10.m

数字信号处理Matlab演示文件,其中各个文件加放置了不同的matlab子文件

echo on
%	Figure 6.10
% 	order 20 FIR filter with (a) rectangular window (continous line)
%				 (b) Hamming window     (dotted line)
echo off
%
% 	Ms Oh; Revised BM July 1998

clear
clf
colordef(1,'white')


n = 20;				% filter order
wn = 0.1;			% normalised cut of frequency
wn = 2*wn;			% scale for MATLAB
 
b = fir1(n,wn,boxcar(n+1));
[h,w] = freqz(b,1,256);
mag = 20*log10(abs(h));
f = w/2/pi;

b1 = fir1(n,wn,hamming(n+1));
[h1,w] = freqz(b1,1,256);
mag1 = 20*log10(abs(h1));

plot(f,mag,f,mag1,'-.')
xlabel('normalised frequency')
ylabel('gain (dB)')
axis('square')

%gtext('rectangular');
%gtext('window');
%gtext('Hamming');
%gtext('window');

%print a:fig6-9.eps -deps