www.pudn.com > voiceprocessingtoolbox.rar > fftRepeat01.m

% This example demos the effect of FFT for purely periodic signals 
[y, fs]=wavread('welcome.wav'); 
x=y(2047:2126);		% A full fundamental period 
 
runNum=5; 
for i=1:runNum 
	repeatedX = x*ones(1,i); 
	signal = repeatedX(:); 
%	signal=zeros(runNum*length(x), 1);		% Zero-padding version 
%	signal(1:length(repeatedX))=repeatedX(:);	% Zero-padding version 
	[mag, phase, freq, powerDb]=fftOneSide(signal, fs); 
	mag=mag/length(signal);	% Divided by vector length to normalize magnitude (due to the formula used by MATLAB) 
 
	subplot(runNum,2,2*i-1); 
	plot(signal, '.-'); grid on 
	title('x[n]'); set(gca, 'xlim', [-inf inf]); 
 
	subplot(runNum,2,2*i); 
	plot(freq, mag, '.-'); grid on; 
%	set(gca, 'yscale', 'log'); 
	title('DFS of x[n]'); axis tight; 
end