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| Etude des impulsions
clear
load sm_coeur.dat;
Fe=360;Te=1/Fe;Ts=1/1.22;
m=sm_coeur;m=m-mean(m);
for k=1:length(m)
if m(k)<40
m(k)=0;
else
m(k)=m(k);
end
end
n=length(m);
plot((1:n)*Te,m)
grid
Nx=length(m);
FFT_size=length(m);
X=fft(m,Nx);
figure(2)
tf=fft(m,Nx);
w=Fe*(0:Nx-1)/Nx;
plot(w(1:fix(Nx/50)),abs(tf(1:fix(Nx/50))));
grid
xlabel('Fréquences en Hz')
title('Module de la fft')
Pxx = X.* conj(X) / Nx;
f = Fe*(0:Nx-1)/Nx;
figure(3)
plot(f(1:100),Pxx(1:100))
title('Spectre de puissance y')
xlabel('frequence (Hz)')
grid
[P,fd]=psd(m,Nx,Fe,w,0 );
figure(4)
plot (fd(1:100),P(1:100));
grid
title('DSP y')
xlabel('frequence (Hz)')
%Calcul des fréquences
se=m>200;
[i,j,v]=find(se==1);
fs=1./(diff(j)*Te);
freqs=fs(fs~=360)
disp(['Fréquences successsives en Hz = ' num2str(freqs)]) |
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