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| %%%pas en fréquence %%%%
pas=1/(Zu.npts*Zu.delta);
P=Zu.trace;
%%% Selection des fenêtres signal
Psnew=P(1049:5759);
%%% Selection des fenêtres bruit
Pbnew=P(1:1040);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%% En fréquence %%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%% vérifier longueur point%%%
n=1;
while 2^n<length(Psnew);
n=n+1;
end;
corr=2^n;
plus=corr-length(Psnew);
ajout=zeros(plus,1);
newPs=vertcat(Psnew,ajout);
N=length(newPs);
plusa=N-length(Pbnew);
ajouta=zeros(plusa,1);
newPb=vertcat(Pbnew,ajouta);
Na=length(newPb);
%%%% Transformée de fourier
PSf=fft(newPs);
PBf=fft(newPb);
%%%% Selection d'une partie
Sf=PSf(1:length(PSf)/2-1);
Bf=PBf(1:length(PBf)/2-1);
dureeS=length(Sf)*Zu.delta;
dureeB=length(Bf)*Zu.delta;
%%%% Module
dt=Zu.delta;
l=length(Sf);
if nargin<2
dk=1/l;
else
dk=1/dt/l;
end
t=0:dk:(l-1)*dk;
TFS=horzcat(reshape(t,[length(t),1]),abs(Sf));
dt=Zu.delta;
l=length(Bf);
if nargin<2
dk=1/l;
else
dk=1/dt/l;
end
t=0:dk:(l-1)*dk;
TFB=horzcat(reshape(t,[length(t),1]),abs(Bf));
%%% Normalization pour même longueur
Psnorma=TFS./sqrt(dureeS);
Pbnorma=TFB./sqrt(dureeB);
%%%Lissage
Pslisse=smooth(Psnorma);
Pblisse=smooth(Pbnorma);
%%%% Rapport signal sur bruit
SB=Pslisse./Pblisse;
plot(pas*(0:length(SB)-1),SB);
hold on; plot([0 length(SB)*pas], [3 3],'g'); |
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