how can i pick out the peaks which I have already detected.

I need to pick out 3 sec signals around the peaks, not find it. (only the information signal you know).

make the whole ECG signals into two parts, 1st peaks 2nd noises

code:

clear all 

clc 
load('Sig100ch1.mat')
DeN_Sig = sgolayfilt(ans,15,17);
DeN_Sig = DeN_Sig - mean (DeN_Sig );
figure(1)
plot(1:length(DeN_Sig),(DeN_Sig))

figure(2)
plot(DeN_Sig.*abs(DeN_Sig)/max(abs(DeN_Sig)))
[pks,locs] = findpeaks(DeN_Sig,'MinPeakHeight',0.5,... 'MinPeakDistance',200);
figure(3)
plot(1:length(DeN_Sig),DeN_Sig);  hold on
plot(locs,pks,'k^','markerfacecolor','r'),

Answer 1

[dpb]

delt=1.5/dt;                 % the delta either side; dt is sampling time
locplus=round(locs+delt);    % the bands about the peaks
locminus=round(locs-delt);

[hansong]

this is a good one, but how can I get signals from every locsminus to locplus?

thank you appreciate it

[dpb]

You've got the arrays of lower/upper positions; use them in arrayfun or a loop to access the values at those locations.