Hello, I have EEG data from 42 participants (stored as .mat files in "from_path" directory). Each data file contains about 25,000 - 30,000 time stamps and 16 channels. I want to split the data into 3 intervals: from 1 to n1, from n1 to n2, and from 2 to the end (n1 and n2 are columns) and then calculate the average powers of the delta, theta, alpha, beta and gamma band. Then I want to store the output in a 16x5 table and save it.
Below is the my code, which calculates the average powers for the whole EEG file. How can I adjust in such a way that it calculates the average power for each segment?
Thank you in advance!
files = dir(strcat(from_path,'\*.mat'))
for i = 1:length(files)
filename = files(i).name;
data = load(filename).eeg;
srate = 250;
nChans = 16;
n1 = ..; % i have another function to extract the desired column
n2 = ..;
seg1 = data(:,1:n1);
seg2 = data(:,n1:n1+n2);
seg3 = data(:,n1+n2:end);
powers = zeros(1, 5);
for chan = 1:nChans
[spectra, freqs] = spectopo(data(chan,:,:), 0, srate,'windowsize',srate,'plot','off');
deltaIdx = find(freqs>0.5 & freqs<4);
thetaIdx = find(freqs>4 & freqs<8);
alphaIdx = find(freqs>8 & freqs<13);
betaIdx = find(freqs>13 & freqs<30);
gammaIdx = find(freqs>30 & freqs<45);
deltaPower = mean(10.^(spectra(deltaIdx)/10));
thetaPower = mean(10.^(spectra(thetaIdx)/10));
alphaPower = mean(10.^(spectra(alphaIdx)/10));
betaPower = mean(10.^(spectra(betaIdx)/10));
gammaPower = mean(10.^(spectra(gammaIdx)/10));
pow = [deltaPower, thetaPower, alphaPower, betaPower, gammaPower];
powers(end+1,:) = pow;
end;
powers(1,:) = []
ps = table(powers);
proc_filename = strcat(filename,".csv");
writetable(ps,proc_filename);
end;
