How to load a specific channel from EEG into MATLAB

Hi. I am just new to EEG and also MATLAB. Currently, I am having a 14 channels EEG data, however I need only signal from 2 specific channel for analysis. How can I load the only 2 channels into MATLAB using edfread? Then, I am able to convert the data into frequency domain with the following codes but it is converting all 14 channels. Therefore, what should I modify from the existing code to get only 2 channel of signal being converted?

[header,data] = edfread("data.edf");
S = data;
y=fft(S);
PS=abs(y);
N=length(S);
fs=128;
freq=(1:N)*fs/N;
plot(freq,PS)

Your help will be highly appreciated. Thanks

Answer 1

[dpb]

Often unless data files are simply humongous, it's just simpler to read it all in and then selectively keep what you're interested in...

nKeep=[3 11];        % arbitary selection; write some user input code to set the desired channel(s)
[header,S] = edfread("data.edf");
S = S(:,nKeep);      % keep only the desired channels..
...

Carry on from there as before...

[David Lee]

Thanks for your answer. Is it meaning that if I want to select only channel (e.g: channel 7), the code will be like below: ?

nKeep = 7;

[header,S] = edfread("data.edf");

S = S(:,nKeep);