eegfft.m

This Program is an M-file to implement a low-pass filter and notch filter (50Hz) on EEG channels.

clc;close all
% load EEG1
load Sajad__Eyes_closed
V=[];
for i=1:19
    channel1 = Sajad__Eyes_closed(:,i);
    wo = 50/(256/2);  bw = wo/50;
    [b,a] = iirnotch(wo,bw);
    h=filter(b,a,channel1);
    V=[V,h];
end;

save('V.mat','V');
% ch=timeseries(channel1(:,1),1:24832);
% T=[.09 .2];
% chf=idealfilter(ch,T,'notch');
% xk=chf.data;
% xk2=zeros(1,24832);
% xk2(1,:)=xk(1,1,:);

% Fs = 1;                    % Sampling frequency
% T = 1/Fs;                     % Sample time
% L = 48896;                     % Length of signal
% t = (0:L-1)*T;                % Time vector
% y = h;
% y2 = channel1';
% NFFT = 2^nextpow2(L);           % Next power of 2 from length of y
% Y = fft(y,NFFT)/L;
% Y2 = fft(y2,NFFT)/L;
% f = Fs/2*linspace(0,1,NFFT/2);
% figure
% plot(f(4:end),2*abs(Y2(4:NFFT/2)),'.r') ; hold on; plot(f(4:end),2*abs(Y(4:NFFT/2)));
% xlabel('Frequency (Hz)')
% ylabel('|Y(f)|')