Jmv - if you just want to perform the FFT on each file, then wouldn't your code look something more like
%INITIALISATION
% % % % % % % % % % % % % % % % % % % % % % % % % % % %
Ts = 0.00005; % Sampling Interval (seconds)
Fs = 1/Ts; % Sampling Frequency (Hz)
Fn = Fs/2;
path = genpath('C:\Users\Power User\Desktop\');
x31 = csvread('test data1.csv',2); %read data
x32 = csvread('test data1.csv', 2);
x33 = csvread('test data1.csv', 2);
Details = (strsplit(path,'\')); %extract details for plot titles from path name
Details = char(Details(2));
Signal = {x31;x32;x33};
for k = 1:length(Signal) % <------- iterate over each file
%PERFROM FFT
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
N = length(Signal{k}(:,2));
meanSignal = mean(Signal{k}(:,2)); % kSignal(:,2) Mean
FTSignal = fft(Signal{k}(:,2) - meanSignal)/N; % Normalised Fourier Transform Of Baseline-Corrected {Signalk.
% etc.
end
The above code iterates over each dataset stored in Signal. On each iteration, we consider the dataset at Signal{k}.
