For loop of an FFT script
2 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
Hussein Kokash
am 1 Nov. 2022
Bearbeitet: CHIRANJIT DAS
am 1 Nov. 2022
Hello,
I have a script that works for a single file using dlmread, the output seems to work fine. I need to put it inside a loop but I am getting some errors.
Here is the scipt for a single file:
z = data(:,1);
y = data(:,2);
T=data(:,3);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% % fft method
[fhz,fft_spectrum] = do_fft(z(:),y(:));
[amplitude1, idx] = max(fft_spectrum);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
L = length(z);
fs = 1/mean(diff(z)); % Sampling Frequency
fn = fs/2; % Nyquist Frequency
yc = y - mean(y); % Sampling Interval
FTv = fft(yc)/L; % Fourier Transform
Fv = linspace(0, 1, fix(L/2)+1)*fn; % Frequency Vector
Iv = 1:length(Fv); % Index Vector
[max_FTv, maxidx] = max(FTv(Iv));
Fv_at_max_FTv = Fv(maxidx);
wavelength1=1/Fv_at_max_FTv;
Any help would be appreciated, thanks!
0 Kommentare
Akzeptierte Antwort
CHIRANJIT DAS
am 1 Nov. 2022
Bearbeitet: CHIRANJIT DAS
am 1 Nov. 2022
@Hussein Kokash Not sure whether your files are located in a single folder or not. If it is in single folder then you can make use of below code..
loc='/Volumes/Backup Plus/path/'; % put path of your data files
cd(loc)
fnames=dir(fullfile('*.txt')); % Put the extension of your files
output=[];
for i=1:numel(fnames)
filename=fnames(i).name;
data = dlmread(filename) % I would suggest you to use readmatrix instead of dlmread.
z = data(:,1);
y = data(:,2);
T=data(:,3);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% % fft method
[fhz,fft_spectrum] = do_fft(z(:),y(:));
[amplitude1, idx] = max(fft_spectrum);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
L = length(z);
fs = 1/mean(diff(z)); % Sampling Frequency
fn = fs/2; % Nyquist Frequency
yc = y - mean(y); % Sampling Interval
FTv = fft(yc)/L; % Fourier Transform
Fv = linspace(0, 1, fix(L/2)+1)*fn; % Frequency Vector
Iv = 1:length(Fv); % Index Vector
[max_FTv, maxidx] = max(FTv(Iv));
Fv_at_max_FTv = Fv(maxidx);
wavelength1=1/Fv_at_max_FTv;
output=[output;wavelength1];
end
If you want to save wavelength, then you can find it in output. You can save your desire outputs this way.
0 Kommentare
Weitere Antworten (0)
Siehe auch
Kategorien
Mehr zu Fourier Analysis and Filtering finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!