How to aplly a function to all columns?
2 views (last 30 days)
Show older comments
Hi guys, i have a code which do fft, however are so many columns to apply this code i need a way to do it faster, i already see something about cellfun, but this did't work. my data comes from vibration, I have a column of time and the rest of vibration data.
the following function makes the fft, psd now i want to apply to all columns of an excel table (csv).
function [freq_ax,fft_ax, psd_ax] = my_fft(t,ax)
%% computando fft
dt = mean(diff(t));
n = length(t);
L = 1:floor(n/2);
freq = 1/(dt*n)*(0:n-1);
fhat = (fft(ax,n)*1/(n-1));
fft_ax = abs(fhat(L));
freq_ax = (freq(L));
psd = fhat.*conj(fhat);
psd_ax = psd(L);
end
0 Comments
Answers (1)
dpb
on 22 Jan 2023
"fft(X) is the discrete Fourier transform (DFT) of vector X. For matrices, the fft operation is applied to each column."
Hence, you get the operations applied to all columns for free; just pass the vibration data array (without augmenting it with the time which is of no import for the FFT, all you need is the sample rate) to FFT and operate by column for the rest. You'll get N PSDs; one per column.
0 Comments
See Also
Categories
Find more on Fourier Analysis and Filtering in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!