Hello,

Im making research on humans gait and I found some troubles with matlab. I need given data in file pass through Fast fourier transformation. In given file taken column as X axe are samples of acceleration (which varies depending on movement). Frequence of device is 120Hz. In figure1 X axe is Time(s), Y axe is Acceleration(m/s^2) The main matter is how to make Spectrum of this Acceleration wave that in X axe would be Frequence and in Y axe would be Acceleration.



I inlcuded data text file named MTbeapsisukimo2:

http://www.megafileupload.com/en/file/434206/MTbea...

Theres the code where I was trying to make X axe - as a frequence and Y axe as a Power:



accX=MTbeapsisukimo2(:,9); %X Acceleration

accX=single(accX); % One Array


Fs=120; % Sampling frequency

t=0:1/Fs:22.945; % Time vector of 22.945 seconds

x=accX;

nfft=2754; % Length of FFT

% Take fft, padding with zeros so that length(X)is equal to nfft

X=fft(x,nfft);

% Take the magnitude of fft of x

mx=abs(X);

% Frequency vector

f=(0:nfft-1)*Fs/nfft;

% Generate the plot, title and labels.

figure(1)

plot(t,x)

title('Acceleration Wave Signal');

xlabel('Time (s)');

ylabel('Acceleration');

figure(2)

plot(f,mx)

title('Power Spectrum of a Acceleration Wave');

xlabel('Frequency (Hz)');

ylabel('Power');



I would be very thankfull for any consultation :)