I have 6 column vectors $(\mathbf A_x,\mathbf A_y, \mathbf A_z, \mathbf G_x, \mathbf G_y, \mathbf G_z)$ taken by accelerometer to analyze the vibration of a construction. Each column is a $64998\times 1$ valued-vector and overall time is $664$ seconds. I've done something but I don't know how I can fix it.
Fs=97.885; L=64998; NFFT=2^nextpow2(64998); AXdft = fft(Ax); AXdft=AXdft(1:NFFT/2+1,:); freq = linspace(0,Fs,NFFT/2+1); plot(freq,2*abs(AXdft)); xlabel('Hz');ylabel('Magnitude'); figure; plot(freq,20*log10(abs(AXdft))); xlabel('Hz');ylabel('dB'); title('Plot in dB');
BTW I will add each column over other via
getting a figure but missing its size. The frequency doesn't appear in figure and I guess I must do PSD, Can anyone help?