FFT and plot amplitude spectrum
3 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
Samaneh Arzpeima
am 6 Dez. 2018
Kommentiert: Shubham Gupta
am 10 Dez. 2018
hello everybody
I got stuck on this problem and really need your help
I must plot the amplitude spectrum of a data set. my data set is the attached “momentrate.mat”. The first column is ‘time(s)’ and the second one is ‘momentrate(Nm/s)’.these 2 columns give a plot like the left figure in attached pdf file.by
plot(momentrate(:,1),momentrate(:,2))
now I need to take the amplitude spectrum of the above plot, and it should be something like the right figure in attached pdf file.
I tried the following codes
y=momentrate(:,2);
t=momentrate(:,1);
dt=diff(t)
sample_frequency= numel(t)/(t(end)-t(1))
nfft=2^nextpow2(length(y));
Y=fft(y,nfft);
Y=Y(1:nfft/2);
m=abs(Y);
f=(0:nfft/2-1)*sample_frequency/nfft;
plot(f,m);
but this won't give me anything like what I suppose to have.
Can you please tell me what is wrong?
I would appreciate if you could explain to me with simple codes.
0 Kommentare
Akzeptierte Antwort
Shubham Gupta
am 7 Dez. 2018
You might wanna use "logarithmic plot" instead of simple plot. So last line would be
loglog(f,m);
Weitere Antworten (0)
Siehe auch
Kategorien
Mehr zu Spectral Measurements finden Sie in Help Center und File Exchange
Produkte
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!