FFT of single max sided from signal
3 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Ramesh Bala
le 17 Mar 2021
Commenté : Mathieu NOE
le 17 Mar 2021
I'm trying to get frequency of signal.But after applying FFT it doesn't shows 200e3 (which is given) ?
Attaching the code and picture how the end result should be.
Thanks
load ('T1.mat')
f = 200e3; % frequency
T = 1/f ;
sf = 1/t(1,2);
n =5;
tt = n*T;
t1 = 0:1/sf:tt; % total time cycle
sinewave = sin(2*pi*f*t);
figure(1)
plot(t,sinewave)
%fourier
figure
xdft = fft(sinewave,1024);
plot(abs(xdft))
0 commentaires
Réponse acceptée
Mathieu NOE
le 17 Mar 2021
hello
this is the code fixed :
FYI, the frequency in your code is 200 and not 100 kHz as in image , but you can easily change that
cheers
clc
clearvars
load ('T1.mat')
f = 200e3; % frequency
T = 1/f ;
sf = 1/t(1,2);
n =5;
tt = n*T;
t1 = 0:1/sf:tt; % total time cycle
sinewave = sin(2*pi*f*t);
figure(1)
plot(t,sinewave)
%fourier
nfft = 1024;
xdft = fft(sinewave,nfft);
% one sidded fft spectrum % Select first half
if rem(nfft,2) % nfft odd
select = (1:(nfft+1)/2)';
else
select = (1:nfft/2+1)';
end
xdft = xdft(select)*2/nfft;
freq_vector = (select - 1)*sf/nfft;
figure
plot(freq_vector/1000,abs(xdft)) % freq divided by 1000 to be displayed in kHz
xlabel('kHz');
ylabel('Amplitude');
xlim([0 2*f/1000]);
2 commentaires
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Spectral Measurements dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!