fft Invalid expression in plot
3 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Alia Hicks
le 28 Juil 2020
Réponse apportée : Alia Hicks
le 28 Juil 2020
I'm recieving error "Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatched delimiters." at the second from last line "plot(t,f,); %amp vs time"
dt = .001;
t = 0:dt:1;
f = data_output;
%%Compute the Fast Fourier Transform FFT
n = length(t);
fhat = fft(f,n); % Compute the fast Fourier transform
PSD = fhat.*conj(fhat)/n; % Power spectrum (power per freq)
freq = 1/(dt*n)*(0:n); % Create x-axis of frequencies in Hz
L = 1:floor(n/2); % Only plot the first half of freqs
%%Use the PSD to filter out noise
indices = PSD>100; % Find all freqs with large power
PSDclean = PSD.*indices; % Zero out all others
fhat = indices.*fhat; % Zero out small Fourier coeffs. in Y
ffilt = ifft(fhat); % Inverse FFT for filtered time signal
%%PLOTS
plot(t,f,); %amp vs time
plot(f,fft); % mag vs freq
0 commentaires
Réponse acceptée
Plus de réponses (1)
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!