Y = fft(X)
Y = fft(X, n)
Y = fft(X, n, dim)
| Parameter | Description |
|---|---|
| X | a vector, matrix or N-D array (double, single, integer, logical). |
| n | transform length: a non negative integer scalar or [] (default). |
| dim | dimension: a positive integer scalar. |
| Parameter | Description |
|---|---|
| Y | a vector, matrix, N-D array: frequency domain representation. |
fft(X) computes the discrete Fourier transform of X using a Fast Fourier Transform (FFT) algorithm based on FFTW library.
% Sampling frequency
Fs = 150;
% Time vector of 1 second
t = 0:1*inv(Fs):1;
% Creates a sine wave of f Hz.
f = 5;
x = sin(2 * pi * t * f);
% Length of FFT
nfft = 1024;
% Take fft, padding with zeros so that length(X) is equal to nfft
X = fft(x, nfft)
% FFT is symmetrix
X = X(1:nfft*inv(2))
% Frequency vector
f = (0:nfft *inv(2) -1)*Fs * inv(nfft);
| Version | Description |
|---|---|
| 1.0.0 | initial version |