Compute the discrete Fourier transform of x using a Fast Fourier Transform (FFT) algorithm.
The FFT is calculated along the first non-singleton dimension of the
array. Thus if x is a matrix, fft (x) computes the
FFT for each column of x.
If called with two arguments, n is expected to be an integer specifying the number of elements of x to use, or an empty matrix to specify that its value should be ignored. If n is larger than the dimension along which the FFT is calculated, then x is resized and padded with zeros. Otherwise, if n is smaller than the dimension along which the FFT is calculated, then x is truncated.
If called with three arguments, dim is an integer specifying the dimension of the matrix along which the FFT is performed.
See also: ifft, fft2, fftn, fftw.
Package: communications