Compute the n-by-n Fourier transformation matrix. This is
the matrix d such that the Fourier transform of a column vector of
length n is given by dftmtx(n) * x and the
inverse Fourier transform is given by inv(dftmtx(n)) * x.
In general this is less efficient than calling the fft and
ifft functions directly.
See also: fft, ifft.
Package: communications