Cross-term averaged FFT.
FD = ctafft(TD,Averages) FD = ctafft(TD,Averages,N)
ctafft takes a time-domain signal TD as input and computes
the cross-term averaged FFT. For this, ctafft computes the FFTs
of TD(Averages(i):end) for all i and sums up their magnitudes.
If Averages is a number, it is a shortcut for 1:Averages.
ctafft helps to get rid of dead-time artifacts in simple FFTs
of ESEEM spectral data. The quality of the result can be very sensitive
to Averages, so it is worthwhile to experiment a bit.
If N is given, all signals are zero-filled to length N
before the FFT. If not given, N is set to the length of TD.
TD can be either a vector or a matrix. In the latter case,
ctafft works along columns.
ctafft implements a procedure introduced in