Transform iddata objects from time to frequency domain using a Fast Fourier Transform (FFT) algorithm.
Inputs
iddata set containing signals in time-domain.
Length of the FFT transformations. If n does not match the signal length, the signals in dat are shortened or padded with zeros. n is a vector with as many elements as there are experiments in dat or a scalar with a common length for all experiments. If not specified, the signal lengths are taken as default values.
Outputs
iddata identification dataset in frequency-domain. In order to preserve signal power and noise level, the FFTs are normalized by dividing each transform by the square root of the signal length. The frequency values are distributed equally from 0 to the Nyquist frequency. The Nyquist frequency is only included for even signal lengths.
Package: control