Level of excitation of input signals
Ped = pexcit(Data)
[Ped.Maxnr] = pexcit(Data,Maxnr,Threshold)
Ped = pexcit(Data) tests the degree of
persistence of excitation for the input. Data is
an iddata object with time- or frequency-domain
signals. Ped is the degree or order of excitation
of the inputs in Data and is a row vector of integers
with as many components as there are inputs in Data.
The intuitive interpretation of the degree of excitation in an input
is the order of a model that the input is capable of estimating in
an unambiguous way.
[Ped.Maxnr] = pexcit(Data,Maxnr,Threshold) specifies
the maximum order tested and threshold level used to measure which
singular values are significant. Default value of Maxnr is min(N/3,50),
where N is the number of input data. Default value
of Threshold is 1e-9.
Section 13.2 in Ljung (1999).