Estimates the A and C matrix in a discrete-time state-space model from frequency response function (FRF) data that was preprocessed by fdordom.
[A,C] = fdmodom(R,n)
This function estimates the A and C matrices corresponding to an n th order discrete-time LTI state-space model. The compressed data matrix R from the preprocessor function fdordom is used to this end.
R is a compressed data matrix containing information about the measured data, as well as information regarding the system dimensions.
n is the desired model order n.
A is the state-space model's A matrix.
C is the state-space model's C matrix.
The data matrix obtained with fcordom contains the weighted left singular vectors of a matrix similar to the R22 matrix (see fdordom). The first n of these vectors form an estimate Os of the system's extended observability matrix:
The estimates Ahat and Chat are obtained by linear regression:
This a top-level function that is used directly by the user.