Calculate basis vectors to estimate FRF using SVD
[f,mcoh] = frf_svd(spp,sqp,asd,ref)
FRF_SVD uses singular value decomposition to estimate FRF and multiple coherence. The P-set is the set of DOF for the basis vectors which are part of the singular value decomposition, and the Q-set specifies the rest of the channels.
SPP is a matrix of size MxM of imat_fn containing the P-set Cross Spectra for all of the channels used in the basis vectors. It can be an output from spFRF.
SQP is a matrix of size MxN of imat_fn containing the Q-set to P-set response Cross Spectra. It can be an output from spFRF. It is empty if all of the DOF are in the P-set.
ASD is a matrix of imat_fn containing the Auto Spectral Densities for all of the DOF in the P- and Q-sets. It is used to calculate the multiple coherence of both reference and response channels, and is also used to label the otuput FRF ordinate attributes correctly.
REF is an imat_ctrace containing the DOF that define the references.
F is an imat_fn containing the FRF matrix.
MCOH is an imat_fn containing the coherence functions for all of the channels.
spfrf, imat_fn/csd, imat_fn/psd, imat_fn/frf