These function calculates the generalized cross-validation criterion for the
smoothing parameters \(\alpha_v\) or \(\alpha_w\) that are used in the
FCP_TPA
algorithm. As the criterion is symmetric in \(v\) and
\(w\), this function implements a generic criterion, which is called by
findAlphaVopt
, findAlphaWopt
with the correct values.
gcv(alpha, n, z, eta, lambda)
The value of the GCV criterion.
The current value of the smoothing parameter.
The length of the dimension, for which the smoothing parameter is to be optimized.
A vector of length n
. See Details.
A vector of length n
. See Details.
A vector of length n
, containing the eigenvalues of the
penalty matrix corresponding the the current image direction.
The criterion can be evaluated in a numerically efficient way, adopting the ideas in Huang, Shen and Buja (2008) to three-ways tensors. TODO!
G. I. Allen, "Multi-way Functional Principal Components Analysis", IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing, 2013.
FCP_TPA