Produce model matrices or penalty matrices for a tensor product smooth from the model matrices or penalty matrices for the marginal bases of the smooth.
a list of model matrices for the marginal bases of a smooth
X[[m]] are the model matrices of the marginal bases of
a tensor product smooth then the ith row of the model matrix for the whole tensor product smooth is given by
X[][i,]%x%X[][i,]%x% ... X[[m]][i,], where
%x% is the Kronecker product. Of course
the routine operates column-wise, not row-wise!
Either a single model matrix for a tensor product smooth, or a list of penalty terms for a tensor product smooth.
Simon N. Wood firstname.lastname@example.org
Wood, S.N. (2006) “Low Rank Scale Invariant Tensor Product Smooths for Generalized Additive Mixed Models”. Biometrics 62(4):1025-1036