| tensor.prod.model.matrix {crs} | R Documentation |
Utility functions for constructing tensor product smooths
Description
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.
Usage
tensor.prod.model.matrix(X)
Arguments
X |
a list of model matrices for the marginal bases of a smooth |
Details
If X[[1]], X[[2]] ... 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[[1]][i,]%x%X[[2]][i,]%x% ... X[[m]][i,], where %x% is the Kronecker product. Of course
the routine operates column-wise, not row-wise!
Value
Either a single model matrix for a tensor product smooth, or a list of penalty terms for a tensor product smooth.
Author(s)
Simon N. Wood simon.wood@r-project.org
References
Wood, S.N. (2006) “Low Rank Scale Invariant Tensor Product Smooths for Generalized Additive Mixed Models”. Biometrics 62(4):1025-1036
See Also
te, smooth.construct.tensor.smooth.spec
Examples
X <- list(matrix(1:4,2,2),matrix(5:10,2,3))
tensor.prod.model.matrix(X)