tpsSx {ibr}R Documentation

Evaluate the smoothing matrix at any point

Description

The function evaluates the matrix Q and S related to the explanatory variables X at any points. This function is not intended to be used directly.

Usage

tpsSx(X,Xetoile,lambda,m=2)

Arguments

X Matrix of explanatory variables, size n,p.
Xetoile Matrix of new observations with the same number of variables as X, size m,p.
lambda Coefficient lambda that control smoothness.
m Order of thin plate splines.

Details

see the reference for detailed explanation of Q (the semi kernel) and S (the polynomial null space). Both matrices are computed using fields.

Value

Returns a list containing two matrices denoted Sgu (for null space) and Qgu

Author(s)

Pierre-Andre Cornillon, Nicolas Hengartner and Eric Matzner-Lober

References

C. Gu (2002) Smoothing spline anova models. New York: Springer-Verlag.

See Also

ibr, fields.mkpoly, Rad.cov


[Package ibr version 1.2 Index]