ibr (version 1.4.5)

dsSx: 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

dsSx(X,Xetoile,m=2,s=0)

Value

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

Details

see the reference for detailed explanation of Q (the semi kernel) and S (the polynomial null space).

References

Duchon, J. (1977) Splines minimizing rotation-invariant semi-norms in Solobev spaces. in W. Shemp and K. Zeller (eds) Construction theory of functions of several variables, 85-100, Springer, Berlin.

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

See Also

ibr