ibr (version 2.0-2)

DuchonQ: Computes the semi-kernel of Duchon splines

Description

The function DuchonQ computes the semi-kernel of Duchon splines. This function is not intended to be used directly.

Usage

DuchonQ(x,xk,m=2,s=0,symmetric=TRUE)

Arguments

x

A numeric matrix of explanatory variables, with n rows and p columns.

xk

A numeric matrix of explanatory variables, with nk rows and p columns.

m

Order of derivatives.

s

Exponent for the weight function.

symmetric

Boolean: if TRUE only x is used and it computes the semi-kernel at observations of x (it should give the same result as DuchonQ(x,xk,m,s,FALSE)).

Value

The semi-kernel evaluated.

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.

See Also

ibr