splinek: Tool to approximate functions by natural cubic splines
Description
splinek is used to build the incidence matrix, the penalty matrix as well as other interest matrices to approximate functions by natural cubic splines.
Usage
splinek(x,xx)
Arguments
xx
knots of the natural cubic spline, it is a set (ordered ascending) formed by the different values of t in the sample.
x
values of the explanatory variable t.
Value
ssa list with the incidence matrix, the penalty matrix as well as other interest matrices.
References
Green, P.J. and Silverman, B.W. (1994) Nonparametric Regression and Generalized Linear Models, Boca Raton: Chapman and Hall.