ps {DPpackage}R Documentation

Specify a smoothing spline fit in a PSgam formula

Description

A symbolic wrapper to indicate a smooth term in a formula argument to PSgam

Usage

ps(..., k=50,degree=3,pord=1)

Arguments

... the predictors.
k an integer giving the number of intervals for B-splines.
degree an integer giving the degree of the B-splines.
pord an integer giving the order of difference penalty.

Value

ps returns the vectors of predictors, endowed with a number of attributes. The vector itself is used in the construction of the model matrix.
Note that ps does not do the smoothing; it simply sets things up for PSgam.

Author(s)

Alejandro Jara <ajarav@udec.cl>

References

Eilers, P.H.C. and Marx, B.D. (1996) Flexible Smoothing with B-splines and penalties. Statistical Science, 11(2): 89-121.

Examples

   # fit Start using a smoothing spline with 4 df.
     y ~ Age + s(Start, degree=4)
   # fit log(Start) using a smoothing spline with 5 df.
     y ~ Age + s(log(Start), degree=5)

[Package DPpackage version 1.0-7 Index]