crs.FP {survPen}

Penalty matrix constructor for cubic regression splines

Description

constructs the penalty matrix associated with cubic regression splines basis. This function is called inside crs.

Usage

crs.FP(knots, h)

Arguments

knots

Numeric vectors that specifies the knots of the splines (including boundaries)

h

vector of knots differences (corresponds to diff(sort(knots)))

Value

List of two elements:

F.mat

matrix used in function crs for basis construction

P.mat

penalty matrix

Examples

library(survPen)

# construction of the penalty matrix using a sequence of knots
knots <- c(0,0.25,0.5,0.75,1)
diff.knots <- diff(knots)

crs.FP(knots,diff.knots)