crs: Bases for cubic regression splines (equivalent to "cr" in...

In survPen: Multidimensional Penalized Splines for Survival and Net Survival Models

Bases for cubic regression splines (equivalent to "cr" in mgcv)

Description

Builds the design matrix and the penalty matrix for cubic regression splines.

Usage

crs(x, knots = NULL, df = 10, intercept = TRUE)

Arguments

x	Numeric vector
knots	Numeric vectors that specifies the knots of the splines (including boundaries); default is NULL
df	numeric value that indicates the number of knots desired (or degrees of freedom) if knots=NULL; default is 10
intercept	if FALSE, the intercept is excluded from the basis; default is TRUE

Details

See package mgcv and section 4.1.2 of Wood (2006) for more details about this basis

Value

List of three elements

bs	design matrix
pen	penalty matrix
knots	vector of knots (specified or calculated from df)

References

Wood, S. N. (2006), Generalized additive models: an introduction with R. London: Chapman & Hall/CRC.

Examples

x <- seq(1,10,length=100)
# natural cubic spline with 3 knots
crs(x,knots=c(1,5,10))

survPen documentation built on Sept. 14, 2023, 1:06 a.m.