splines2 (version 0.4.5)

knots: Extract Knots from the Given Object

Description

Methods for the generic function knots from the stats package to obtain internal or boundary knots from the objects produced by this package.

Usage

# S3 method for bSpline2
knots(Fn, type = c("internal", "boundary"), ...)
# S3 method for dbs
knots(Fn, type = c("internal", "boundary"), ...)
# S3 method for ibs
knots(Fn, type = c("internal", "boundary"), ...)
# S3 method for mSpline
knots(Fn, type = c("internal", "boundary"), ...)
# S3 method for iSpline
knots(Fn, type = c("internal", "boundary"), ...)
# S3 method for cSpline
knots(Fn, type = c("internal", "boundary"), ...)
# S3 method for bernsteinPoly
knots(Fn, type = c("internal", "boundary"), ...)
# S3 method for naturalSpline
knots(Fn, type = c("internal", "boundary"), ...)

Value

A numerical vector.

Arguments

Fn

An splines2 object produced by this package.

type

A character vector of length one indicating the type of knots to return. The available choices are "internal" for internal knots and "Boundary" for boundary knots.

...

Optional arguments that are not used now.

Examples

library(splines2)

set.seed(123)
x <- rnorm(100)

## B-spline basis
bsMat <- bSpline(x, df = 8, degree = 3)

## extract internal knots placed based on the quantile of x
(internal_knots <- knots(bsMat))

## extract boundary knots placed based on the range of x
boundary_knots <- knots(bsMat, type = "boundary")
all.equal(boundary_knots, range(x))