Piecewise Polynomial Spline Representation

Description

Create the piecewise polynomial representation of a spline object.

Usage

polySpline(object, ...)
as.polySpline(object, ...)

Arguments

Value

An object that inherits from class polySpline. This is the piecewise polynomial representation of a univariate spline function. It is defined by a set of distinct numeric values called knots. The spline function is a polynomial function between each successive pair of knots. At each interior knot the polynomial segments on each side are constrained to have the same value of the function and some of its derivatives.

Author(s)

Douglas Bates and Bill Venables

See Also

interpSpline, periodicSpline, splineKnots, splineOrder

Examples

require(graphics)
ispl <- polySpline(interpSpline( weight ~ height,  women, bSpline = TRUE))
print( ispl )   # print the piecewise polynomial representation
plot( ispl )    # plots over the range of the knots
points( women$height, women$weight )

Results

R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(splines)
> png(filename="/home/ddbj/snapshot/RGM3/R_rel/result/splines/polySpline.Rd_%03d_medium.png", width=480, height=480)
> ### Name: polySpline
> ### Title: Piecewise Polynomial Spline Representation
> ### Aliases: polySpline as.polySpline
> ### Keywords: models
> 
> ### ** Examples
> 
> require(graphics)
> ispl <- polySpline(interpSpline( weight ~ height,  women, bSpline = TRUE))
> print( ispl )   # print the piecewise polynomial representation
polynomial representation of spline for weight ~ height
   constant   linear   quadratic       cubic
58      115 1.731918  0.00000000  0.26808191
59      117 2.536164  0.80424574 -0.34040957
60      120 3.123427 -0.21698298  0.09355638
61      123 2.970130  0.06368616 -0.03381595
62      126 2.996054 -0.03776168  0.04170740
63      129 3.045653  0.08736054 -0.13301367
64      132 2.821333 -0.31168048  0.49034728
65      135 3.669014  1.15936136 -0.82837545
66      139 3.502610 -1.32576498  0.82315452
67      142 3.320544  1.14369857 -0.46424262
68      146 4.215213 -0.24902928  0.03381595
69      150 3.818603 -0.14758144  0.32897883
70      154 4.510376  0.83935505 -0.34973127
71      159 5.139893 -0.20983876  0.06994625
72      164 4.930054  0.00000000  0.00000000
> plot( ispl )    # plots over the range of the knots
> points( women$height, women$weight )
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>