Piecewise Polynomial Spline Representation

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Description

Create the piecewise polynomial representation of a spline object.

Usage

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

Arguments

object

An object that inherits from class spline.

...

Optional additional arguments. At present no additional arguments are used.

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

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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 )