# predict.bSpline {splines}

### Description

The `predict`

methods for the classes that inherit from the virtual classes `bSpline`

and `polySpline`

are used to evaluate the spline or its derivatives. The `plot`

method for a spline object first evaluates `predict`

with the `x`

argument missing, then plots the resulting `xyVector`

with `type = "l"`

.

### Usage

## S3 method for class 'bSpline': predict((object, x, nseg = 50, deriv = 0, ...)) ## S3 method for class 'nbSpline': predict((object, x, nseg = 50, deriv = 0, ...)) ## S3 method for class 'pbSpline': predict((object, x, nseg = 50, deriv = 0, ...)) ## S3 method for class 'npolySpline': predict((object, x, nseg = 50, deriv = 0, ...)) ## S3 method for class 'ppolySpline': predict((object, x, nseg = 50, deriv = 0, ...))

### Arguments

- object
- An object that inherits from the
`bSpline`

or the`polySpline`

class. - x
- A numeric vector of
`x`

values at which to evaluate the spline. If this argument is missing a suitable set of`x`

values is generated as a sequence of`nseq`

segments spanning the range of the knots. - nseg
- A positive integer giving the number of segments in a set of equally-spaced
`x`

values spanning the range of the knots in`object`

. This value is only used if`x`

is missing. - deriv
- An integer between 0 and
`splineOrder(object) - 1`

specifying the derivative to evaluate. - ...
- further arguments passed to or from other methods.

### Values

an `xyVector`

with components

- x
- the supplied or inferred numeric vector of
`x`

values - y
- the value of the spline (or its
`deriv`

'th derivative) at the`x`

vector

### See Also

### Examples

require(graphics); require(stats) ispl <- interpSpline( weight ~ height, women ) opar <- par(mfrow = c(2, 2), las = 1) plot(predict(ispl, nseg = 201), # plots over the range of the knots main = "Original data with interpolating spline", type = "l", xlab = "height", ylab = "weight") points(women$height, women$weight, col = 4) plot(predict(ispl, nseg = 201, deriv = 1), main = "First derivative of interpolating spline", type = "l", xlab = "height", ylab = "weight") plot(predict(ispl, nseg = 201, deriv = 2), main = "Second derivative of interpolating spline", type = "l", xlab = "height", ylab = "weight") plot(predict(ispl, nseg = 401, deriv = 3), main = "Third derivative of interpolating spline", type = "l", xlab = "height", ylab = "weight") par(opar)

Documentation reproduced from R 3.0.2. License: GPL-2.