R: Extract functional coefficients

coef.fd {fda} | R Documentation

## Extract functional coefficients

### Description

Obtain the coefficients component from a functional object (functional data, class `fd`, functional parameter, class `fdPar`, a functional smooth, class `fdSmooth`, or a Taylor spline representation, class `Taylor`.

### Usage

    ## S3 method for class 'fd'
    coef(object, ...)
    ## S3 method for class 'fdPar'
    coef(object, ...)
    ## S3 method for class 'fdSmooth'
    coef(object, ...)
    ## S3 method for class 'Taylor'
    coef(object, ...)
    ## S3 method for class 'fd'
    coefficients(object, ...)
    ## S3 method for class 'fdPar'
    coefficients(object, ...)
    ## S3 method for class 'fdSmooth'
    coefficients(object, ...)
    ## S3 method for class 'Taylor'
    coefficients(object, ...)

### Arguments

`object` | An object whose functional coefficients are desired
`...` | other arguments

### Details

Functional representations are evaluated by multiplying a basis function matrix times a coefficient vector, matrix or 3-dimensional array. (The basis function matrix contains the basis functions as columns evaluated at the `evalarg` values as rows.)

### Value

A numeric vector or array of the coefficients.

### See Also

`coef` `fd` `fdPar` `smooth.basisPar` `smooth.basis`

### Examples

    ##
    ## coef.fd
    ##
    bspl1.1 <- create.bspline.basis(norder=1, breaks=0:1)
    fd.bspl1.1 <- fd(0, basisobj=bspl1.1)
    coef(fd.bspl1.1)

    ##
    ## coef.fdPar
    ##
    rangeval <- c(-3,3)
    #  set up some standard normal data
    x <- rnorm(50)
    #  make sure values within the range
    x[x < -3] <- -2.99
    x[x >  3] <-  2.99
    #  set up basis for W(x)
    basisobj <- create.bspline.basis(rangeval, 11)
    #  set up initial value for Wfdobj
    Wfd0 <- fd(matrix(0,11,1), basisobj)
    WfdParobj <- fdPar(Wfd0)

    coef(WfdParobj)

    ##
    ## coef.fdSmooth
    ##

    girlGrowthSm <- with(growth, smooth.basisPar(argvals=age, y=hgtf,
                                                 lambda=0.1)$fd)
    coef(girlGrowthSm)

    ##
    ## coef.Taylor
    ##
    # coming soon.

[Package fda version 2.4.8 Index]