fda (version 2.4.0)

bifd: Create a bivariate functional data object

Description

This function creates a bivariate functional data object, which consists of two bases for expanding a functional data object of two variables, s and t, and a set of coefficients defining this expansion. The bases are contained in "basisfd" objects.

Usage

bifd (coef=matrix(0,2,1), sbasisobj=create.bspline.basis(),
      tbasisobj=create.bspline.basis(), fdnames=defaultnames)

Arguments

coef

a two-, three-, or four-dimensional array containing coefficient values for the expansion of each set of bivariate function values=terms of a set of basis function values

If 'coef' is two dimensional, this implies that there is only one v

sbasisobj

a functional data basis object for the first argument s of the bivariate function.

tbasisobj

a functional data basis object for the second argument t of the bivariate function.

fdnames

A list of length 4 containing dimnames for 'coefs' if it is a 4-dimensional array. If it is only 2- or 3-dimensional, the later components of fdnames are not applied to 'coefs'. In any event, the components of fdnames describe the following:

Value

• A bivariate functional data object = a list of class 'bifd' with the following components:
• coefs
  the input 'coefs' possible with dimnames from dfnames if provided or from sbasisobj$names and tbasisobsj$names
• sbasisobj
  a functional data basis object for the first argument s of the bivariate function.
• tbasisobj
  a functional data basis object for the second argument t of the bivariate function.
• bifdnames
  a list of length 4 giving names for the dimensions of coefs, with one or two unused lists of names if length(dim(coefs)) is only two or one, respectively.

See Also

basisfd objAndNames

Examples

Bspl2 <- create.bspline.basis(nbasis=2, norder=1)
Bspl3 <- create.bspline.basis(nbasis=3, norder=2)

(bBspl2.3 <- bifd(array(1:6, dim=2:3), Bspl2, Bspl3))
str(bBspl2.3)