fda (version 2.4.4)

evaldiag.bifd: Evaluate the Diagonal of a Bivariate Functional Data Object

Description

Bivariate function data objects are functions of two arguments, $f(s,t)$. It can be useful to evaluate the function for argument values satisying $s=t$, such as evaluating the univariate variance function given the bivariate function that defines the variance-covariance function or surface. A linear differential operator can be applied to function $f(s,t)$ considered as a univariate function of either object holding the other object fixed.

Usage

evaldiag.bifd(evalarg, bifdobj, sLfd=int2Lfd(0),
                                tLfd=int2Lfd(0), returnMatrix=FALSE)

Arguments

evalarg

a vector of values of $s = t$.

bifdobj

a bivariate functional data object of the bifd class.

sLfd

either a nonnegative integer or a linear differential operator object.

tLfd

either a nonnegative integer or a linear differential operator object.

returnMatrix

logical: If TRUE, a two-dimensional is returned using a special class from the Matrix package.

Value

a vector or matrix of diagonal function values.

See Also

var.fd, eval.bifd