nlme (version 3.1-1)

getGroups.varFunc: Extract varFunc Groups

Description

This method function extracts the grouping factor associated with the variance function represented by object, if any is present.

Usage

getGroups(object)

Arguments

object

an object inheriting from class varFunc, representing a variance function structure.

Value

• if object has a groups attribute, its value is returned; else NULL is returned.

Examples

data(Orthodont)
vf1 <- varPower(form = ~ age | Sex)
vf1 <- initialize(vf1, Orthodont)
getGroups(vf1)