Extract Grouping Formula
Usage
getGroupsFormula(object, asList)
Arguments
object
|
any object from which a formula can be extracted.
|
asList
|
an optional logical value. If TRUE the returned
value with be a list of formulas; else, if FALSE the returned
value will be a one-sided formula. Defaults to FALSE .
|
Description
The conditioning expression associated with formula(object)
(i.e. an expression after a |
operator) is returned either as
a named list of one-sided formulas, or a single one-sided formula,
depending on the value of asList
. The components of the
returned list are ordered from outermost to innermost level and are
named after the grouping factor expression.Value
a one-sided formula, or a list of one-sided formulas, with the
grouping structure associated with formula(object)
. If no
conditioning expression is present in formula(object)
a
NULL
value is returned.Author(s)
Jose Pinheiro and Douglas BatesSee Also
getGroups
Examples
library(lme)
getGroupsFormula(y ~ x | g1/g2)