The conditioning expression associated with formula(object)
(i.e. the expression after the | 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.
Usage
getGroupsFormula(object, asList, sep)
Arguments
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.