Usage
getCovariate(object, form, data)
getCovariateFormula(object)
getGroups(object, form, level, data, sep, ...)
getGroupsFormula(object, asList, sep)
getResponse(object, form)
getResponseFormula(object)
subFormula(form, pos)
splitFormula(form, sep)
Arguments
object
a formula or an object that can provide a formula
form
an optional formula with a conditioning expression on its
right hand side (i.e. an expression involving the |
operator). Defaults to formula(object).
level
a positive integer vector with the level(s) of grouping to
be used when multiple nested levels of grouping are present. This
argument is optional for most methods of this generic function and
defaults to all levels of nesting.
data
a data frame in which to interpret the variables named in
form. Optional for most methods.
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.
sep
character, the separator to use between group levels when
multiple levels are collapsed. Defaults to '/'.
pos
the integer index of the component of the formula to
return. Defaults to 2.
...
Optional arguments that are passed to some methods. None
used at present.