Arguments
object
an object inheriting from class varFunc
,
representing a variance function structure.
form
an optional formula with a conditioning expression on its
right hand side (i.e. an expression involving the |
operator). Defaults to formula(object)
. Not used.
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. Not used.
data
a data frame in which to interpret the variables named in
form
. Optional for most methods. Not used.
sep
character, the separator to use between group levels when
multiple levels are collapsed. The default is '/'
. Not used.