factor.scope {stats} | R Documentation |
add.scope
and drop.scope
compute those terms that can be
individually added to or dropped from a model while respecting the
hierarchy of terms.
add.scope(terms1, terms2) drop.scope(terms1, terms2) factor.scope(factor, scope)
terms1 |
the terms or formula for the base model. |
terms2 |
the terms or formula for the upper (add.scope ) or
lower (drop.scope ) scope. If missing for drop.scope it is
taken to be the null formula, so all terms (except any intercept) are
candidates to be dropped. |
factor |
the "factor" attribute of the terms of the base object. |
scope |
a list with one or both components drop and
add giving the "factor" attribute of the lower and
upper scopes respectively. |
factor.scope
is not intended to be called directly by users.
For add.scope
and drop.scope
a character vector of
terms labels. For factor.scope
, a list with components
drop
and add
, character vectors of terms labels.
add.scope( ~ a + b + c + a:b, ~ (a + b + c)^3) # [1] "a:c" "b:c" drop.scope( ~ a + b + c + a:b) # [1] "c" "a:b"