| % File src/library/stats/man/factor.scope.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2007 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{factor.scope} |
| \title{Compute Allowed Changes in Adding to or Dropping from a Formula} |
| \usage{ |
| add.scope(terms1, terms2) |
| |
| drop.scope(terms1, terms2) |
| |
| factor.scope(factor, scope) |
| } |
| \alias{add.scope} |
| \alias{drop.scope} |
| \alias{factor.scope} |
| \arguments{ |
| \item{terms1}{the terms or formula for the base model.} |
| \item{terms2}{the terms or formula for the upper (\code{add.scope}) or |
| lower (\code{drop.scope}) scope. If missing for \code{drop.scope} it is |
| taken to be the null formula, so all terms (except any intercept) are |
| candidates to be dropped.} |
| \item{factor}{the \code{"factor"} attribute of the terms of the base object.} |
| \item{scope}{a list with one or both components \code{drop} and |
| \code{add} giving the \code{"factor"} attribute of the lower and |
| upper scopes respectively.} |
| } |
| \description{ |
| \code{add.scope} and \code{drop.scope} compute those terms that can be |
| individually added to or dropped from a model while respecting the |
| hierarchy of terms. |
| } |
| \details{ |
| \code{factor.scope} is not intended to be called directly by users. |
| } |
| \value{ |
| For \code{add.scope} and \code{drop.scope} a character vector of |
| terms labels. For \code{factor.scope}, a list with components |
| \code{drop} and \code{add}, character vectors of terms labels. |
| } |
| |
| \seealso{\code{\link{add1}}, \code{\link{drop1}}, |
| \code{\link{aov}}, \code{\link{lm}}} |
| |
| \examples{ |
| 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" |
| } |
| \keyword{models} |