The R Project SVN R

\name{detach}
\title{Detach Objects from the Search Path}
\usage{
detach(name, pos = 2, version)
}
\alias{detach}
\arguments{
  \item{name}{
    The object to detach.  Defaults to \code{search()[pos]}.
    This can be an unquoted name or a character string but \emph{not} a
    character vector.  If a number is supplied this is taken as \code{pos}.
  }
  \item{pos}{
    Index position in \code{\link{search}()} of database to
    detach.  When \code{name} is a number, \code{pos = name}
    is used.
  }
  \item{version}{A character string denoting a version number of the
    package to be removed.  This should be used only with a versioned
    installation of the package: see \code{\link{library}}.}
}
\description{
  Detach a database, i.e., remove it from the \code{\link{search}()} path
  of available \R objects.  Usually, this is either a \code{\link{data.frame}}
  which has been \code{\link{attach}}ed or a package which was required
  previously.
}
\details{
  This most commonly used with a single number argument referring to a
  position on the search list, and can also be used with a unquoted or
  quoted name of an item on the search list such as \code{package:tools}.

  When a package have been loaded with an explicit version number it can
  be detached using the name shown by \code{\link{search}} or by
  supplying \code{name} and \code{version}: see the examples.
}
\value{
  The attached database is returned invisibly, either as
  \code{\link{data.frame}} or as \code{\link{list}}.
}
\note{
  You cannot detach either the workspace (position 1) or the \pkg{base}
  package (the last item in the search list).
}
\references{
  Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988)
  \emph{The New S Language}.
  Wadsworth \& Brooks/Cole.
}
\seealso{
  \code{\link{attach}}, \code{\link{library}}, \code{\link{search}},
  \code{\link{objects}}.
}
\examples{
require(splines)#package
detach(package:splines)
## could equally well use detach("package:splines")
## but NOT  pkg <- "package:splines"; detach(pkg)
## Instead, use
library(splines)
pkg <- "package:splines"
detach(pos = match(pkg, search()))

## careful: do not do this unless 'splines' is not already loaded.
library(splines)
detach(2)# 'pos' used for 'name'

\dontrun{## Using a versioned install
library(ash, version="1.0-9")  # or perhaps just library(ash)
# then one of
detach("package:ash", version="1.0-9")
# or
detach("package:ash_1.0-9")
}}
\keyword{data}