The R Project SVN R

\name{match.call}
\title{Argument Matching}
\usage{
match.call(definition = NULL, call = sys.call(sys.parent()),
           expand.dots = TRUE)
}
\alias{match.call}
\arguments{
  \item{definition}{a function, by default the function from which
    \code{match.call} is called.}
  \item{call}{an unevaluated call to the function specified by
    \code{definition}, as generated by \code{\link{call}}.}
  \item{expand.dots}{logical. Should arguments matching \code{\dots}
    in the call be included or left as a \code{\dots} argument?}
}
\description{
  \code{match.call} returns a call in which all of the arguments are
  specified by their names.  The most common use is to get the call of
  the current function, with all arguments named.
}
\value{
  An object of class \code{call}.
}
\seealso{
  \code{\link{call}}, \code{\link{pmatch}}, \code{\link{match.arg}},
  \code{\link{match.fun}}.
}
\examples{
match.call(get, call("get", "abc", i = FALSE, p = 3))
## -> get(x = "abc", pos = 3, inherits = FALSE)
fun <- function(x, lower = 0, upper = 1) {
  structure((x - lower) / (upper - lower), CALL = match.call())
}
fun(4 * atan(1), u = pi)
}
\keyword{programming}