The R Project SVN R

\name{showMethods}
\alias{showMethods}
\title{ Show all the methods for the specified function(s)}
\description{
  Show a summary of the methods for one or more generic functions,
  possibly restricted to those involving specified classes.
}
\usage{
showMethods(f=character(), where=-1, classes=NULL, includeDefs=FALSE, 
            inherited=TRUE, printTo = stdout())
}
\arguments{
  \item{f}{ One or more function names.  If omitted, all functions
    will be examined. }
  \item{where}{If \code{where} is supplied, the methods definition from
    that position will be used; otherwise, the current definition is
    used (which will include inherited methods that have arisen so far
    in the session). If \code{f} is omitted, \code{where} controls
    where to look for generic functions.} 
  \item{classes}{ If argument \code{classes} is supplied, it is a vector
    of class names that restricts the displayed results to those methods
    whose signatures include one or more of those classes. }
  \item{includeDefs}{ If \code{includeDefs} is \code{TRUE}, include the
    definitions of the individual methods in the printout. }
  \item{inherited}{ If \code{inherits} is \code{TRUE}, then methods that
    have been found by inheritance, so far in the session, will be
    included and marked as inherited. } 
  \item{printTo}{The connection on which the printed information will be
    written.  If \code{printTo} is \code{FALSE}, the output will be
    collected as a character vector and returned as the value of the
    call to \code{showMethod}.   See \code{\link{show}}.
  }
}
\details{
  The output style is different from S-Plus in that it does not show the
  database from which the definition comes, but can optionally include
  the method definitions.
}
\value{
  If \code{printTo} is \code{FALSE}, the character vector that would
  have been printed is returned; otherwise the value is the connection
  or filename.
}
\references{
  The web page \url{http://www.omegahat.org/RSMethods/index.html} is the
  primary documentation.

  The functions in this package emulate the facility for classes and
  methods described in \emph{Programming with Data} (John M. Chambers,
  Springer, 1998).  See this book for further details and examples.
}
\author{
  John Chambers
}
\seealso{
  \code{\link{setMethod}}, and \code{\link{GenericFunctions}}
  for other tools involving methods;
  \code{\link{show}}
}
\examples{
\testonly{
setClass("track",
            representation(x="numeric", y="numeric"))
## First, with only one object as argument:
setMethod("plot", signature(x="track", y="missing"),
  function(x,  y, ...) plot(slot(x, "x"), slot(x, "y"), ...)
)
## Second, plot the data from the track on the y-axis against anything
## as the x data.
setMethod("plot", signature(y = "track"),
 function(x, y, ...) plot(x, slot(y, "y"), ...)
)
setMethod("plot", "track",
 function(x, y, ...) plot(slot(x, "y"), y,  ...)
)
}
## assuming the methods for plot
## are set up as in the documentation for setMethod,
## print (without definitions) the methods that involve
## class "track"
showMethods("plot", classes = "track")
\dontrun{
Function "plot":
x = ANY, y = track
x = track, y = missing
x = track, y = ANY}
}
\keyword{methods}