The R Project SVN R

\name{help}
\title{Documentation}
\usage{
help(topic, offline = FALSE, package = c(.packages(), .Autoloaded),
     lib.loc = .lib.loc, verbose = .Options$verbose,
     chmhelp = .Options$chmhelp,
     htmlhelp = .Options$htmlhelp, winhelp = .Options$winhelp)
?topic
}
\alias{help}
\alias{?}
\arguments{
    \item{topic}{a name or character string on which documentation is
    sought (but \emph{not} a variable containing a character string!).}
    \item{offline}{a logical indicating whether documentation should be
    displayed on-line to the screen (the default) or hardcopy of it
    should be produced.}
    \item{package}{a name or character vector giving the packages to look
    into for documentation.  By default, all packages in the search path
    are used.}
    \item{lib.loc}{A character vector of directory names of \R libraries.
    Defaults to all libraries currently known.}
    \item{verbose}{logical; if \code{TRUE}, the file name is reported.}
    \item{chmhelp}{logical (or \code{NULL}).  If \code{TRUE} the
    Compiled HTML version of the help will be shown in a help viewer.}
    \item{htmlhelp}{logical (or \code{NULL}).  If \code{TRUE}, the HTML
    version of the help will be shown in a browser.}
    \item{winhelp}{logical (or \code{NULL}).  If \code{TRUE}, a Windows
    \code{.hlp} file will be used if one is available.}
}
\description{
    These functions provide access to documentation.
    Documentation on a topic with name \code{name} (typically, an \R
    object or a data set) can be printed with either \code{help(name)} or
    \code{?name}.
    In the case of unary and binary operators and control-flow special
    forms, the name may need to be quoted.

    If \code{offline} is \code{TRUE}, hardcopy of the documentation is
    produced by running the LaTeX version of the help page through
    \code{latex} (note that LaTeX 2e is needed). You need to customize
    the file \file{R\_HOME/bin/helpPRINT.bat} which contains an example.  
    The appearance of the output can be customized through a file
    \file{Rhelp.cfg} somewhere in your LaTeX search path.
}
\note{
    The help files can be many small files. On some file systems it is
    desirable to save space, and the text files in the \file{help} directory
    of an installed package can be zipped up as a zip archive
    \file{Rhelp.zip}. Ensure the files \file{AnIndex} and
    \file{00Titles} remain un-zipped.  Similarly, all the files in the
    \file{latex} directory can be zipped to \file{Rhelp.zip}.
}
\seealso{
    \code{\link{help.start}()} which opens the HTML version of the \R
    Manual;
    \code{\link{library}()} for listing available packages and the
    user-level objects they contain;
    \code{\link{data}()} for listing available data sets;
    \code{\link{methods}()}.

    See \code{\link{prompt}()} to get a prototype for writing \code{help}
    pages of private packages.
}
\examples{
help()
help(help)      # the same

help(lapply)
?lapply         # the same

help("for")     # or ?"for", but the quotes are needed
?"+"

help(package = stepfun) # get help even when it's not present

data()          # list all available data sets
?women          # information about data set "women"

topi <- "women"
\dontrun{help(topi) ##--> Error: No documentation for `topi'}
}
\keyword{documentation}