.TH R 1
.SH NAME
R \- a language for data analysis and graphics
.SH SYNOPSIS
.B R
[
.I options
]
[
<
.I infile
]
[
> 
.I outfile
]
.SH DESCRIPTION
R is a language which bears a passing resemblance to the S language
developed at AT&T Bell Laboratories.
It provides support for a variety of statistical and graphical analyses.
R is a true computer language which contains a number
of control-flow constructions for iteration and alternation.
It allows users to add additional functionality by defining
new functions.
.LP
On platforms which support the
.BR dlopen (3)
interface, Fortran and C code can be linked and called at run time.
.LP
On systems which have the GNU
.BR readline (3)
library, R will maintain a command history,
so that commands can be recalled, edited and
re-executed.
.SH OPTIONS
The following options allow users to change the amount of memory
which R uses to store its internal data sets.
If possible these sizes should be set so that R does not use
more than the amount of physical memory available on the machine
where the program is executing.
This will minimize paging and ensure that execution
is as efficient as possible.
.TP
\fB\-\-vsize\fP \fIn\fP
Use a vector heap of size \fIn\fP megabytes (the default is 2).
.TP
\fB\-\-nsize\fP \fIn\fP
The number of \fIcons cells\fP (each occupying 16 bytes)
which R is to use (the default is 200000).
.LP
The following options relate to the saving and restoring of a user's
data sets and functions at startup and termination.
.TP
.B \-\-no\-save
Do not save the data sets at the end of the R session.
This is only effective when R is used non-interactively.
.TP
.B \-\-save
Do save data sets.
.TP
.B \-\-no\-restore
Do not restore any previously saved datasets (an \fIimage\fP).
.TP
.B \-\-restore
Do restore previously saved datasets (this is the default).
.LP
The following options are present to support the use of
R from other programs.  In particular, the
.B \-\-no\-readline
option exists so that R can be run under
.IR emacs (1)
and
.IR xemacs (1)
using ESS.
.TP
.B \-\-no\-readline
Turn off the use of the
.IR readline (3)
command line editing.
.TP
.B \-\-quiet\fR,\fP \-\-silent
Do not print out the initial copyright and welcome messages.
.TP
.B \-\-slave
Make R run as quietly as possible.  This option is intended to support
programs which use R to compute results for them.
.LP
The following options are available so that the R developers can carry
debugging.
.TP
.B \-\-debugger \fIname\fP
Run R under the control of the debugger named
.IR "name".
May be abbreviated to \fB-d\fP.
.TP
.B \-\-verbose
Print more information about progress.
.LP
Startup processing (see also below) is controlled by the following
options.
.TP
.B \-\-no\-site\-file
Do not load the site-wide startup profile.
.TP
.B \-\-no\-init\-file
Do not load the user's \fB.Rprofile\fR.
.LP
Finally, the following options produce informative output.
.TP
.B \-\-help
Print some useful usage information and exit.
May be abbreviated to \fB-h\fP.
.TP
.B \-\-version
Print the version number and exit.
.SH STARTUP PROCESSING
When R is invoked, it first searches for the site-wide startup profile
unless
.B \-\-no\-site\-file
was given.  The name of this file is taken from the value of the
.B R_PROFILE
environment variable.  If that variable is unset, the default is
\fIR_HOME/etc/Rprofile\fP.

Unless
.B \-\-no\-init\-file
was given, R then searches for the files
.B .Rprofile
and
.B ~/.Rprofile
(in that order) and executes any statements in the first of these files
to be found.

Finally, if a user has defined a function called
.BR \&.First ,
it will be invoked.
After these steps, an read-eval-print loop is run
for user input.
.SH FILES
.PD 0
.TP 12
\&.RData
saved data sets.
.TP
\&.Rhistory
saved command history.
.TP
\&.Rprofile
current directory startup file.
.TP
\&~/.Rprofile
home directory startup file.
.PD
.SH SEE ALSO
.BR S (1) ,
.BR Splus (1),
.BR readline (3).
.SH BUGS
R is very close to S in both syntax and semantics, but is not identical.
Whether this is a bug or feature is an open question.