NAME
r - Provides hash-bang (#!) capability for R (www.r-project.org)
SYNOPSIS
r [options] [-|file] [R arguments]
DESCRIPTION
Launches GNU R to execute the specified file containing R commands, or takes commands from stdin if ’-’ is used to denote stdin, using the specified options. This makes it suitable to create R scripts via the so-called shebang ’#!/’ line. The optional R arguments are stored in the R vector argv.
OPTIONS
-h, --help
Display a short help list.
--usage
Give a short usage message.
-V, --version
Show the version number.
-v, --vanilla
Pass the ’--vanilla’ option to R.
-t, --rtemp
Use a per-session temporary directory as R does.
-i, --interactive
Force ’interactive()’ to evaluate to TRUE, whereas the default is FALSE.
-q, --quick
Skip autoload (i.e. delayed assign) of default libraries.
-p, --verbose
Print the value of expressions to the console.
-l, --packages list
Load the R packages from the comma-separated ’list’.
-d, --datastdin
Evaluates ’X <- read.csv(file="stdin", stringsAsFactors=FALSE)’ to read a data set from stdin.
-L, --libpath dir
Add directory to library path via ’.libPaths(dir)’.
-e, --eval expr
Evaluate ’expr’ in R.
USAGE
r can be used in command-line ’pipes’ as well as in ’shebang’-style scripts.
EXAMPLES
Piping R commands:
echo ’cat(pi^2,"\n")’ | r
Equivalently, R commands can be given on the command-line:
r -e ’cat(pi^2, "\n")’
Alternatively, commands can be stored in a file, which in turn might use R command ’readLines’ to process stdin input:
$ cat
examples/fsizes.r
fsizes <- as.integer(readLines())
print(summary(fsizes))
stem(fsizes)
which can be evaluated by r with the following command:
ls -l /boot | awk ’!/^total/ {print $5}’ | r examples/fsizes.r
The script file may contain a "shebang" line:
$ cat
examples/install.r
#!/usr/bin/env r
# a simple example to install one or more packages
if (is.null(argv) | length(argv)<1) {
cat("Usage: installr.r pkg1 [pkg2 pkg3 ...]0)
q()
}
repos <- "http://cran.us.r-project.org";
lib.loc <- "/usr/local/lib/R/site-library"
install.packages(argv, lib.loc, repos,
dependencies=TRUE)
and if it is executable, it can be called as:
examples/install.r "TeachingDemos"
See the examples directory in the sources for more.
NOTE
The executable program is called r, but the project is called littler to avoid confusion with the real GNU R.
SEE ALSO
The GNU R language is documented extensively at the R website (http://www.r-project.org) and in several manuals available in html, info and pdf.
AUTHORS
Jeffrey Horner <jeff.horner [AT] vanderbilt.edu>. Dirk Eddelbuettel <edd [AT] debian.org>.