External Packages

## 17  External Packages

R comes complete with its base libraries and often some recommended'' packages. You can extend your version of R by installing additional packages. A package is a collection of functions and data sets that are packaged'' up for easy installation. There are several (over 150) packages available from http://cran.r-project.org/.

If you want to add a new package to your system, the process is very easy. On Unix, you simply issue a command such
   R CMD INSTALL package_name.tgz

If you have the proper authority, that should be it. Painless.

On Windows you can do the same
   Rcmd INSTALL package_name.zip

but this likely won't work as Rcmd won't be on your path, etc. You are better off using your mouse and the menus available in the GUI version. Look for the install packages menu item and select the package you wish to install.

The installation of a package may require compilation of some C or Fortran code. usually, a Windows machine does not have such a compiler, so authors typically provide a pre-compiled package in zip format.

For more details, please consult the R Installation and Administrator'' manual.