How To Install a R Package Locally and Load it Easily?

source: http://cmdlinetips.com/2012/05/how-to-install-a-r-package-locally-and-load-it-easily/

R has been one of the popular languages for anything to do with large amount of data. There are loads of useful packages that let you get started immediately in using a wide realm of statistical/computational tools. Installing an R package is easy. Typically, R Packages can be downloaded as “tar.gz” file for Mac OS X from CRAN sources. The command to install a R package to all users in your machine is

R CMD INSTALL -l myRPackage.tar.gz

Local Installation of R Packages

Sometimes you might want to install a R package locally, either because you may not have root access to install a package globally or you may just want to try out a new package before installing globally. Here is how to install a R package locally from the terminal.

To install a R package locally, specify the local directory where you want to install by using the “-l” option in the “R CMD INSTALL” command. For example, to install the R package in the local directory “/usr/me/localR/library”, use the “R CMD INSTALL” as follows.

R CMD INSTALL -l /usr/me/localR/library myRPackage.tar.gz

How to Load a Locally Installed R Package and Use it?

Installing R Packages at a local directory is only a first step. There are a few ways to load the locally installed R packages and use them. One option is to specify the local path to the R package while loading the library. The R command to load a general package is

library("RPackage")

To load a locally installed R package, use the library command with parameter lib.loc as

library("myRPackage", lib.loc="/usr/me/local/R/library")

Another option is to instruct your .bashrc file to add the the path to local R library. This option lets you load the package without specifying the local every time. To enable this add the following to your .bashrc

if [ -n $R_LIBS ]; then   export R_LIBS=/usr/me/local/R/library:$R_LIBS else   export R_LIBS=/usr/me/local/R/library fi

After adding you can check if the local R package directory in the R library path using the R command “.libPaths()“. Typing “.libPaths()” in R, will show all the R library paths. If your local R library path is not added properly, you will only see one general path to R library, like
“/opt/R/2.11.1/lib64/R/library”.