Installation

• For Mac OS-X, go here, and click R-2.6.1.dmg. Double click the downloaded disk image, and double click R.mpkg, and follow the instructions.
• For Windows, go here, and click R-2.6.1-win32.exe, and follow the direction of installer. I don't know much about Windows, but it was pretty simple.
• Linux users probably know how to install R.

Packages

• R is modular, and you can enhance the functionality of R by using Contributed packages in CRAN . To install these extra packages, you can see the Section 6 of R Installation and Administration .

• One way of installing packages are using install.packages() inside of R.

  > install.packages("ape", dependencies = TRUE)
  

  This will automatically download and install the package ``ape''.

• To ``use'' the package,

  > library("nlme")
  

  Note that package ``nlme'' is included in the default installation, so you did not need to install it before you use it.