R Statistical Language Introduction/Tutorial/Demonstration Patrick R. McMullen Wake Forest University Schools of Business mcmullpr@wfu.edu

R History Initially developed by Ross Ihaka and Robert Gentleman at the University of Aukland, New Zealand The software was developed to be a free version of the already existing S Statistics Language The name “R” has dual-meaning: it is a reference to the “S” software, and a reference to the first names of the two developers

R History R is part of the GNU Project, a free-software collaborative initiative Part of R’s mission is to keep the software evolving to meet the needs of its continuously-growing body of users Regular users of R can make modifications to the software to customize their needs R has a governing board that decides which of these modifications should be distributed with the R installation

R History R was initially used mainly in New Zealand, Australia and Western Europe Since then, its use has become more international, including the US and Canada Its market share in statistical computing software has rapidly grown Manufacturers of competing products, such as SAS, have offset their reduced market share with consulting services Universities are huge proponents of R

R Packages When a user creates some new feature that adds to the capability of R, they have created a “package” The user can send the “package” to the governing body of R, and the governing body can include this package in their next update of the free software This type of process is a trademark feature of what is called the “Open Source” movement R is updated about once per year, but there is no fixed pattern to their updates. The current version of R is 2.15, although I used 2.12.1

R Packages Presently, there are more than 3,000 packages available in the most current version of R These packages run the gamut from the very trivial to the very complex (structural equation modeling, for example) The packages used to perform basic statistics and graphics are included in the basic installation of R Other packages that perform more specialized things must be downloaded, installed and loaded This process is quite straightforward

R Installation R can be installed via my web-site: http://www.joydivisionman.com/R/ Choose the “R Installation Link” R can be installed via their web-site: http://www.r-project.org

R Installation After basic installation, packages can be installed as needed

R Usage Interactive Batch Files When a user has communication with R on an as-needed basis Batch Files When a user submits a file containing multiple commands Some combination of interactive and batch file usage Batch files are frequently used to load data sets, and interactive commands are used to manipulate and analyze data

Using R Interactively Type commands at the prompt

Using R via Batch Files Load a text file with the “R” extension

R Packages That I Use stats – package that provides basic statistical functionality (automatically installed/loaded) graphics – package that permits basic graphics (not automatically installed/loaded) MASS – multivariate statistical functionality (not automatically installed/loaded)

R Packages That I Use scatterplot3d – package that enables 3-dimensional graphics (not automatically installed/loaded) sem – package that provides functionality for Structural Equation Modeling (not automatically installed/loaded)

R Tutorial/Demonstration What was it that Jackie Gleason said ???