American Statistical Association New York City Metropolitan Area Chapter Chapter Lecture October 28, 2008

The R project www.r-project.org bills itself as "a free software environment for statistical computing and graphics." The word free refers to the open source nature of R, which is a large reason for R's increased usage. However, more importantly, the "software environment" that R provides allows its users the ability to more easily customize R to their specific needs than other software packages such as SPSS.

This presentation will be an overview with examples of how one programs in R starting with defining functions in R, discussing flow control in R and vectorization. We will end on the important concept of generic functions (or methods), as implemented in S3 and S4, which help tame R for its users.