StATS: Two nice R libraries (October 14, 2005).
I found a couple of nice libraries in R available from CRAN (Comprehensive R Achive Network). The first, vcd, was recommended by a regular contributor to the epidemio-l list. This library provides visualization techniques with special emphasis on categorical data. There is a nice function to draw a series of odds ratios and confidence intervals, for example, and very simple code to produce a mosaic plot. A more thorough description of vcd is available at
According to the description, the functions in vcd were inspired by the book
which I do not have in my library, but which sounds like a very interesting book.
I found the second library, epitools, when I went searching on the web for resources to calculate an exact confidence interval for a Poisson rate. In addition to the exact Poisson intervals, the package can perform age standardization, draw epidemic curves, and has a variety of useful utility functions and interesting data sets. The description of epitools is available at
and the authors maintain a site for this library and other free software at
This page was written by Steve Simon while working at Children's Mercy Hospital. Although I do not hold the copyright for this material, I am reproducing it here as a service, as it is no longer available on the Children's Mercy Hospital website. Need more information? I have a page with general help resources. You can also browse for pages similar to this one at Category: R software.