I can't believe it's been two months since I last posted... wow, time has a way of slipping through my fingers. Here's a short list of some upcoming posts: An introduction to LSPM -- a new R package that implements Ralph Vince's leverage space po...

The R Function of the Day series will focus on describing in plain language how certain R functions work, focusing on simple examples that you can apply to gain insight into your own data. Today, I will discuss the table function. What situation is table useful in? The table function is a very basic, but

Edit: This post originally appeared on my Wordpress blog on September 21, 2009. I present it here in its original form. The R Function of the Day series will focus on describing in plain language how certain R functions work, focusing on si...

One of the nicer things about many statistics packages is the extremely granular control you get over your graphical output. But I lack the patience to set dozens of command line flags in R, and I'd rather not power the computer by pumping the mouse trying to set all the clicky-box options in Stata's graphics editor. I want something...

Edit: This post originally appeared on my Wordpress blog on September 20, 2009. I present it here in its original form. The R Function of the Day series will focus on describing in plain language how certain R functions work, focusing on sim...

Edit: This post originally appeared on my Wordpress blog on September 20, 2009. I present it here in its original form. John Tukey's preface to Exploratory Data Analysis begins with a useful rule, "It is important to understand what you can...

The R Function of the Day series will focus on describing in plain language how certain R functions work, focusing on simple examples that you can apply to gain insight into your own data. Today, I will discuss the tapply function. What situation is tapply useful in? In statistics, one of the most basic activities

Version 0.1.0 of RInside, my C++ wrapper classes which facilitate embedding R into your own C++ application, has been released and is now an official CRAN package. This release improves on the build process and should work on any sane Unix-alike o...

Version 0.1.0 of RInside, my C++ wrapper classes which facilitate embedding R into your own C++ application, has been released and is now an official CRAN package. This release improves on the build process and should work on any sane Unix-alike opera...

Version 0.1.0 of RInside, my C++ wrapper classes which facilitate embedding R into your own C++ application, has been released and is now an official CRAN package. This release improves on the build process and should work on any sane Unix-alike o...

This is tremendously cool. A nice intuitive web-based interface for the lme4 package in R (and you neither need to know R or understand the intricacies of the lme4 package) that gives you pdf output and plots. If you just want to play around and not worry about coding things up, it’s a great little

This came up recently on StackOverflow. One of the answers was particularly helpful and I thought it might be worth mentioning here. The idea presented there is to break the code into four files, all stored in your project directory. These four files are to be processed in the following order. load.R This file includes

This came up recently on StackOverflow. One of the answers was particularly helpful and I plan to adopt this for my future work. In fact, it is close to what I already do, but is a little more structured. The idea is to break the code into four files, ...

The Law of Large Numbers concerns the stability of the mean, as sample sizes increase. This is an important topic in mathematical statistics. The convergence (or lack thereof, for certain distributions) can easily be visualized in SAS and R (see also Horton, Qian and Brown, 2004).Assume that X1, X2, ..., Xn are independent and identically distributed realizations...

At this week's R clinic Frank Harrell will unveil the new rms (Regression Modeling Strategies) package that is a replacement for the R Design package. He will demonstrate the differences with Design, especially related to enhanced graphics for displaying effects in regression models. Frank will also discuss the implementation of quantile regression in rms. The rms package website has...

Any R user no matter what level of experience has had trouble finding the package or the function to do what you want to do and then figuring out how to use it. The sos package in R just made that a lot easier. First, fire up R, then install the sos package (don't omit the quotes): install.packages("sos") It'll ask you to...

Today it was once again time for the Chicago Half Marathon (which I have now been running in 2003, 2004, 2005, 2006, 2007 and 2008). Conditions were much much better than last year's very heavy rainfall---we were once again treated to a sunny and clear Chicago sky. It was however a little on the humid side and got...

Suppose you want a function to fit a neural network. What’s the best way to find it? Here are three steps that help to find the elusive function relatively quickly. First, use help.search("neural") or the shorthand ??neural. This will search the help files of installed packages for the word “neural”. Actually, fuzzy matching is used