## R

## » Back from the BoRdeaux conference • Jul 4, 02:24 PM

Here is a quick wrap up of the BoRdeaux conference.

## » Easy creation of videos with R • Apr 15, 09:00 AM

While preparing a talk due in three days or so, I thought it would be good to show some live demonstration of regularization techniques in regression with ggplot2.

## » Easier literate programming with R • Apr 2, 07:22 PM

I have been using Sweave over the past 5 or 6 years to process my R documents, and I have been quite happy with this program. However, with the recent release of knitr (already adopted on UCLA Stat Computing and on Vanderbilt Biostatistics Wiki) and all of its nice enhancements, I really need to get more familiar with it.

## » Playing with TwitteR • Jun 25, 08:02 AM

Some months ago, I played with Un*x command-line tools to parse my tweets fetched from BackupMyTweets. Here is a more elegant to do so with R.

## » Design of Experiments in R • May 28, 11:05 AM

When I started writing my companion textbook for Montgomery's *Design and Analysis of Experiments*, there was not so much dedicated package available on CRAN.

## » Recursive feature elimination coupled to SVM in R • May 22, 07:29 PM

I recently wondered whether it is possible to apply Recursive Feature Selection with SVM in R.

## » Using bootstrap in cluster analysis • May 22, 10:13 AM

Lastly, I came again across a nice poster from Tom Nichols that was presented at the OHBM2010 conference. This was about Finding Distinct Genetic Factors that Influence Cortical Thickness, and the clustering method that was used was interesting.

## » Pretty printing statistical distribution tables • Apr 30, 06:05 PM

Before using statistical software, we were teached to use standard tables for finding the quantile of a standard normal or a Student's t distribution, given a type 1 risk. Here is a way to quickly print them on a PDF file using R and L^{a}T_{e}X.

## » Computing intraclass correlation with R • Apr 29, 04:04 PM

I always found Dave Garson's tutorial on Reliability Analysis very interesting. However, all illustrations are with SPSS. Here is a friendly R version of some of these notes, especially for computing intraclass correlation.

## » Fitting Rasch model with R lme4 • Mar 12, 05:17 PM

The last issue of the *Journal of
Statistical Software* features an article on
The Estimation of Item Response Models with the lmer Function from the lme4 Package in R,
by De Boeck and coll. As the title suggests, this article is about
fitting IRT models with a mixed-effects model approach.