Get Everything Set Up I’m going to assume that you have access to a machine that will run JAGS. If you don’t, then you should be able to use WinBUGS, which is very easy to get set up. Unfortunately, the details of what follows may not help you ... [Read more...]

project outcomes —————- radx: forward automatic differentiation in R tada: templated automatic differentiation in C++ development summary ——————- During the summer of 2010, under the Google Summer of Code program, I was assigned the project of implementing an engine for Automatic Differentiation in R. The implementation involved building a fully functional ... [Read more...]

For Part I, Parallelism in R, click here. Tuesday night I again had the opportunity to present on high performance computing in R, at the Los Angeles R Users’ Group. This was the second part of a two part series called “Taking R to the Limit: High Performance Computing in ... [Read more...]

The devastating heatwave in Russia now seems to be over, but not before killing thousands, causing extensive wildfires, and destroying crops. But how severe was this heatwave, compared to past summers? Physicist and climate scientist Joe Wheatley looks at the record of temperature and rainfall in Russia over the last 60 ... [Read more...]

The other day, an article was published in PLoS One describing a newly developed JavaScript library to visualise phylogenetic trees online: jsPhyloSVG. It's pretty nifty, and there's some pretty cool functionality that you can build into the trees. It's all based on the PhyloXML standard for describing phylogenetic trees and ... [Read more...]

As I noted here, enclosing sub-expressions in parentheses is slower in R than enclosing them in curly brackets. I now know why, and I’ve modified R to reduce (but not eliminate) the slowness of parentheses. The modification speeds up many other operations in R as well, for an average ... [Read more...]

At any R Q&A site, you’ll frequently see an exchange like this one: Q: How can I use a loop to [...insert task here...] ? A: Don’t. Use one of the apply functions. So, what are these wondrous apply functions and how do they work? I think the ... [Read more...]

[This article was first published on Rmetrics blogs, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here) Want to share your [Read more...]

Last year there were over 2,600 murders in Ciudad Juarez, and if the more than 1,800 murders so far this year are any indications, there will be even more murders in 2010. Ciudad Juarez is a scary place, but it wasn't always that way... I learned from Noel Maurer's Blog that Ciudad Juarez ... [Read more...]

“How can I integrate PHP and R?” I know I’m not the only one who’s asked this question. After all, with great content management systems like Drupal, it would very cool to be able to drop an R module into some PHP code and instantly have a web ... [Read more...]

New local R user groups keep on popping up on a regular basis, which is great to see. The latest one is deep in SAS territory: it's the Raleigh-Durham-Chapel Hill R Users Group in They don't have any meetings scheduled just yet (but when they do their gracious meetup hosts ... [Read more...]

Hic sunt dracones used to be placed on maps, as a way to denote a dangerous or otherwise unexplored territory. We might as well write it all over R-related material used in introductory classes, because students seems to be really (…)Read the rest of this entry » [Read more...]

One of the R language's most powerful features is its ability to deal with random distributions: not just generating random numbers from various distributions (based on a very powerful pseudo-random number generator), but also calculating densities, probabilities, and quintiles. John Cook provides a handy reference chart listing all of the ... [Read more...]

I found time and read Gelman and Hill’s “Data Analysis Using Regression and Multilevel / Hierarchical Models“…Now, please do yourself a favour and get it (of course the paperback version ). Even for experienced or intermediate (myself) this will be a treat for your eyes and neurons. PS : (Confession) I ... [Read more...]

Neil Kodner wrote a great post this morning about yesterday’s Twifficiency scores outbreak. He grabbed all the auto-tweeted scores he could find and plotted their distribution. I was struck by the asymmetry of the resulting distribution, which you can see below: Thankfully, Neil handed me the raw data for ... [Read more...]

By popular demand (!), my state-by-state pendulum (pendula?) for 2010 is up (big PDF), just in time for the election.  550px wide JPG version is inline, below. This follows the same formatting I used in the 2007 edition. We start with the 2PP ALP vote shares recorded at the last election (incorporating changes ... [Read more...]

Ed Burnette makes a point that hits home, with regard to software patents, and how engineers and programmers of modern companies are now being asked to write them: Unfortunately, the joke is on all of us. It’s on our economy, as we let patents choke down innovation and increase ... [Read more...]

[Read more...]

Introduction This week I decided to start unit testing my R code, so I taught myself the bare minimum about the RUnit and testthat packages to be able to use them. Here’s what I found necessary to get started writing tests with both packages. RUnit Basic Example I’m ... [Read more...]

Visualisation of Activity in Afghanistan using the Wikileaks data from Mike Dewar on Vimeo. The latest visualization of the WikiLeaks data compiled by our group is an animation of the intensity of report observations in Afghanistan over the six year period in the WikiLeaks data. Team member Mike Dewar did ... [Read more...]