Earlier this week, Google hosted the Bay Area useR Group at our San Francisco office. Over 40 attendees showed up to hear Dylan Beaudette from UC Davis give a presentation about investigating soil genesis and geography with R (PDF). Dylan has been using R to study and visualize large amounts of ... [Read more...]

Last night, while working on something else that I want to finish, I ended up indulging in a bit of "yak shaving". I wondered how easy it would be to generate graphics in ggplot2 with rounded corners. I don't think that there is any nativ... [Read more...]

Another Sudoku-like puzzle from the weekend edition of Le Monde. The object it starts with is a 9×9 table where each entry is an integer and where neighbours take adjacent values. (Neighbours are defined as north, west, south and east of an entry.) The question is about whether or not it ... [Read more...]

Tiobe Software ranks the popularity of programming languages based on references in search engines. While the methodology might be debated in terms of the absolute rankings it produces, it is quite interesting to see how the rankings fluctuate over time: Tiobe has produced a monthly report of rankings based on ... [Read more...]

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Following my post on citations in academic journals, I wanted to go one step further in the understanding of the dynamic of citations. So here, the dataset looks like that: for each article, we have the name of the journal, the year of publicatio... [Read more...]

An ‘Og reader. Emmanuel Charpentier, sent me the following email about model choice: I read with great interest your critique of Peter Congdon’s 2006 paper (CSDA, 50(2):346-357) proposing a method of estimation of posterior model probabilities based on improper distributions for parameters not present in the model inder examination, as ... [Read more...]

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It's great to see the growth in R user groups around the world, and now there are three new ones in western Europe: In Amsterdam, a new R user group has just formed, called amst-R-dam. They are just scheduling their first meeting now (vote here for a date) which will ... [Read more...]

I am in Montpellier today for a general meeting of our EMILE ANR grant bi-yearly meeting, discussing ABC model choice and new applications of simulation methods in population genetics, including an upgrade of DIYABC into the 2.0 version. (The above is a picture comparing “true” Bayes factors with ABC versions, commented ... [Read more...]

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In Chapter 5 of Using R for Introductory Statistics we get a brief introduction to probability and, as part of that, a few common probability distributions. Specifically, the normal, binomial, exponential and lognormal distributions make an appearance.... [Read more...]

Admittedly I am not the best R coder, and I certainly have a lot to learn, but the code at the link below should provide you with an example of how easy it is to create a very (repeat: very) basic web crawler in R.  If you wanted to do ... [Read more...]

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R is a fantastic bit of software which I have been using on and off for a number of years since I gave up on SAS due to their (free for academics) annoying licenses and limited support for the things I wanted to do – R is infinitely flexible and totally ... [Read more...]

There are a couple of options in R, if you want to utilize multiple cores on your machine. These days my favorite is doMC package, which depends on foreach and multicore packages.in the section below squareroot for each number is calculated in parallel... [Read more...]

C/python style option parsing now available in R with "optparse" package. Check the documentation here and see below to see how it worksuser@node002 scripts $ Rscript filter.transcripts.by.ncRNA.R -husage:  usage: filter.transcripts.by.ncRNA.R [op... [Read more...]

In R, you can treat tables (or data.frames as they are called in R) as SQL tables. That means you can query them as you would query a database with SQL commands. This is particularly useful 1) if you know SQL, hahah:)  2) if you have large tabl... [Read more...]

If you're planning to go to R/Finance 2011[*] in Chicago (and if you're doing quantitative finance with R, you definitely should), time is running out to submit your abstract for contributed talks. The best part of R/Finance is learning about all the interesting ways R is used to analyze ... [Read more...]