Here is an interesting question from Tomàs that echoes a lot of related emails: I’m turning to you for advice. I’m facing problem  where parameter space is bounded, e.g. all parameters have to be positive. If in MCMC as proposal distribution I use normal distribution, then ... [Read more...]

The R Project would not exist without the contributions of the R Core Group, the 21 volunteer statisticians and computer scientists from around the world who have donated their time and expertise to create the R langauge, its core packages, and manage its regular release and binary distribution process via the ... [Read more...]

I have something a fondness for ridiculous variable names, so it’s useful to be able to check whether my latest concoction is legitimate. More so if it is automatically generated. Not having an is_valid_variable_name function is one of those odd omissions from R, and the assign ... [Read more...]

Kaggle has released a new data-mining challenge: use data from 10 years of Wikipedia edits in order to predict future edit rates. The dataset has been anonymized in order to obscure editor identity and article identity, simultaneously adding focus to the challenge and robbing the dataset of considerable richness. I have ... [Read more...]

If you're looking for connections with expertise in R programming, the new Skills and Expertise feature on LinkedIn makes it easy. Just visit the R Skills page for a list of R practitioners on LinkedIn. You can also add "R" to your own list of skills from the same page. ... [Read more...]

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Following a series of pre-releases, Armadillo version 2.0.0 was announced by Conrad Sanderson earlier in the week. As it happens, it contained another minor build regression so version 2.0.1 followed the next day. We created versions 0.2.24 and 0.2... [Read more...]

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The R Core team announced today that the next update to R, version 2.13.1, will be released on July 8. Core team member Peter Dalgaard noted: The 2.13.0 release has been quite solid, but some people expect an x.y.1 to roll out on larger installations for the next academic year. Of course, ... [Read more...]

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Here’s a bit of code used to produce one of the figures in my recent paper dealing with modeling rocky intertidal snail body temperatures. This was my first foray into ggplot2, and it only involved a few hours of head-scratching. The plot is a co... [Read more...]

SoilWeb is an interactive, multifaceted interface to USDA-NCSS soil survey information. Our SoilWeb application for Google Earth streams soil map units and point data as you navigate across the lower '48 states. Currently, our system imposes a 30,000 ... [Read more...]

The blog Heuristically Andrew puts Revolution R through its paces by running some benchmarks versus open-source R for data mining applications. The benchmarks set out to answer the following question: I recently upgraded my notebook (where I often use R for data mining) and was faced with two questions: for ... [Read more...]

Yesterday the Princeton machine learning reading group went through a paper by Tukey on “Some graphic and semigraphic displays”. One issue we talked about at length was Tukey’s idiosyncratic approach to visualizing periodic data in a circular format to emphasize the connections between the “start” and the “end” of ... [Read more...]

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