Steve McNally of the Forbes Mean Business blog says R is a name you need to know for 2011. He cites some great examples of R in action: Facebook has used R to figure out that “just two data points are significantly predictive of whether a user remains on Facebook: (i) ... [Read more...]

Prof. Chris Fonnesbeck briefly introduces Bayesian inference, then discusses how to estimate Bayesian models with Markov Chain Monte Carlo using PyMC. PyMC is the premier Python package for doing MCMC estimation, and Prof. Fonnesbeck is one of the pac... [Read more...]

At last... I have been suffering with XEmacs displaying odd characters instead of the quotation marks that are used in R help files. This was driving me up the wall because it makes the files (and R output in general) very hard to read; however, I fina... [Read more...]

As part of my on-going research simulating network structure using graph motifs I have been collecting novel data sets to test and benchmark the method. Since I am a political scientist studying conflict, it was suggested to me to collect a co-authorship network within this sub-discipline. Such a network is ... [Read more...]

Here and there, I mentioned two codes to generated quasiPoisson random variables. And in both of them, the negative binomial approximation seems to be wrong. Recall that the negative binomial distribution is where and in R, a negative binomial di... [Read more...]

'Indeed, I am moving on: my new project is about methods on how to domesticate the unknown, exploit randomness, figure out how to live in a world we don't understand very well. While most human thought (particularly since the enlightenment) has focused us on how to turn knowledge into decisions, ... [Read more...]

I’ve had a few emails lately about forecast evaluation and estimation criteria. Here is one I received today, along with some comments. I have a rather simple question regarding the use of MSE as opposed to MAD and MAPE. If the parameters of a time series model are estimated ... [Read more...]

Following the posting on arXiv of the Statistical Science paper of Carvalho et al., and the publication by the same authors in Bayesian Analysis of Particle Learning for general mixtures I noticed on Hedibert Lopes’ website his rejoinder to the discussion of his Valencia 9 paper has been posted. Since the ... [Read more...]

Are there any R packages to solve Vehicle Routing Problem (VRP)?I looked around but could not find any... Any leads?VRP is a classic combinatorial optimization challenge and has been an active area of research for operations research gurus fo... [Read more...]

The co-creator of R, University of Auckland Associate Professor of Statistics Dr. Ross Ihaka, was yesterday awarded the Catalyst Lifetime Achievement in Open Source Award at the 2010 New Zealand Open Source Awards. From the announcement: Dr. Ihaka is one of the originators of the world-renown ‘R’ programming language and software ... [Read more...]

The 27 base and recommended libraries of the standard R 2.12 distribution together contain 3556 functions (you can check using the code posted after the jump). Many of the functions are commonly used: c, data.frame, rnorm, lm. But some of those functions, while being extremely useful, may be less well known to ... [Read more...]

The latest local R user group to form is located in Houston, Texas. The first meeting of the Houston R Users Group is tonight at Rice University (in conjunction with the Houston chapter of the ASA). R hackr (typo intended!) Hadley Wickham will be giving a presentation on writing R ... [Read more...]

There have been some very good visualizations of the Wikileaks data so I decided to create one of the drug war in Mexico The above map was made using data collected by Walter McKay, mainly from El Universal and El Diario reports. The data is stored as a Google Map ... [Read more...]

The game ARORA (A random or real array) is a website that gives you two time series at a time. Your job is to guess which series is real market data and which is permuted data.  It’s fun — try it. With some practice you will probably be able to ... [Read more...]

José Bernardo forwaded this announcement that sounds quite attractive (conditional upon living in a remote part of Texas!) Senior Faculty Position in Computational Statistics At Texas A&M University As part of a recognition of the increasing importance in the modeling and computational sciences, the Department of Statistics at Texas ... [Read more...]

Last month, the newest member of Revolution's engineering team, Saptarshi Guha, gave a presentation at Hadoop World 2010 on using R and Hadoop to analyze 1.3 billion voice-over-IP packets to identify calls and measure call quality. Saptarshi, of course, is the author of RHIPE, which lets R programmers write map-reduce algorithms in ... [Read more...]

The fine bloggers (and R experts) at the Dataists have volunteered to answer questions about data analysis on Reddit: A few months ago, a group of likeminded folks in New York and the San Francisco Bay area decided it was time to start a blog about data, and we can ... [Read more...]

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New York’s annual marathon took place yesterday. Watching a bit of it on television with my friends, I was struck by the much earlier starting time for women than men. Specifically, professional women started running yesterday at 9:10 AM, while professional men start running at 9:40 AM. (This information comes from ... [Read more...]

In the final days of October, my beginner's guide to R was released. The book's official title is Statistical Analysis with R and it can be found on the Packt Publishing website. The primary focus of Statistical Analysis with R is helping new users bec... [Read more...]