Pivot Tables are a useful way of aggregating data into the format that you’re after. In this example, I’m going to be using R to pivot some data and calculate medians for me. This is useful because Excel can calculate medians (the =MEDIAN(values)) function, but what it ... [Read more...]

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Thought some of the R-Blogger readers would be interested in the position linked below. If you're a baseball fan and like working in R, this is a fun company that seems to be getting more and more press. Recently, it was featured in Sports Illustrate... [Read more...]

In health economics it is common to use agent-based simulations for exploring epidemiological models, prevention policies, and clinical interventions, among other things. In C++ I enjoy using object-oriented design to build these agent-based models. It feels so natural. In R, … Continue reading → [Read more...]

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Introduction Suppose you see two drunks (i.e., two random walks) wandering around. The drunks don’t know each other (they’re independent), so there’s no meaningful relationship between their paths. But suppose instead you have a drunk walking with her dog. This … Continue reading → [Read more...]

Corporate IT networks are a pain for programmers. Ideally, when programming, you want the freedom to download, install and run any software that you want. Unfortunately, in the interests of security, many programmers find themselves a little restricted at the office. (I’m sure that many network admins will protest ... [Read more...]

If you missed Wednesday's webinar on Deploying Predictive Analytics with Revolution R, PMML and ADAPA, the presentation slides and the replay (in WMV, reg. req'd) format are now available for download. Here are some additional references, from the closing slide: How Revolution R and ADAPA work together The PMML Package ... [Read more...]

With Tax Day fast approaching here in the US, there's been a lot of discussion about tax policy and in particular the tax rates paid by the highest income earners. Like in many countries, here the income tax system is bracketed: Tax Bracket Single Married Filing Jointly 10% Bracket $0 – $8,375 $0 – $16,750 15% Bracket $8,375 – $34,000 $16,750 – $68,000 25% Bracket $34,000 – $82,400 $68,000 – $137,300 28% ... [Read more...]

I sometimes feel like this picture: alone, left with just my thoughts and a little light to illuminate my work. For my daughter pictured above on the stool, her work is a pen and ink drawing. For me, it’s a finished piece of software to share with t... [Read more...]

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Some of you may hear that the new release of R 2.13.0 is out, with some Windows-specific changes to R 2.13.0:file.exists() and unlink() have more support for files __ 2GB;A few more file operations will now work with __2GB files.which could help us to relieve the worry of handling ... [Read more...]

The development team has spent the past six months creating the best possible experience for RTextTools users. A few months into development, we heard about a new IDE called RStudio, which has one of the cleanest interfaces to R we've seen. It integrates many R tools (graphing, file management, workspace ... [Read more...]

Background – time to upgrade to R 2.13.0 The news of the new release of R 2.13.0 is out, and the R blogosphere is buzzing. Bloggers posting excitedly about the new R compiler package that brings with it the hope to speed up our R code with up to 4 times improvement. So it ... [Read more...]

If you: use Linux have just upgraded your R installation from 2.12 to 2.13 installed some/all of your packages in your home area (e.g. ~/R/i486-pc-linux-gnu-library/2.12) and… …are wondering why R can’t see them any more just do this: # at a shell prompt cp ~/R/i486-pc-linux-gnu-library/2.12 ~/R/... [Read more...]

This morning I tried to completely update my R installation. I first dumped a list of all the packages I have on my system using the installed.packages() function. Then I installed R 2.13.0 using the OS X disk image. And finally I reinstalled all of my packages from scratch. Unfortunately, ... [Read more...]

For those who are excited about the new 2.13.0 release of R (particularly the compiler package) but are grumbling about having to remember what packages they have and re-install them, see this great advice or this piece on upgrading in osx for how to a... [Read more...]

gRain is an R package for "probability propagation in graphical independence networks, also known as probabilistic expert systems (which includes Bayesian networks as a special case)". This package caught my attention because some genetic models can b... [Read more...]

In case you missed them, here are some articles from February of particular interest to R users. The doSMP package, which enables parallel processing for R on multiprocessor machines, is now available on CRAN. The Offensive Politics blog provided R code used to make a map of precinct returns in ... [Read more...]