The registration for R/Finance 2011--which will take place April 29 and 30 in Chicago--is NOW OPEN!Building on the success of the two previous conferences in 2009 and 2010, we are expecting more than 250 attendees from around the world representing bot... [Read more...]

Last month, Amanda Cox from The New York Times Graphic Department gave a great talk to the NYC R Statistical Programming Meetup. I’ve just got around to uploading the video, which has been broken into a part one and part two. You can also view the videos embedded after ... [Read more...]

Those in the political science discipline probably remember their first encounter with poliscijobrumors.com. For those outside, you have probably never heard of this particular message board, and you would have no reason to. As the URL suggests, the board specializes in rumor, gossip, back-bitting, mudslinging, and the occasional lucid ... [Read more...]

As announced yesterday by the R Core Team, the next major update to R will be released on April 13. R 2.13.0 is the next major release of R, which gets major updates approximately every six months. This also indicates that R 2.12.2 is the last patch level of the R 2.12 series, and ... [Read more...]

As demonstrated in the preceding ANOVA tutorials, data organization is central to conducting ANOVA in R. In standard ANOVA, we used the tapply() function to generate a table for a single summary function. In repeated measures ANOVA, we used separate da... [Read more...]

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I describe a kernel density approach to outlier detection on small datasets. In particular, my model is the set of prices for a given item that can be found online. Introduction Suppose you’re searching online for the cheapest place to … Continue reading → [Read more...]

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Lots of people know that the Riemann Hypothesis has something to do with prime numbers, but most introductions fail to say what or why. I’ll try to give one angle of explanation. Layman’s Terms Suppose you have a bunch of friends, each with an instrument that plays at ... [Read more...]

Suppose you’re very indecisive, so whenever you want to watch a movie, you ask your friend Willow if she thinks you’ll like it. In order to answer, Willow first needs to figure out what movies you like, so you give her a bunch of movies and tell her ... [Read more...]

(Way back when, I went through all the Netflix prize papers. I’m now (very slowly) trying to clean up my notes and put them online. Eventually, I hope to have a more integrated tutorial, but here’s a rough draft for now.) This is a summary of Koren’s 2008 ... [Read more...]

Measure theory studies ways of generalizing the notions of length/area/volume. Even in 2 dimensions, it might not be clear how to measure the area of the following fairly tame shape: much less the “area” of even weirder shapes in higher dimensions or different spaces entirely. For example, suppose you ... [Read more...]

(Way back when, I went through all the Netflix prize papers. I’m now (very slowly) trying to clean up my notes and put them online. Eventually, I hope to have a more integrated tutorial, but here’s a rough draft for now.) This is a summary of Bell and ... [Read more...]

The Kahn, Saks, and Sturtevant approach to the Evasiveness Conjecture (see the original paper here) is an epic application of pure mathematics to computer science. I’ll give an overview of the approach here, and probably try to add some more information on the problem in other posts. tl;dr ... [Read more...]

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I have recently discovered memisc, an extremely useful R package by Martin Elff (see his memisc page here). The package contains any number of useful functions, and is particularly good at helping one manage and recode survey data. However, by far my … Continue reading → [Read more...]

We've already seen two discrete probability distributions, the binomial and the hypergeometric. The binomial distribution describes the number of successes in a series of independent trials with replacement. The hypergeometric distribution describes th... [Read more...]

I was recently pointed in the direction of a thermal comfort model by the engineering company Arup (p27–28 of this pdf). Figure 3 at the top of p28 caught my attention. It’s mostly a nice graph; there’s not too much junk in it. One thing that struck me was ... [Read more...]