It looks pretty cool! Wednesday, Jan 10 Invited Talk: Predictive information criteria in hierarchical Bayesian models for clustered data. Sophia Rabe-Hesketh and Daniel Furr (U California, Berkely) 10:40-11:30am Does the New York City Police Department rely on quotas? Jonathan Auerbach (Columbia U) 11:30-11:50am Bayesian estimation of mechanical elastic constants. ... [Read more...]

It looks pretty cool! Wednesday, Jan 10 Invited Talk: Predictive information criteria in hierarchical Bayesian models for clustered data. Sophia Rabe-Hesketh and Daniel Furr (U California, Berkely) 10:40-11:30am Does the New York City Police Department rely on quotas? Jonathan Auerbach (Columbia U) 11:30-11:50am Bayesian estimation of mechanical elastic constants. ... [Read more...]

It looks pretty cool! Wednesday, Jan 10 Invited Talk: Predictive information criteria in hierarchical Bayesian models for clustered data. Sophia Rabe-Hesketh and Daniel Furr (U California, Berkely) 10:40-11:30am Does the New York City Police Department rely on quotas? Jonathan Auerbach (Columbia U) 11:30-11:50am Bayesian estimation of mechanical elastic constants. ... [Read more...]

Jonah “ShinyStan” Gabry, Mike “Riemannian NUTS” Betancourt, and I will be giving a three-day short course next month in New York, following the model of our successful courses in 2015 and 2016. Before class everyone should install R, RStudio and RStan on their computers. (If you already have these, please update to ... [Read more...]

Jonah “ShinyStan” Gabry, Mike “Riemannian NUTS” Betancourt, and I will be giving a three-day short course next month in New York, following the model of our successful courses in 2015 and 2016. Before class everyone should install R, RStudio and RStan on their computers. (If you already have these, please update to ... [Read more...]

Jonah Gabry, Vince Dorie, and I are giving a 3-day short course in two weeks. Before class everyone should install R, RStudio and RStan on their computers. (If you already have these, please update to the latest version of R and the latest version of Stan, which is 2.10.) If problems ... [Read more...]

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I’m doing an analysis and one of the objects I’m working on is a multidimensional array called “attitude.” I took a quick look: __ dim(attitude) [1] 30 7 Huh? It’s not supposed to be 30 x 7. Whassup? I search through my scripts for a “attitude” but all I find is the ... [Read more...]

Bob Carpenter, Daniel Lee, and I are giving a 3-day short course in two weeks. Before class everyone should install R, RStudio and RStan on their computers. If problems occur please join the stan-users group and post any questions. It’s important that all participants get Stan running and bring ... [Read more...]

Suppose you have a data frame with a number of columns. You want to put the Trader and System columns first but you also want to do this in a flexible way. One approach would be to specify column numbers. This does the job but it's not very flexible. After ... [Read more...]

An interesting paper (Modelling the recent common ancestry of all living humans, Nature, 431, 562–566, 2004) by Rohde, Olson and Chang concludes with the words: Further work is needed to determine the effect of this common ancestry on patterns of genetic variation in structured populations. But to the extent that ancestry is considered ... [Read more...]

* If you see a bunch of [Math Processing Error] errors, you might want to try opening the page in a different browser. I have had some trouble with MathJax and Windows Explorer. There are various approaches to predicting Comrades Marathon finishing times. Lindsey Parry, for example, suggests that you use ... [Read more...]

Following up on my previous post about generating Sankey plots with the riverplot package. It's also possible to generate plots which have constant coloured edges. Here's how (using some of the data structures from the previous post too): The post A Sankey Plot with Uniform Coloured Edges appeared first on ... [Read more...]

A friend came to me with a question. The original question was a little complicated, but in essence it could be explained in terms of the familiar urn problem. So, here's the problem: you have an urn with 50 white balls and 9 black balls. The black balls are individually numbered. Balls ... [Read more...]

So... the Hypergeometric distribution (as used in one of my previous posts). That was a bit of overkill, wasn't it? To recap the problem: we have an urn filled with a selection of white and black balls. We want to calculate the probability that all of the white balls and ... [Read more...]

The cost of fuel in South Africa (and I imagine pretty much everywhere else) is a contentious topic. It varies from month to month and, although it is clearly related to the price of crude oil and the exchange rate, various other forces play an influential role. According to the ... [Read more...]

I have just been trying to import some data into R. The data were exported from a SQL Server client in tab-separated value (TSV) format. However, reading the data into R the "usual" way produced unexpected results: Those weird characters in the first record... where did they come from? They ... [Read more...]

The book R for Business Analytics by Ajay Ohri sets out to look at "some of the most common tasks performed by business analysts and helps the user navigate the wealth of information in R and its 4000 packages." In my opinion it succeeds in covering an extensive range of topics ... [Read more...]

I recently read an article which showed how to download Option Chain data from Google Finance using R. Interestingly, that article appears to be a close adaption of another article which does the same thing using Python. While playing around with the code from these articles I noticed a couple ... [Read more...]

Manfred Schroeder's book Fractals, Chaos, Power Laws is a fruitful source of interesting topics and projects. He gives a thorough description of Diffusion-Limited Aggregation (DLA) as a technique for simulating physical processes which produce intricate branching structures. Examples, as illustrated below, include Lichtenberg Figures, dielectric breakdown, electrodeposition and Hele-Shaw flow. ... [Read more...]