Recently I gave a presentation on Machine Learning to members of the NYC Open Data Meetup group.Here is that presentation for anyone interested. Machine Learning - Ilan Man ...

Rolling forecasts are commonly used to compare time series models. Here are a few of the ways they can be computed using R. I will use ARIMA models as a vehicle of illustration, but the code can easily be adapted to other univariate time series models. One-step forecasts without re-estimation The simplest approach is to estimate the model on a single set of training data, and then compute one-step forecasts…

While working with Andrew and a student from Dauphine on importance sampling, we wanted to assess the distribution of the resulting sample via the Kolmogorov-Smirnov measure where F is the target. This distance (times √n) has an asymptotic distribution that does not depend on n, called the Kolmogorov distribution. After searching for a little while, […]

Check out John Cochrane's recent NBER post if you didn't already. It ends with:A last thought. Economic Fluctuations [an NBER program] merged with Growth [another NBER program] in the mid 1990s. At the time there was a great confluence of method as we...

The other day I fit a simple model to estimate team abilities from World Cup outcomes. I fit the model to the signed square roots of the score differentials, using the square root on the theory that when the game is less close, it becomes more variable. 0. Background As you might recall, the estimated […] The post Stan World Cup update appeared first on Statistical Modeling, Causal Inference, and…

As promised, I got back to this book, Implementing reproducible research (after the pigeons had their say). I looked at it this morning while monitoring my students taking their last-chance R exam (definitely last chance as my undergraduate R course is not reconoduced next year). The book is in fact an edited collection of papers […]

0. July 20, 2014: Some of the comments to this post reveal that using the word “fallacy” in my original title might have encouraged running together the current issue with the fallacy of transposing the conditional. Please see a newly added Section 7. 1. What you should ask… Discussions of P-values in the Higgs discovery invariably recapitulate many […]

There’s a story that (some) physicists and science reporters seem to like, which is the idea that some clever mathematician or physicist can derive universal laws of social behavior. It’s time to tell you all: Hari Seldon never existed. Here’s what I think of these stories of physicists who discover the laws of society. I […] The post “Building on theories used to describe magnets, scientists have put together a…

Michael Gutmann (University of Helsinki) recently wrote me with some comments on the Poisson transform paper (here). It turns out that the Poisson likelihood we define in the paper is a special case of more general frameworks he has worked on, the most recent being: M.U. Gutmann and J.Hirayama (2011). Bregman Divergence as General Framework […]

Mon: “Building on theories used to describe magnets, scientists have put together a model that captures something very different . . .” Tues: Questions about “Too Good to Be True” Wed: “The Europeans and Australians were too eager to believe in renal denervation” Thurs: Ethics and statistics Fri: Differences between econometrics and statistics: From varying […] The post On deck this week appeared first on Statistical Modeling, Causal Inference, and…

In my four years of blogging, the post that has generated the most comments is "How to handle negative values in log transformations." Many people have written to describe data that contain negative values and to ask for advice about how to log-transform the data. Today I describe a transformation […]

Michael Betancourt announces: The Stan Development Team is happy to announce the first Stan London Meetup, Wednesday, July 16th, 6-8 PM Bentham House, Seminar Room 4 4-8 Endsleigh Gardens, London, WC1H 0EG Nominally the plan is to begin with a casual introduction to Stan and then break out into discussion based on the interests of […] The post Stan London Meetup 16 July appeared first on Statistical Modeling, Causal Inference,…

I thought it would be fun to fit a simple model in Stan to estimate the abilities of the teams in the World Cup, then I could post everything here on the blog, the whole story of the analysis from beginning to end, showing the results of spending a couple hours on a data analysis. […] The post Stan goes to the World Cup appeared first on Statistical Modeling, Causal…

The new rules for D&D 5e (formerly known as D&D Next) are finally here: Dungeons & Dragons, 5th Edition: Basic Rules D&D 5e introduces a new game mechanic, advantage and disadvantage. Basic d20 Rules Usually, players roll a 20-sided die (d20) to resolve everyting from attempts at diplomacy to hitting someone with a sword. Each […] The post D&D 5e: Probabilities for Advantage and Disadvantage appeared first on Statistical Modeling,…

Two short items in this blogpost. Since it was not obvious how to run odfWeave() in my particular setup, the call I am using. Then there were several people crosstabulating logical vectors, so I wanted to play along, 80 times faster than table().odfWea...