# Blog Archives

## tenured research position with ABC skills!

February 2, 2012
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I just received this announcement for the opening of a (tenured/civil servant) position in the national research institute in biostatistics, genetics, and agronomy, INRA: Position opening with profile Approximate inference techniques in complex systems Key activities and required skills: You will develop methodological research in the field of statistical inference for models used in environmental

## the birthday problem [X’idated]

February 1, 2012
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The birthday problem (i.e. looking at the distribution of the birthdates in a group of n persons, assuming a uniform distribution of the calendar dates of those birthdates) is always a source of puzzlement ! For instance, here is a recent post on Cross Validated: I have 360 friends on facebook, and, as

## ultimate R recursion

January 31, 2012
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One of my students wrote the following code for his R exam, trying to do accept-reject simulation (of a Rayleigh distribution) and constant approximation at the same time: which I find remarkable if alas doomed to fail! I wonder if there exists a (real as opposed to fantasy) computer language where you could introduce constants

## the Art of R Programming [guest post]

January 30, 2012
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(This post is the preliminary version of a book review by Alessandra Iacobucci, to appear in CHANCE. Enjoy !) As Rob J. Hyndman enthusiastically declares in his blog, “this is a gem of a book”. I would go even further and argue that The Art of R programming is a

## Le Monde puzzle [#755?]

January 27, 2012
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Le Monde puzzle of last weekend was about sudoku-like matrices. Consider an (n,n) matrix containing the integers from 1 to n². The matrix is “friendly” if the set of the sums of the rows is equal to the set of the sum of the columns. Find examples for n=4,5,6. Why is there no friendly matrix

## ABC [PhD] course

January 25, 2012
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As mentioned in the latest post on ABC, I am giving a short doctoral course on ABC methods and convergence at CREST next week. I have now made a preliminary collection of my slides (plus a few from Jean-Michel Marin’s), available on slideshare (as ABC in Roma, because I am also giving the course in

## non-stationary AR(10)

January 18, 2012
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In the revision of Bayesian Core on which Jean-Michel Marin and I worked together most of last week, having missed our CIRM break last summer (!), we have now included an illustration of what happens to an AR(p) time series when the customary stationarity+causality condition on the roots of the associated polynomial is not satisfied.

## Harmonic means, again again

January 9, 2012
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Another arXiv posting I had had no time to comment is Nial Friel’s and Jason Wyse’s “Estimating the model evidence: a review“. This is a review in the spirit of two of our papers, “Importance sampling methods for Bayesian discrimination between embedded models” with Jean-Michel Marin (published in Jim Berger Feitschrift, Frontiers of Statistical Decision

## 1500th, 3000th, &tc

January 7, 2012
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As the ‘Og reached its 1500th post and 3000th comment at exactly the same time, a wee and only mildly interesting Sunday morning foray in what was posted so far and attracted the most attention (using the statistics provided by wordpress). The most visited posts: Title Views Home page 203,727 In{s}a(ne)!! 7,422 “simply start over

## Example 7.17 in Introduction to Monte Carlo methods with R

January 4, 2012
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I received the following email about Introducing Monte Carlo Methods with R a few days ago: Hallo Dr. Robert, I  am studying your fine book for myself. There´s a little problem in examples 7.17 and 8.1: in the R code a function “gu” is used and a reference given to ex. 5.17, but I cann´t