Blog Archives

9th IMACS seminar on Monte Carlo Methods, Annecy

July 17, 2013
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9th IMACS seminar on Monte Carlo Methods, Annecy

As astute ‘Og’s readers may have gathered (!), I am now in Annecy, Savoie, for the 9th IMACS seminar on Monte Carlo Methods. Where I was kindly invited to give a talk on ABC. IMACS stands for “International Association for Mathematics and Computers in Simulation” and the conference gathers themes and sensibilities I am not

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Le Monde puzzle [#827]

July 2, 2013
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Le Monde puzzle [#827]

Back to R (!) for the current Le Monde puzzle: Given an unknown permutation of the set {1,…,6}, written on the faces of a cube, there exist a sequence of summits such that increasing by one unit the three numbers of the faces sharing the successive summits in the sequence leads to identical values over

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integral priors for binomial regression

July 1, 2013
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integral priors for binomial regression

Diego Salmerón and Juan Antonio Cano from Murcia, Spain (check the movie linked to the above photograph!), kindly included me in their recent integral prior paper, even though I mainly provided (constructive) criticism. The paper has just been arXived. A few years ago (2008 to be precise), we wrote together an integral prior paper, published

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MCMSki IV, Jan. 6-8, 2014, Chamonix (news #6)

June 26, 2013
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MCMSki IV, Jan. 6-8, 2014, Chamonix (news #6)

More news about MCMSki IV: First, the 9 invited and the 16 contributed sessions are about to be set into the program by the scientific committee. It should appear any time now: stay tuned. Second, after looking a wee bit around for handling the abstract, I decided to create a dedicated blog, MCMSki IV: poster

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Le Monde puzzle [#825]

June 18, 2013
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Le Monde puzzle [#825]

Yet another puzzle which first part does not require R programming, even though it is a programming question in essence: Given five real numbers x1,…,x5, what is the minimal number of pairwise comparisons needed to rank them? Given 33 real numbers, what is the minimal number of pairwise comparisons required to find the three largest ones?

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Bayesian computational tools

June 17, 2013
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Bayesian computational tools

I just updated my short review on Bayesian computational tools I first wrote in April for the Annual Review of Statistics and Its Applications. The coverage is quite restricted, as I took advantage of two phantom papers I had started a while ago, one with Jean-Michel Marin, on hierarchical Bayes methods and on ABC. (As

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Le Monde puzzle [#824]

June 13, 2013
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Le Monde puzzle [#824]

A rather dull puzzle this week: Show that, for any integer y, (√3-1)2y+(√3+1)2y is an integer multiple of a power of two. I just have to apply Newton’s binomial theorem to obtain the result. What’s the point?! Filed under: Books, Kids, R Tagged: Binomial theorem, Isaac Newton, Le Monde, mathematical puzzle

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Le Monde puzzle [#822]

June 10, 2013
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Le Monde puzzle [#822]

For once Le Monde math puzzle is much more easily solved on a piece of paper than in R, even in a plane from Roma: Given a partition of the set {1,…,N} in k groups, one considers the collection of all subsets of  the set {1,…,N} containing at least one element from each group. Show

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Symmetric set differences in R

June 7, 2013
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My .Rprofile contains a collection of convenience functions and function abbreviations. These are either functions I use dozens of times a day and prefer not to type in full:## my abbreviation of head() h Or problems that I'd rather figure out once, and only once:## example: ## between( 1:10, 5.5, 6.5 ) between = low & x low & x...

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random sudokus

June 3, 2013
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random sudokus

In a paper arXived on Friday, Roberto Fontana relates the generation of Sudoku grids to the one of Latin squares (which is unsurprising) and to maximum cliques of a graph (more surprising). The generation of a random Latin square proceeds in three steps: generate a random Latin square L with identity permutation matrix on symbol

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