Boris from Ottawa sent me this email about Introducing Monte Carlo Methods with R: As I went through the exercises and examples, I believe I found a typo in exercise 6.4 on page 176 that is not in the list of typos posted on  your website.  For simulation of Gamma(a,1) random ... [Read more...]

Yet another paper on ABC model choice was posted on arXiv a few days ago, just prior to the ABC in London meeting that ended in the pub above (most conveniently located next to my B&B!). It is written by Olivier Francois and Guillaume Laval and the approach relies ... [Read more...]

Two types of R users My overwhelming impression from UseR 2010 is that, generally speaking, there are 2 types of regular R users -- those who have heard and are made uncomfortable by the idea of the *apply() functions, and those who really get it. In ... [Read more...]

In Tangente n⁰42, there was a [Latter, 1902] dataset about the size of cuckoo eggs against the species (goldcrest and warbler) which built the nest. (The whole dataset from Latter is analysed in Maindonald and Braun’s Data Analysis and Graphics Using R, with a degree of caution about how trustworthy ... [Read more...]

Julien just signaled an intermitent disappearance of the posts on the ‘Og, depending on the operating system: Ubuntu 10.10 seems to be working (most of the time!) while Mac and Windows are having problems… This is beyond my abilities, I have contacted WordPress support, maybe they are working on some new ... [Read more...]

The March 2011 issue of JASA contains a review of Introducing Monte Carlo Methods with R by Hedibert Lopes. As in the previous review, the poor quality of the figures is (rightly) pointed out by Hedie. However, the main message of the review remains very positive and, furthermore, Hedie advertises the ‘... [Read more...]

Although the official deadline is long past, I just became aware of this call for a postdoctoral position in Paris starting next Fall. Please feel free to apply: Summary Adaptive Markov Chain Monte Carlo (MCMC) methods are currently a very active field of research. MCMC methods are sampling methods, based ... [Read more...]

Here is an email that could appeal to some readers: Job in Cambridge MRC-BSU – Bayesian statistician Career development fellow MRC Biostatistics Unit, Cambridge We are offering an exciting opportunity to work on Bayesian models for infectious disease dynamics. A statistician is required to contribute to a programme of research to ... [Read more...]

Another book I received from the Short Book Reviews section of the International Statistical Review is Everitt’s and Hothorn’s Handbook of statistical analyses using R. Here is a [blog-ified] version of my book review. This book is the second (blue) edition of a successful (violet) handbook that can ... [Read more...]

Following the comments on our earlier submission to PNAS, we have written (and re-arXived) a revised version where we try to spell out (better) the distinction between ABC point (and confidence) estimation and ABC model choice, namely that the problem was at another level for Bayesian model choice (using posterior ... [Read more...]

A link on R-bloggers signaled a series of blogs and videos by IBM Netezza about Thomas Bayes and the consequences of his theorem. Which made me realise this was indeed the 250th anniversary of his death, and that maybe we (as a collective, incl. ISBA) should have done something on ... [Read more...]

For my second lecture today, I need to plot a likelihood surface for a basic two-component mixture with only the means unknown: here is the R code to speed up things llsurf=function(trumyn=2.,wayt=.3,var2=1.,ssiz=500){ # draws the log-likelihood surface and a random sample sd2=sqrt(var2) parti=(runif(... [Read more...]

This week, Le Monde offers not one but three related puzzles: Is it possible to label the twelve edges of a cube by consecutive numbers such that the sum of the edge numbers at any of the eight nodes is constant? Is it possible to label the eight nodes of ... [Read more...]

As I already did two years ago, in connection with the double degree between UAM and Dauphine, I will give a short graduate course at the Universidad Autonoma de Madrid (UAM). It will be part of the regular fourth year statistics course and will focus on mixtures, as given in ... [Read more...]

Following my earlier post on Buffon’s needle and Bertrand’s paradox, above are four outcomes corresponding to four different generations (among many) of the needle locations. The upper right-hand side makes a difference in the number of hits (out of 1000). The R code corresponding to this generation was made ... [Read more...]

When Peter Diggle gave his “short history” of spatial statistics this morning (I typed this in the taxi from Charles de Gaulle airport, after waiting one hour for my bag!), he started with a nice slide about Buffon’s needle (and Buffon’s portrait), since Julian Besag was often prone ... [Read more...]

Another mathematical puzzle from Le Monde that relates to a broken calculator (skipping the useless tale): Given a pair of arbitrary positive integers (x,y) a calculator can either substract the same integer [lesser than min(x,y)] from both x and y or multiply either x or y by 2. ... [Read more...]

(This post got published on The Statistics Forum yesterday.) The short book review section of the International Statistical Review sent me Raquel Prado’s and Mike West’s book, Time Series (Modeling, Computation, and Inference) to review. The current post is not about this specific book, but rather on why ... [Read more...]

In what seems like an endless cuRse, I found this week I had to re-grade a dozen R exams a TA’s did not grade properly! The grades I (X) got are plotted below against those of my TA (Y). There is little connection between both gradings… As if this ... [Read more...]

This morning, I noticed that none of my R related posts had appeared on R-bloggers for the past fortnight… After investigating, this was caused by…cut-and-paste! Indeed, when advertising about the special issue of TOMACS Arnaud Doucet and I edit about Monte Carlo methods in Statistics, I copied the main ... [Read more...]