Yesterday, Andrew Thomas and José Blanchet posted a note on the Bernouilli factory on arXiv. This short paper links with the recent paper of Flegal and Herbei I commented earlier. Considering the special target Thomas and Blanchet develop an elaborate scheme of cascading envelopes that converge to f from above. ... [Read more...]

In search of bin countsI look at histograms and density functions of my data in R on a regular basis. I have some idea of the algorithms behind these, but I've never had any reason to go under the hood until now. Lately, I've been looking using the b... [Read more...]

[Warning: this post about a race I ran yesterday is unlikely to be of interest for most readers!] Following my (un)reasonable time last year, I registered again for the annual “Cross de Bercy”  run by the Sport Club of the Finance Ministry (with whom/which CREST is affiliated). This ... [Read more...]

My neighbour is an half-retired entrepreneur who still runs his electric engine company. A few weekends ago, he came to me with the following physics question related with one of those engines: given a primary disk rotating at the angular speed of ω0 and a secondary disk located on the first ... [Read more...]

Following a link on R-bloggers, I ended up on this page (with a completely useless graph that only contained the pieces of information 5% in 1900 and 55% in 2000). The author (Ralph Keeney) reports on “A remarkable 55 percent of deaths for people age 15 to 64 can be attributed to decisions with readily [...] [Read more...]

Through the webpage of the Advanced Monte Carlo Methods I & II, given a few years ago by Michael Mascagni at ETH Zürich, I found a link to the scanned version of the 1964 book Monte Carlo Methods by Hammersley and Handscomb. This is a short book, with less than 150 pages, ... [Read more...]

The most visited post ever on the ‘Og was In{s}a(ne), my report on Radford Neal’s experiments with speeding up R by using different brackets (the second most populat was Ross Ihaka’s comments, “simply start over and build something better”). I just spotted two new entries ... [Read more...]

“We don’t need likelihood functions; we just need to know how to simulate from [them] (…) We don’t need models with sufficient statistics; we just need summary statistics (…) We don’t need to be Bayesian; we just need to be approximately so. We don’t need theory to tell ... [Read more...]

The 24 questions asked by John Halton in the conclusion of his 1970 survey are Can we obtain a theory of convergence for random variables taking values in Fréchet spaces? Can the study of Monte Carlo estimates in separable Fréchet spaces give a theory of global approximation? When sampling functions, ... [Read more...]

“The only good Monte Carlos are the dead Monte Carlos” (Trotter and Tukey, quoted by Halton) When I presented my [partial] history of MCM methods in Bristol two months ago, at the Julian Besag memorial, Christophe Andrieu mentioned a 1970 SIAM survey by John Halton on A retrospective and prospective survey ... [Read more...]

I received at last my weekend edition of Le Monde and hence the solution proposed by the authors (Cohen and Busser) to the puzzle #14. They obtain a strategy that only requires at most 19 steps. The idea is to start with a first test, which gives a reference score S0, and ... [Read more...]

Last week Le Monde puzzle (I have not received this week issue yet!) was about deriving an optimal strategy in less than 25 steps for finding the 25 answers to a binary multiple choice test, when at each trial, only the number of correct answers is known. Hence, if the correct answers ... [Read more...]

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...]