Archive for Morgiou

climbing Lothlorien in Middle Earth

Posted in Mountains, pictures, Travel, University life with tags , , , , , , on March 3, 2016 by xi'an

of For the Wednesday. afafternoon break of the Bayesian week at CIRM, a few of us enquired about the possibility of going climbing together and thanks to the good will of local Bayesian climbers ended effectively climbing on a nice type of rock with tiny finger holes! The set of routes was called Middle Earth (located near the notorious jail of Les Beaumettes and on the road to the Calanque de Morgiou) and the routes named after places in the Lord of the Rings. This was my first outdoor climb since the Cascades and while I was not in any way properly trained, I enjoyed this afternoon tremendously, no less for climbing a route called Lothlorien! (There are also Rohan and Gondor if you are partial to those other places…) But also for having a great time with old and new friends, in very mild weather and away from the blistery mistral wind. And for this residual tingling feeling at the end of my fingers…

fit for Les Calanques

Posted in Mountains, Running with tags , , , , , , , , , on March 1, 2016 by xi'an

Bayesian week in a statistics month at CIRM

Posted in Books, Mountains, pictures, Running, Statistics, Travel, University life, Wines with tags , , , , , , , , , , , on February 28, 2016 by xi'an

Calanque de Morgiou, Marseille, July 7, 2010As posted earlier, this week is a Bayesian week at CIRM, the French mathematical society centre near Marseilles. Where we meet with about 80 researchers and students interested in Bayesian statistics, from all possible sides. (And possibly in climbing in the Calanques and trail running, if not swimming at this time of year…) With Jean-Michel we will be teaching a short course on Bayesian computational methods, namely ABC and MCMC, over the first two days… Here are my slides for the MCMC side:

As should be obvious from the first slides, this is a very introductory course that should only appeal to students with no previous exposure. The remainder of the week will see advanced talks on the state-of-the-art Bayesian computational methods, including some on noisy MCMC and on the mysterious expectation-propagation technique.

le théorème de l’engambi

Posted in Books, Statistics with tags , , , , , , , on May 20, 2011 by xi'an

When I climbed in Luminy last year, one of the ways was called le théorème de l’engambi. Looking on the internet, I found this was the title of a book written by a local, Maurice Gouiran. The other evening, at the airport, the book was on sale in the bookstore, so I bought it and read it in the plane back to Paris. It is a local crime novel with highly local characters (to the point I do not understand all they say), local places like l’Estaque, the OM football club, La Gineste, Luminy, and what is apparently the most appealing theorem in novels, Fermat’s last theorem! (Engambi means messy affair in local dialect.) Overall the book is more pleasant to read for the local flavour than for the crime enquiry per se, especially because it involves scenes that take place in CIRM itself (including the restaurant and the terrace outside under the old oaks!). There is of course no indication on the nature of the three page proof produced by the first corpse of the book, but the description of the mathematical community is rather accurate, overall. The author mentions in a postnote that he is aware of Wiles’ proof, but believes (as a poet) in an alternative proof that Fermat had really found. (This book is not to be confused with Guedj’s parrot theorem, which is a novelesque story of mathematics, even though it ends up on the same premise that a parrot could recite Fermat’s proof…)

CoRe in CiRM [end]

Posted in Books, Kids, Mountains, pictures, R, Running, Statistics, Travel, University life with tags , , , , , , , , , , , , , on July 18, 2010 by xi'an

Back home after those two weeks in CiRM for our “research in pair” invitation to work on the new edition of Bayesian Core, I am very grateful for the support we received from CiRM and through it from SMF and CNRS. Being “locked” away in such a remote place brought a considerable increase in concentration and decrease in stress levels. Although I was planning for more, we have made substantial advances on five chapters of the book (out of nine), including a completely new chapter (Chapter 8) on hierarchical models and a thorough rewriting of the normal chapter (Chapter 2), which along with Chapter 1 (largely inspired from  Chapter 1 of Introducing Monte Carlo Methods with R, itself inspired from the first edition of Bayesian Core,!). is nearly done. Chapter 9 on image processing is also quite close from completion, with just the result of a batch simulation running on the Linux server in Dauphine to include in the ABC section. As the only remaining major change is the elimination of reversible jump from the mixture chapter (to be replaced with Chib’s approximation) and from the time-series chapter (to be simplified into a birth-and-death process). Going back to the CiRM environment, I think we were lucky to come during the vacation season as there is hardly anyone on the campus, which means no car and no noise. The (good) feeling of remoteness is not as extreme as in Oberwolfach, but it is truly a quality environment. Besides, being able to work 24/7 in the math library is a major plus. as we could go and grab any reference we needed to check. (Presumably, CiRM is lacking in terms of statistics books, compared with Oberwolfach, still providing most of the references we were looking for.) At last, the freedom to walk right out of the Centre into the national park for a run, a climb or even a swim (in Morgiou, rather than Sugiton) makes working there very tantalising indeed! I thus dearly hope I can enjoy again this opportunity in a near future…