Publications by xi'an
Le Monde puzzle [#737 re-read]
As a coincidence, while I was waiting for the solution to puzzle #737 published this Friday in Le Monde, the delivery (wo)man forgot to include the weekend magazine and I had to buy it this morning with my baguette (as if anyone cares!). The solution is (y0,z0,w0)=(38,40,46) and…it does not work! The value of (x1,y1,z1,w1) is indeed (19,39,43,...
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another lottery coincidence
Once again, meaningless figures are published about a man who won the French lottery (Le Loto) for the second time. The reported probability of the event is indeed one chance out of 363 (US) trillions (i.e., billions in the metric system. or 1012)… This number is simply the square of which is the number of possible loto grids. Thus, the probab...
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Posts of the year
Like last year, here are the most popular posts since last August: Home page 92,982 In{s}a(ne)!! 6,803 “simply start over and build something better” 5,834 Julien on R shortcomings 2,373 Parallel processing of independent Metropolis-Hastings algorithms 1,455 Do we need an integrated Bayesian/likelihood inference? 1,361 Coincidence in lotter...
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Le Monde puzzle [#738]
The Friday puzzle in Le Monde this week is about “friendly perfect squares”, namely perfect squares x2>10 and y2>10 with the same number of digits and such that, when drifting all digits of x2 by the same value a (modulo 10), one recovers y2. For instance, 121 is “friend” with 676. Here is my R code: xtrct=function(x){ x=as.integer(x) ...
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A misleading title…
When I received this book, Handbook of fitting statistical distributions with R, by Z. Karian and E.J. Dudewicz, from/for the Short Book Reviews section of the International Statistical Review, I was obviously impressed by its size (around 1700 pages and 3 kilos…). From briefly glancing at the table of contents, and the list of standard distr...
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Bayes-250, Edinburgh [day 2]
After a terrific run this morning to the top of Arthur’s Seat, and then around (the ribs are feeling fine, now!), the Bayes-250 talks were exhilarating and challenging. Jim Smith gave an introduction to the challenges of getting different experts to collaborate on a complex risk assessment, much in the spirit of his book, that got me wondering ...
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Le Monde puzzle [#739]
The weekend puzzle in Le Monde this week is again about a clock. Now, the clock has one hand and x ticks where a lamp is either on or off. The hand moves from tick to tick and each time the lights go on or off depending on whether or not both neighbours were in the same state the previous time. Here is my R code that describes the evolution o...
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Testing and significance
Julien Cornebise pointed me to this Guardian article that itself summarises the findings of a Nature Neuroscience article I cannot access. The core of the paper is that a large portion of comparative studies conclude to a significant difference between protocols when one protocol result is significantly different from zero and the other one(s) is...
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About commercial publishers
Julien Cornebise has [once again!] pointed out a recent Guardian article. It is about commercial publishers of academic journals, mainly Elsevier, Springer, and Wiley, with a clear stand from its title: “Academic publishers make Murdoch look like a socialist“! The valuable argument therein is that academic publishers make hefty profits (a 40%...
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Handbook of Markov chain Monte Carlo
At JSM, John Kimmel gave me a copy of the Handbook of Markov chain Monte Carlo, as I had not (yet?!) received it. This handbook is edited by Steve Brooks, Andrew Gelman, Galin Jones, and Xiao-Li Meng, all first-class jedis of the MCMC galaxy. I had not had a chance to get a look at the book until now as Jean-Michel Marin took it home for me from ...
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