**F**ollowing the highly successful* [authorised opinion!, from objective sources]* MCMski IV, in Chamonix last year, the BayesComp section of ISBA has decided in favour of a two-year period, which means the great item of news that next year we will meet again for MCMski V [or MCMskv for short], this time on the snowy slopes of the Swiss town of Lenzerheide, south of Zürich. The committees are headed by the indefatigable Antonietta Mira and Mark Girolami. The plenary speakers have already been contacted and Steve Scott (Google), Steve Fienberg (CMU), David Dunson (Duke), Krys Latuszynski (Warwick), and Tony Lelièvre (Mines, Paris), have agreed to talk. Similarly, the nine invited sessions have been selected and will include Hamiltonian Monte Carlo, Algorithms for Intractable Problems (ABC included!), Theory of (Ultra)High-Dimensional Bayesian Computation, Bayesian NonParametrics, Bayesian Econometrics, Quasi Monte Carlo, Statistics of Deep Learning, Uncertainty Quantification in Mathematical Models, and Biostatistics. There will be afternoon tutorials, including a practical session from the Stan team, tutorials for which call is open, poster sessions, a conference dinner at which we will be entertained by the unstoppable Imposteriors. The Richard Tweedie ski race is back as well, with a pair of Blossom skis for the winner!

## Archive for the R Category

## MCMskv, Lenzerheide, Jan. 5-7, 2016

Posted in Kids, Mountains, pictures, R, Statistics, Travel, University life with tags ABC, BayesComp, Bayesian computation, Blossom skis, Chamonix, Glenlivet, Hamiltonian Monte Carlo, intractable likelihood, ISBA, MCMSki, MCMskv, Monte Carlo Statistical Methods, Richard Tweedie, ski town, STAN, Switzerland, Zurich on March 31, 2015 by xi'an## Le Monde puzzle [#904.5]

Posted in Books, Kids, R, Statistics, University life with tags arithmetics, Le Monde, mathematical puzzle, strsplit() on March 25, 2015 by xi'an**A**bout this #904 arithmetics Le Monde mathematical puzzle:

Find all pluralintegers, namely positiveintegers such that (a) none of their digits is zero and (b) removing their leftmost digit produces a dividing plural integer (with the convention that one digit integers are all plural).

a slight modification in the R code allows for a faster exploration, based on the fact that solutions add one extra digit to solutions with one less digit:

First, I found this function on Stack Overflow to turn an integer into its digits:

pluri=plura=NULL #solutions with two digits for (i in 11:99){ dive=rev(digin(i)[-1]) if (min(dive)>0){ dive=sum(dive*10^(0:(length(dive)-1))) if (i==((i%/%dive)*dive)) pluri=c(pluri,i)}} for (n in 2:6){ #number of digits plura=c(plura,pluri) pluro=NULL for (j in pluri){ for (k in (1:9)*10^n){ x=k+j if (x==(x%/%j)*j) pluro=c(pluro,x)} } pluri=pluro}

which leads to the same output

> sort(plura) [1] 11 12 15 21 22 24 25 31 32 33 35 36 [13] 41 42 44 45 48 51 52 55 61 62 63 64 [25] 65 66 71 72 75 77 81 82 84 85 88 91 [37] 92 93 95 96 99 125 225 312 315 325 375 425 [49] 525 612 615 624 625 675 725 735 825 832 912 [61] 915 925 936 945 975 1125 2125 3125 3375 4125 [70] 5125 5625 [72] 6125 6375 7125 8125 9125 9225 9375 53125 [80] 91125 95625

## the vim cheat sheet

Posted in Kids, Linux, R, University life, Wines with tags An Evil Guest, editor, unix, vim on March 18, 2015 by xi'an## amazing Gibbs sampler

Posted in Books, pictures, R, Statistics, University life with tags bayesm, convergence assessment, Gibbs sampler, Jean-Michel Marin, Markov chain Monte Carlo, mixtures, R on February 19, 2015 by xi'an**W**hen playing with Peter Rossi’s bayesm R package during a visit of Jean-Michel Marin to Paris, last week, we came up with the above Gibbs outcome. The setting is a Gaussian mixture model with three components in dimension 5 and the prior distributions are standard conjugate. In this case, with 500 observations and 5000 Gibbs iterations, the Markov chain (for one component of one mean of the mixture) has two highly distinct regimes: one that revolves around the true value of the parameter, 2.5, and one that explores a much broader area (which is associated with a much smaller value of the component weight). What we found amazing is the Gibbs ability to entertain both regimes, simultaneously.

## MissData 2015 in Rennes [June 18-19]

Posted in R, Statistics, Travel, University life with tags Brittany, conference, France, missing data, Rennes, Roderick Little, TGV on February 9, 2015 by xi'an**T**his (early) summer, a conference on missing data will be organised in Rennes, Brittany, with the support of the French Statistical Society [SFDS]. (Check the website if interested, Rennes is a mere two hours from Paris by fast train.)