Course: 1st Italian Astrostatistics School, 12-16 June 2017

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Stefano Andreon writes:

We are pleased to announce the 1st Italian Astrostatistics School that will be held at INAF-Osservatorio Astronomico di Brera, Milano from 12 to 16 June 2017.

The primary goal of the school is to train astronomers to the use of modern statistical techniques, specifically parameter estimation and model selection. The INTENSIVE course, lectured by Stefano Andreon and Roberto Trotta, is characterized by extended laboratory sessions (i.e. individual work at the computer), taking about two thirds of the school attendance. The capacity is limited to 35 participants (first come first served
basis). The school is open to PhD students in astronomy, who have priority  (they should register by May 15th), and if space allows, to post-docs and researchers. From May 15th, registration is open to all (subject to availability). Attendance to the course has pre-requirements. For school program, details, and registration see:

http://iaa.mi.oa-brera.inaf.it/IAA/AstroStatisticsSchool.html

Bayescomp 2018

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Photo by Richard Aparicio

Bayescomp 2018 will be held in Barcelona, Spain, on 26-29 March. This is the successor to the MCMski conference series.

Bayes Comp 2018 is a biannual conference sponsored by the ISBA section of the same name. The conference and the section both aim to promote original research into computational methods for inference and decision making and to encourage the use of frontier computational tools among practitioners, the development of adapted software, languages, platforms, and dedicated machines, and to translate and disseminate methods developed in other disciplines among statisticians.

See the conference web site for more details. Note that I am not involved in the organisation of the conference, I am just disseminating the information.

JAGS tutorial at useR! 2017

I am giving a pre-conference tutorial on JAGS at useR! 2017 in Brussels on 4 July. You can see the outline of the tutorial on the conference website along with the other tutorials being given the same day.

This is my first pre-conference tutorial. Last year I gave a three day course on JAGS at the University of Zurich, so I have plenty material. My main problem is not over-filling the 3-hour time slot.

A Bayesian Information Criterion for Singular Models

On Wednesday, Mathias Drton and I will be presenting a read paper on Bayesian model choice for singular models at the Royal Statistical Society in London. You can read more about it on the RSS web site , where you can also download a preprint. The paper is scheduled to appear, with the discussion, in Series B of the Journal of the Royal Statistical Society next year.

The CRAN package sBIC by Luca Weihs implements the ideas in the paper and includes a series of vignettes that allow you to step through some of the examples in the paper.

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You can always make it faster…

… but sometimes you just need a good example to show you how. Saana Isojunno from the University of Saint Andrews wrote to me with an example that stopped working when she upgraded from JAGS 3.4.0 to JAGS 4.2.0. Saana’s model showed the classic signs of a memory leak. Compilation was very slow and memory consumption increased until all available RAM was used and the process was killed by the operating system. Continue reading

New Windows binary for R 3.3.0

Updated 22 June 2016

One of the important changes in this release 3.3.0 of R is the use of a new toolchain for  Windows. Unfortunately, for packages written in C++, the new toolchain is incompatible with the old one. So I had to build a new version of JAGS for use with R 3.3.0 and above.

When you upgrade to R 3.3.0 or higher you will need to remove the current installed version of JAGS (using the Control Panel) and run the  JAGS-4.2.0-Rtools33.exe installer. Then you will be able to install the binary rjags package from CRAN.

If you continue to use R 3.2.5 or earlier then you should not use the new installer but should continue to use  JAGS-4.2.0.exe.

Q: Why is this important?

A: If you install a version of JAGS that does not match your R installation then the rjags package will spontaneously crash.

Q: Why is this happening?

A: The Rtools compiler creates binaries that are statically linked to the C++ runtime. This is good because it means that R does not need to ship with a dynamic link library (DLL) for the C++ runtime (avoiding DLL Hell). It is harmless for the vast majority of R packages that are completely self contained. However, it is a problem for packages that need to interface to an external C++ DLL. Both the R package (e.g. rjags) and the external DLL (e.g. JAGS) must be compiled with the same compiler.

Q: This is a bit awkward isn’t it?

Yes it is awkward for JAGS users. However, in terms of the management of R packages this is a minority issue. As far as I know, the only other R packages affected are the ones that interface to SYMPHONY, gdal, and QuantLib.