Archive for research in pair

CoRe in CiRM [3]

Posted in Books, R, Statistics, University life with tags , , , , , , , , , , on July 11, 2010 by xi'an

Still drudging along preparing the new edition of Bayesian Core. I am almost done with the normal chapter, where I also changed the Monte Carlo section to include specific tools (bridge) for evidence/Bayes factor approximation. Jean-Michel has now moved to the new hierarchical model chapter and analysed longitudinal  datasets that will constitute the core of the chapter, along with the introduction of DAGs. (meaning some time “wasted” on creating DAG graphs, I am afraid!) He is also considering including a comparison with OpenBUGS and JAGS implementations, with the convincing motive that the hierarchical models are used in settings where practitioners have no time/ability to derive Gibbs samplers for a whole collection of models they want to compare… And we are  vaguely wondering whether or not using a pun in the title, from Bayesian Core to Bayesian CoRe, in order to emphasise the R link. This morning, it took me half an hour to figure out how resetting new counters (like our exercise environment) in LaTeX,

\makeatletter
\@addtoreset{exx}{chapter}
\makeatother

but I eventually managed it, thanks to the UK TeX Archive.

Core in CiRM [2]

Posted in Books, R, Statistics, University life with tags , , , , , , , on July 9, 2010 by xi'an

We are making slow progress on the normal and regression chapters as we decided to write the package at the same time we revise the chapters… Jean-Michel transformed the variable selection and model choice R codes of the regression chapter into generic functions that will fit within the package. I rewrote the section on testing, removing all connections to classical testing, 0-1 loss functions and 5% errors, towards a purely model-choice perspective. This does not modify the computational aspects but it makes the discourse more coherent and bypasses the debate about whether or not posterior probabilities are commensurable to p-values and all that. Last morning, I went running to the two creeks (locally called calanques) of Morgiou and Sugiton on a very nice costal trail.

Core in CiRM [1]

Posted in Books, Mountains, pictures, R, Running, Statistics, University life with tags , , , , , , , on July 7, 2010 by xi'an

Jean-Michel Marin and myself have thus started our “research in pair” in CIRM, Luminy, for a fortnight. We are working on the second edition of Bayesian Core and, despite working round the clock on the project (except for a one hour run around Mont Puget this morning), we are not going as fast as planned… Today, we worked in parallel on the normal and the regression chapters, looking for a sexy normal dataset to replace the larceny (normaldata) and the large and delicate CMB datasets. We eventually settled for a modern version of the Michelson-Morley dataset (available in R as morley), produced by K.K. Illingworth in 1927. I hope the spectral data and the relevance of the experiment will not be lost on the readers.