Archive for Invalides

are pseudopriors required in Bayesian model selection?

Posted in Books, Kids, pictures, Statistics, University life with tags , , , , , , , , , , on February 29, 2020 by xi'an

An interesting question from X validated about constructing pseudo-priors for Bayesian model selection. Namely, how useful are these for the concept rather than the implementation? The only case where I am aware of pseudo-priors being used is in Bayesian MCMC algorithms such as Carlin and Chib (1995), where the distributions are used to complement the posterior distribution conditional on a single model (index) into a joint distribution across all model parameters. The trick of this construction is that the pseudo-priors can be essentially anything, including depending on the data as well. And while the impact the ability of the resulting Markov chain to move between spaces, they have no say on the resulting inference, either when choosing a model or when estimating the parameters of a chosen model. The concept of pseudo-priors was also central to the mis-interpretations found in Congdon (2006) and Scott (2002). Which we reanalysed with Jean-Michel Marin in Bayesian Analysis (2008) as the distinction between model-based posteriors and joint pseudo-posteriors.

the last argument of kings [jatp]

Posted in Statistics with tags , , , , , , , , , on January 21, 2019 by xi'an

le Dôme des Invalides [jatp]

Posted in Kids, pictures, Travel with tags , , , , , , , , on January 4, 2019 by xi'an

visiting musée Rodin

Posted in Books, Kids, pictures, Travel with tags , , , , , , , , , , , on February 27, 2016 by xi'an

A chance visit to the Rodin museum in Paris, a museum I had never visited before. Located in the classical Hôtel Biron [almost an anagram of Rodin!] and which was just renovated a few months ago, thanks to support from the French State and the Cantor Foundation. The building and gardens are superb, with the massive sculptures of the Bourgeois de Calais and the Porte de l’Enfer standing against the background of the golden dome of the Invalides…

I had a very vague idea of Rodin’s career and production, hence was quite impressed by the range of sculptures, casts, paintings and drawing he produced. While some sculptures kept a strong connection with classicism, the progressive distanciation from the official canons is striking. As is the series of sculptures as steps to the final realisation, most visible in the museum for the sculpture of Gustave Flaubert. I was quite impressed by the plaster cast of one of Flaubert’s gown, which manages to suggest the writer without any human representation.

The other obvious clue of this distanciation is the progressive inclusion of the raw material like marble in the sculpture, not only as a deconstructionist trick of “art in action” but also as a birth from the original silt. Some of the later pieces are striking annunciations of Picasso or Braque.

snapshot from the Rodin museum [#0]

Posted in pictures with tags , , , , on February 14, 2016 by xi'an