Archive for Bretagne

the Kouign-Amann experiment

Posted in Kids, pictures, Travel with tags , , , , , , , on June 10, 2019 by xi'an

Having found a recipe for Kouign-Amanns, these excessive cookies from Britanny that are essentially cooked salted butter!, I had a first try that ended up in disaster (including a deep cut on the remaining thumb) and a second try that went better as both food and body parts are concerned. (The name means cake of butter in Breton.)The underlying dough is pretty standard up to the moment it starts being profusedly buttered and layered, again and again, until it becomes sufficiently feuilleté to put in the oven. The buttery nature of the product, clearly visibly on the first picture, implies the cookies must be kept in containers like these muffin pans to preserve its shape and keep the boiling butter from  inundating the oven, two aspects I had not forecasted on the first attempt.The other if minor drawback of these cookies is that they do not keep well as they contain so much butter. Bringing enough calories input for an hearty breakfast (and reminding me of those I ate in Cambridge while last visiting Pierre).

indecent exposure

Posted in Statistics with tags , , , , , , , , , , , , on July 27, 2018 by xi'an

While attending my last session at MCqMC 2018, in Rennes, before taking a train back to Paris, I was confronted by this radical opinion upon our previous work with Matt Moores (Warwick) and other coauthors from QUT, where the speaker, Maksym Byshkin from Lugano, defended a new approach for maximum likelihood estimation using novel MCMC methods. Based on the point fixe equation characterising maximum likelihood estimators for exponential families, when theoretical and empirical moments of the natural statistic are equal. Using a Markov chain with stationary distribution the said exponential family, the fixed point equation can be turned into a zero divergence equation, requiring simulation of pseudo-data from the model, which depends on the unknown parameter. Breaking this circular argument, the authors note that simulating pseudo-data that reproduce the observed value of the sufficient statistic is enough. Which is related with Geyer and Thomson (1992) famous paper about Monte Carlo maximum likelihood estimation. From there I was and remain lost as I cannot see why a derivative of the expected divergence with respect to the parameter θ can be computed when this divergence is found by Monte Carlo rather than exhaustive enumeration. And later used in a stochastic gradient move on the parameter θ… Especially when the null divergence is imposed on the parameter. In any case, the final slide shows an application to a large image and an Ising model, solving the problem (?) in 140 seconds and suggesting indecency, when our much slower approach is intended to produce a complete posterior simulation in this context.

Rennes street art #2 [jatp]

Posted in Kids, pictures, Travel, University life with tags , , , , , , , , , on July 7, 2018 by xi'an

Rennes street art [jatp]

Posted in Kids, pictures, Travel, University life with tags , , , , , , , , , on July 2, 2018 by xi'an

yet another opportunity in a summer of Briton conferences, free of charge!

Posted in Statistics with tags , , , , , , , on April 10, 2018 by xi'an

Breizh atav [Armor ha Argoat]

Posted in pictures with tags , , , , on October 2, 2011 by xi'an

Two “strong” pictures of Bretagne [Brittany] taken this summer by my friend Gilles Barés. Armor and Argoat are Breton for (land near the) sea or cost, and (land of the) forest or bocage. (Breizh atav [pronounced /a.ˈta.o/] means Bretagne for ever or eternal Bretagne.)

Happy B’Day, Normandie!

Posted in Kids with tags , , , on July 2, 2011 by xi'an

This is fairly silly, but my Norman genes cannot resist mentioning that Normandy is turning 1100 years old this year, following its official creation by the Treaty of Saint-Clair sur Epte between the French king Charles le Chauve and the Viking chief Rollon, …. (One of the terms of the Treaty was that Rollon converted to the Christian religion and he was baptised under the name of Robert! Although this Frankish name was already quite common in France from the 600’s, I for one am rather glad he did not stick to his Old Norse name of Hrólfr!!!) Of course, my Breton genes cannot any more avoid mentioning that Britanny was created as a kingdom close to a century earlier, under the king Nominoé…