Archive for the pictures Category

a journal of the plague and pestilence [and war] year

Posted in Books, Kids, Mountains, pictures, Travel, University life with tags , , , , , , , , , , , , , , , , , , , , , on May 28, 2022 by xi'an

Received my first biking ticket ever, not for [cautiously!] Xing one of the 60⁺ red-lights on my bike route but for driving [most respectfully!] on the sidewalk in order to reach Dauphine as roads are currently under construction in the area, traffic is a mess, and bike lanes are closed. Had I realised this was at all possible (considering the absence of sanctions on reckless car and truck drivers!), I would have stopped before reaching the Paris traffic police which was already ticketing another cyclist.Read Upright Women Wanted [on Kindle, a courtesy gift from Tor] for just a few dozen pages and then almost gave up out of boredom! I found of limited literary or scenarist interest, despite its nominations to both Hugo and Locus Awards 2021, but finished it in the train to Roissy airport… I am still stuck (and much disappointed!) on the first pages of Susan Clarke’s Piranesi, as the story (?) takes place in an endless complex of empty rooms and the descriptions are endless. By comparison, the growing madness perspiring through the Gormenghast series is at least providing a leading line that makes it worth reading! Although it won the 2021 Women’s Prize for Fiction, and was praised everywhere and nominated for many prizes, imho, Piranesi stands as far as possible from Clarke’s earlier masterpiece Jonathan Strange & Mr. Norrell… I do not think I will manage to ever finish this book!

Cooked a batch of kouign amann but failed to include enough butter! Still eatable. And made a rather successful attempt at tortillas, following a NYT recipe.

Watched Witch at Court (마녀의 법정), which proposes a [of course] highly unrealistic story of an evil policeman turned politician and eventually being faced with his crimes by the daughter of one of his early victims. As often in K drama, everyone is connected to the case, with prosecutors being relatives of victims or culprits (but not bothered by conflicts of interest), red herrings abounding, and trial outcomes being decided on the flimsiest proofs. Nonetheless, this is the one series I (fast-forward) watched that addressed the most frontally women exploitation and sexual crimes.

PINTS [Paris/Ile-de-France NeuroTheory Symposium, 02/06/2022]

Posted in pictures, Travel, University life with tags , , , , , on May 25, 2022 by xi'an

angelic visit to Mt St Michel

Posted in pictures, Travel with tags , , , , , , on May 24, 2022 by xi'an

les urgences en PLS [Libé]

Posted in Kids, pictures with tags , , , , , on May 19, 2022 by xi'an

taking advantage of the constant

Posted in Books, Kids, pictures, R, Statistics, University life with tags , , , , , , , , on May 19, 2022 by xi'an

A question from X validated had enough appeal for me to procrastinate about it for ½ an hour: what difference does it make [for simulation purposes] that a target density is properly normalised? In the continuous case, I do not see much to exploit about this knowledge, apart from the value potentially leading to a control variate (in a Gelfand and Dey 1996 spirit) and possibly to a stopping rule (by checking that the portion of the space visited so far has mass close to one, but this is more delicate than it sounds).

In a (possibly infinite) countable setting, it seems to me one gain (?) is that approximating expectations by Monte Carlo no longer requires iid simulations in the sense that once visited,  atoms need not be visited again. Self-avoiding random walks and their generalisations thus appear as a natural substitute for MC(MC) methods in this setting, provided finding unexplored atoms proves manageable. For instance, a stopping rule is always available, namely that the cumulated weight of the visited fraction of the space is close enough to one. The above picture shows a toy example on a 500 x 500 grid with 0.1% of the mass remaining at the almost invisible white dots. (In my experiment, neighbours for the random exploration were chosen at random over the grid, as I assumed no global information was available about the repartition over the grid either of mass function or of the function whose expectation was seeked.)

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