## a journal of the plague year [grey November reviews]

Posted in Books, Kids, Mountains, pictures, Travel with tags , , , , , , , , , , , , , , , , , , , , , , on November 21, 2020 by xi'an

Read Evil for Evil, K.J. Parker’s second tome in the Engineer trilogy, published in 2009! Surprisingly, I remembered enough of the first volume for the story to make sense and I enjoyed it, for the same reason I liked Sixteen ways to defend &tc., namely for its attention to logistics and medieval industry taking over the muscle-display of standard equivalents, plus the self-demeaning attitude of most characters, again a welcome change from the standards! The pace of the story sometimes get bogged down, though.

Slowly cooked pulled pork with a hellish amount of red peppers, meaning I ended up eating most of it by myself over a few days. Tried cauliflower risotto, and liked it. Took my mom to a nice restaurant in Caen, À Contre Sens, after an oyster breakfast with her on the quays of a nearby Channel harbour, with a surprise lunch based on local (Norman) products. Finding hardly anyone in the restaurant due to COVID regulations made the experience even more enjoyable. And such a difference from the previous Michelin we sampled this summer!

Wasted hours watching the US presidential vote counting slowly unraveling, computing & recomputing from the remaining ballots the required percentage of Biden’s votes towards catching up, and refreshing my NYT & Fivethirtyeight webpages way too often. And remain fazed by an electoral system stuck in a past when less than 50,000 men elected George Washington.

Cleaned up our vegetable patch after collecting the last tomatoes, pumpkins, and peppers. And made a few jars of green tomato jam, albeit not too sweet to be used as chutney!

Watched the TV series The Boys, after reading super-positive reviews in Le Monde and other journals. Which is a welcome satire on the endless sequence of super-heroes movies and series, by simply pushing on the truism that with super-powers does not come super-responsibility. Or even the merest hint of ethics. Plus some embarrassing closeness with the deeds and sayings of the real Agent Orange. Among the weaknesses, a definitive excess of blood and gore, ambiguous moral stands of the [far from] “good” guys who do not mind shooting sprees in the least, and some very slow episodes. Among the top items, the boat-meet-whale incident, “Frenchie” from Marseille almost managing a French accent when speaking some semblance of French, and Karl Urban’s maddening accent that’s a pleasure to listen even when I understand a sentence out of two, at best.

## Paris-Saclay campus debated in Nature

Posted in Books, University life with tags , , , , , , , , , , , on November 18, 2020 by xi'an

The newly created entity of the Paris-Saclay University is featuring in two editorials of Nature of 03 November for reaching a high ranking in one of the many league tables purportedly summarising the academic achievements of universities by a single number. This entity is made of the much older Université d’Orsay and of aggregated research institutes like Ecole Normale (formerly) de Cachan, Institut d’Optique, or Centrale Supélec, incidentally and uninterestingly located nearby my home. As an aggregate of high quality institutions, it is thus little surprise that it achieves a sufficient critical mass to reach a high ranking. Were the nearby Institut Polytechnique de Paris integrated as well, the ranking would have been even higher. (Why the two adjacent campuses did not merge defies rationality, but can be explained by politics and the long-standing opposition between Universités and Grandes Écoles in the French academic landscape.) I thus think the Nature editorial about the dangers to “the well-being of those on the academic front line” brought by the quest for high rankings is missing the point. By a fair margin. Indeed, it mixes the financial and institutional efforts made by [former president] Nicolas Sarkozy in creating a single campus with the funding of this mostly pre-existing campus [and in dire need of renovations, as exemplified by the new math department]. And seems to see the more competitive grant system in France connected with this creation when the [somewhat controversial] Agence Nationale de la Recherche in charge of the public-funded grants has been around since 2005. And I find that the unceasingly growing mille-feuille of aggregates, conglomerates, unions, initiatives, &tc. happening in the French academic landscape [like Paris Dauphine joining PSL a few years ago, whose status was confirmed today] are both blurring the picture and reducing the efficiency of the maneuvers by multiplying the administrative structures without creating a sense of belonging to a common institution. Plus ça change…

## a journal of the plague year [October reviews]

Posted in Books, Kids, Mountains, pictures, Travel with tags , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , on October 31, 2020 by xi'an

Read two more “little red” books from Éditions Guérin/Paulsen, the fantastic Chamonix editor, namely, Lénine à Chamonix by François Garde, a former Secretary-General of the Government of New-Caledonia, and Les Hallucinés (Un voyage dans les délires d’altitude), by Thomas Venin. The first book is a collection of short stories related to mountains, ranging from the realistic to the fantastic, and from good to terrible. I think in particular of the 1447 mètres story that involves a Holtanna like big wall in Iceland [good start then!], possibly the Latrabjarg cliff—although it stands at 1447 feet, not meters!, and the absurd impact of prime numbers on the failure of the climbing team. Lénine à Chamonix muses on the supposed day Vladimir Illitch “Lenin” Ulyanov spent in Chamonix in 1903, almost losing his life but adopting his alias there [which clashes with its 1902 first occurrence in publications!]. The second book is about high altitude hallucinations as told by survivors from the “death zone”. Induced by hypoxia, they lead hymalayists to see imaginary things or persons, sometimes to act against their own interest and often to die as a result. The stories are about those who survived and told about their visions. They reminded me of Abele Blanc telling us of facing the simultaneous hallucinations of two (!) partners during an attempt at Annapurna and managing to bring down one of the climbers, with the other managing on its own after a minor fall resetting his brain to the real world. Touching the limits of human abilities and the mysterious working of the brain…

Cooked several dishes suggested by the New York Times (!), including a spinach risotto [good], orecchiette with fennel and sausages [great], and malai broccoli [not so great], as well as by the Guardian’s Yotam Ottolenghi’s recipes, like a yummy spinash-potatoe pie. As Fall is seeping in, went back to old classics like red cabbage Flemish style. And butternut soups, starting with our own. And a pumpkin biryani!

Read Peter Hamilton’s Salvation, with a certain reluctance to proceed as I found the stories within mostly disconnected and of limited interest. (This came obviously as a disappointment, having enjoyed a lot Great North Road.) Unlikely I read the following volumes in the series. On the side, I heard that fantasy writer Terry Goodkind died on Sept. 17. He had written “The Sword of Truth” series, of which I read the first three volumes. (Out of 21 total!!!) While there were some qualities in the story, the setting was quite naïve (in the usual trope of an evil powerful character that need be fought at all costs) and the books carry a strong component of political conservatism as well as extensive sections of sadistic scenes

Watched Tim Burton’s 2012 Dark Shadows (terrible!) and a Taiwanese 2018 dark comedy entitled Dear Ex (誰先愛上他的) which I found rather interesting and quite original, despite the overdone antics of the mother. I even tried Tim Burton’s Sweeney Todd for a few minutes, being completely unaware this was a musical!

## inverse Gaussian trick [or treat?]

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

When preparing my mid-term exam for my undergrad mathematical statistics course, I wanted to use the inverse Gaussian distribution IG(μ,λ) as an example of exponential family and include a random generator question. As shown above by a Fortran computer code from Michael, Schucany and Haas, a simple version can be based on simulating a χ²(1) variate and solving in x the following second degree polynomial equation

$\dfrac{\lambda(x-\mu)^2}{\mu^2 x} = v$

since the left-hand side transform is distributed as a χ²(1) random variable. The smallest root x¹, less than μ, is then chosen with probability μ/(μ+x¹) and the largest one, x²=μ²/x¹ with probability x¹/(μ+x¹). A relatively easy question then, except when one considers asking for the proof of the χ²(1) result, which proved itself to be a harder cookie than expected! The paper usually referred to for the result, Schuster (1968), is quite cryptic on the matter, essentially stating that the above can be expressed as the (bijective) transform of Y=min(X,μ²/X) and that V~χ²(1) follows immediately. I eventually worked out a proof by the “law of the unconscious statistician” [a name I do not find particularly amusing!], but did not include the question in the exam. But I found it fairly interesting that the inverse Gaussian can be generating by “inverting” the above equation, i.e. going from a (squared) Gaussian variate V to the inverse Gaussian variate X. (Even though the name stems from the two cumulant generating functions being inverses of one another.)

## out of control…

Posted in Statistics with tags , , , , , , , , , on October 27, 2020 by xi'an