Archive for amazon associates

[The Art of] Regression and other stories

Posted in Books, R, Statistics, University life with tags , , , , , , , , , , , , , , , , , , , on July 23, 2020 by xi'an

CoI: Andrew sent me this new book [scheduled for 23 July on amazon] of his with Jennifer Hill and Aki Vehtari. Which I read in my garden over a few sunny morns. And as Andrew and Aki are good friends on mine, this review is definitely subjective and biased! Hence to take with a spoonful of salt.

The “other stories’ in the title is a very nice touch. And a clever idea. As the construction of regression models comes as a story to tell, from gathering and checking the data, to choosing the model specifications, to analysing the output and setting the safety lines on its interpretation and usages. I added “The Art of” in my own title as the exercise sounds very much like an art and very little like a technical or even less mathematical practice. Even though the call to the resident stat_glm R function is ubiquitous.

The style itself is very story-like, very far from a mathematical statistics book as, e.g., C.R. Rao’s Linear Statistical Inference and Its Applications. Or his earlier Linear Models which I got while drafted in the Navy. While this makes the “Stories” part most relevant, I also wonder how I could teach from this book to my own undergrad students without acquiring first (myself) the massive expertise represented by the opinions and advice on what is correct and what is not in constructing and analysing linear and generalised linear models. In the sense that I would find justifying or explaining opinionated sentences an amathematical challenge. On the other hand, it would make for a great remote course material, leading the students through the many chapters and letting them experiment with the code provided therein, creating new datasets and checking modelling assumptions. The debate between Bayesian and likelihood solutions is quite muted, with a recommendation for weakly informative priors superseded by the call for exploring the impact of one’s assumption. (Although the horseshoe prior makes an appearance, p.209!) The chapter on math and probability is somewhat superfluous as I hardly fathom a reader entering this book without a certain amount of math and stats background. (While the book warns about over-trusting bootstrap outcomes, I find the description in the Simulation chapter a wee bit too vague.) The final chapters about causal inference are quite impressive in their coverage but clearly require a significant amount of investment from the reader to truly ingest these 110 pages.

“One thing that can be confusing in statistics is that similar analyses can be performed in different ways.” (p.121)

Unsurprisingly, the authors warn the reader about simplistic and unquestioning usages of linear models and software, with a particularly strong warning about significance. (Remember Abandon Statistical Significance?!) And keep (rightly) arguing about the importance of fake data comparisons (although this can be overly confident at times). Great Chapter 11 on assumptions, diagnostics and model evaluation. And terrific Appendix B on 10 pieces of advice for improving one’s regression model. Although there are two or three pages on the topic, at the very end, I would have also appreciated a more balanced and constructive coverage of machine learning as it remains a form of regression, which can be evaluated by simulation of fake data and assessed by X validation, hence quite within the range of the book.

The document reads quite well, even pleasantly once one is over the shock at the limited amount of math formulas!, my only grumble being a terrible handwritten graph for building copters(Figure 1.9) and the numerous and sometimes gigantic square root symbols throughout the book. At a more meaningful level, it may feel as somewhat US centric, at least given the large fraction of examples dedicated to US elections. (Even though restating the precise predictions made by decent models on the eve of the 2016 election is worthwhile.) The Oscar for the best section title goes to “Cockroaches and the zero-inflated negative binomial model” (p.248)! But overall this is a very modern, stats centred, engaging and careful book on the most common tool of statistical modelling! More stories to come maybe?!

a journal of the plague year [more deconfined reviews]

Posted in Books, Kids, pictures with tags , , , , , , , , , , , , , , , , , , on July 18, 2020 by xi'an

Took a copy of Room 10 by Åke Edwardson yet again on the book sharing shelves at Dauphine. And read it within a few days, with limited enthusiasm as the story proceeds quite sluggishly, every single clue is driven to its very end, e.g. detailing the examination of security recordings for pages!, the Swedish background is mostly missing, the personal stories of the policemen prove frankly boring, and the final explanations stand way beyond a mere suspension of belief. The book is back on the shelves.

Watched the beginning of the Salvation series and quickly gave up. Because I soon realised it had nothing to do with the Peter Hamilton’s trilogy. And because the story did not seem to get anywhere, despite the impending destruction of Earth by a massive asteroid, turning into an East versus West spy story. And because the scientific aspects and characters were plain ridiculous. And also because the secondary plot about whom should be saved in case of a destruction was quite distasteful in its primitive eugenism.

Read an Indriðason I had not yet read, Sons of dust [Synir duftsins], the first book he wrote, but ironically rather repetitive on the themes of missing fathers, child abuse, social consequences of the second World War allied occupation, found in the subsequent volumes. And a rather unconvincing plot, especially from a genetic engineering perspective. (The book is not currently available in English. I read it in French.)

Eventually came to watch There will be blood, the 2007 masterpiece by Paul Anderson, with Daniel Day-Lewis rendering so impressively the descent into madness of the oil tycoon and his thirst for absolute control, loosing his adopted son in the process. And unable to stop at exposing the duplicity of the preacher whom he fought the entire film. The ending is somewhat less impressive than the rest, maybe because all is finished, but it does not diminish the raw power of this tale. And the music track is perfect, with Brahms’ Violin Concerto as a leitmotiv. A journey into oily darkness…

souvenirs de Luminy

Posted in Books, Kids, pictures, Statistics, Travel, University life with tags , , , , , , , , , , , , , on July 6, 2020 by xi'an

a journal of the plague year [deconfited reviews]

Posted in Books, Kids, pictures, Running, Wines with tags , , , , , , , , , , , , , , , , , , , , , , , , on July 4, 2020 by xi'an

Found a copy of Humans by Donald Westlake on the book sharing shelves at Dauphine. And read it within a few hours, as it is very light reading but quite funny nonetheless. If hardly ranking as a mystery novel. Or crime novel, unless the crime is Gaiacide and the criminal God. Reminded me of the equally light Bobby Dollar series by Tad Williams. As the main character is an angel, falling for humans as he tries to steer them towards the Armageddon. The setting is the early 1990s, with the main scares being atomic disaster (Chernobyl) and the AIDS pandemic. Plus the rise of environmental worries and of Chinese autocracy. I put it back on the shelves on my next visit to Dauphine, hopefully for someone else to enjoy!

Baked radish stems with basil for making pesto, with a bit more bitterness than usual. Cooked plenty of fennel since this is fennel season. Continued making my weekly rhubarb preserve. Keeping the garden active, now watching squash vines invading new territory, hopefully with an eatable reward in the Fall. Tomatoes are growing incredibly fast as well..! Saw another fox in the Parc before official opening times, quite close if speeding away from me and barely avoiding bumping in a pair of greyhounds which fortunately sounded completely unconcerned.

Watched Children of Men after an exhausting week online for a grant panel. While a parabola for the coming collapse of civilisation under political, biological and environmental apocalypses [is there any meaning to use apocalyse in the plural tense!?] and a premonitory tale on Brexit and the buttressing of Britain [or Trump and his Big Wall mania] induced by anti-immigrant rethorics, the film is over the top in terms of plot and action, with symbolism taking over realism, even on the slightest degree, every shot being filled with references to religions and arts (like the Pink Floyd flying pig), to previous environmental disasters (with long shots of burning cows reminiscent of the mad cow crisis) and geo-political upheavals (including a Hamas type protest in the refugee camp, with a short appearance of a jeep with a French flag more reminiscent of the liberation of Paris in August 1944). Characters are charicaturesque, with a very Manichean division between very few good ones and mostly bad ones. The most ridiculous part of the scenario may well be the battle scene in the refugee camp [tanks versus pistols!]… Once again stunned by all the awards and praise piled upon that film.

Read two more volumes of the Witcher [bought during BayesComp for my son!]. One being Sword of Destiny and a series of short stories, like the first volume. The second Blood of Elves and the beginning of the novels. The first season on TV borrows mostly from the first two collections of short stories. Which are somewhat better than the novel, as the latter is very slow paced and overly sentimental. Not terrible, mind.

Completed with uttermost reluctance the Horde du Contrevent [translating as the windwalkers] by Alain Damasio (no English translation available, but an Italian version, l’Orda del Vento,  is). Book that I again picked for figuring in Le Monde 100 bes&tc list! And felt like constantly fronting a strong, icy wind when going through the pages of that unusual book. The style is unpleasant and rather pretentious, with numerous puns in French.. The story is one of a (religious? mystical?) group walking against the wind(s) for decades to reach the source of these winds and to find the last types of wind no one has ever met. Their dreary pilgrimage is described by the 23 membres of the group, called the Horde, with a heavy-handed typographical symbol at the start of each paragraph identifying who’s speaking (and a convenient page marker with all these symbols). A bit heavy handed as a polyphonic novel (appropriately composed in a Corsican retreat!) and even more in the crypt-Nietschean philosophy it carries… The background universe there is somehow eco-steam-punk, with the wind producing most of the energy. The most exciting part involves rather realistic ice climbing. However, I clearly stand in the small minority of those less than impressed by the book as it is highly popular among French readers, one of the highest printings in the Folio collection, with side products a BD (above) and a movie (in the making?). (And enough votes from fans to almost reach the 10 most favourite novels in Le Monde list. )

a journal of the plague year [deconfined reviews]

Posted in Books, Kids, pictures, Travel, Wines with tags , , , , , , , , , , , , , , , , , , , , , , , , , , on June 13, 2020 by xi'an

Watched two Korean films, Train to Busan and then Psychokinesis, both by Yeon Sang-Ho. The first one is a mostly traditional zombie action movie, loosing one character after another to the disease with a few funny moments. The second one is also involving supernatural features, rather poorly done, but it offers some political satire on a corrupted real estate project that make it somewhat tolerable. If barely.

Read (an old, cellar-relegated, somewhat mouldy) Henning Mankell’s Sidetracked (book #5 in the Kurt Wallander series), which was good enough to be enjoyable, albeit with a serial killer plot (always a lazy plot idea!), but it definitely made me regret the Martin Beck books of Sjowall and Wahloo which had a stronger social and political perspective (to the point of this book sounding like a pale replica). The more because Maj Sjowall passed away in early May. (Having survived Wahloo by 45 years and never revisiting the series.)

Baked more breads, including rye bread, and experimented with new dishes, like a jollof rice attempt with wild garlic, which tasted a wee too mild and took more time at the cleaning stage of the cocotte (French oven) than the cooking one. As it is one of these rice dishes like tahdig that call for a slightly burned bottom! Cooked several clafoutis with garden cherries and strawberries. Started making weekly rhubarb compote since available at the farmers’ market.

And now growing tomatoes and beans and peppers and onions and potatoes and butternut… We also found a woodcock most unusually and inexplicably stranded in the garden, feeling the worse for a cat attack as shown by a few feathers in the grass, but it was impossible to catch and hence protect from all the stray cats in the neighbourhood. After a day or two, we did not find any remain of the bird, so it presumably escaped.

Also watched A Sun (陽光普照), a psychological Taiwanese film about an “ordinary” family unraveling when the youngest son goes to jail. With an astounding Muter Courage as the central character. And a surprising sequence of characterial twists in the story that makes the movie less bleak that the first 30mn could induce, revealing layers in most characters that were carefully left hidden in the beginning of the film. (Except for the unfortunate girlfriend of A-Ho, who hardly utters a word and never seems to join the family.) With a beautiful final shot relating to the early years of A-Ho. (As one character is named A-Ho and another one A-Hao, it took me a while to spot the difference and stop thinking there were two parallel time-lines in the story!) A really strong film!

Succumbed (!) to ordering and reading the True Bastards, by Johnathan [pardon my] French. Which is the second volume in the Lot Lands trilogy and about as fun as the first volume, although the role of cursed magics is somehow over-done. But the change in this book from a male to a female viewpoint is definitely a worthwhile rarity in fantasy novels, showing how much harder the main character, Fetch, has to work to lead her troop of ½ orcs. And a constant threat of being belittled as such by other characters. (Any resemblance to real life problems being obviously coincidental!) Don’t expect real depth though, from the plot which keeps running in hogs’ circles to the point where everyone seems to be the hidden relative of everyone else (still alive!) to the underlying message, if any!

Got tricked by a Guardian article into watching The Vast of Nights. Frankly, I do not understand the praise heaped upon this academic-oh–so-academic exercise in film making! Yes, it does sound like the Twilight Zone, as the story is the usual trope on aliens being here with only the military being aware of it, trying to bank on their advanced technology, &tc. The hapless characters confuse agitation and action, while speaking, speaking, speaking all the time… It should have been a radio show. In the 1950’s. Not in the current times, already awash in conspiracy theories (although, far from it!, the film is clearly seen as an exercice de style recreating the mood of a 1960’s rural town in the South of the USA, with an endless sequence in a vintage car park).