Archive for book review

the liberation [book review]

Posted in Books with tags , , , , , , , , , , on July 9, 2021 by xi'an

The third volume of Ian Tregillis’ The Alchemy Wars arrived in the mail, and I could not resist bing-read it, induced by a heat wave that made anything close to serious work near impossible in the late afternoons… The characters are essentially the same, with two central (human) female characters whose trajectories once again converge to the critical point. Plus, two female robots playing a contrapunt. And the biblical Daniel, reborn from slavery into a free willed, tolerant and pacific being.

“The Clockmakers had been playing a losing game of catch-up (…) They were too soft, too coddled, too accustomed to standing atop the pile. They weren’t well suited to life as underdogs. They were not French.”

The core of the action takes place in Amsterdam, occupied by liberated robots, prone to pogroms as well as re-enslaving other robots. The weakness in the plot is that there is no strong reason these robots do not completely take over the formerly ruling Guild of Alchemists, and lengthy plot-resolving discussions between fighting characters always irk me no end, but the conclusion still feels proper, with the author not at all reluctant to hack at bits and pieces of his character to raise the body-count. À ls George Martin! And the mild philosophical musing about the reversal of dominant-dominated positions in this society are overall enjoyable if not particularly deep. Overall, a striking trilogy.

quick(er) calculations [book review]

Posted in Statistics with tags , , , , , , , , , , , , on July 5, 2021 by xi'an

Upon my request, Oxford University Press sent me this book for review in CHANCE. With the extended title How to add, subtract, multiply, divide, square, and square root more swiftly. This short (173 pages) book is written by Trevor Davis Lipscombe, currently Director of the Catholic University of America Press (which are apparently not suited for his books, since his former Physics of Rugby got published by Nottingham University Press). The concept of the book is to list tricks and shortcuts to handle seemingly tough operations on a list of numbers. Illustrated by short anecdotes mostly related to religion, sports (including the Vatican cricket team!), and history, albeit not necessarily related with the computation at hand and not providing an in-depth coverage of calculation across the ages and the cultures. While the topic is rather dry, as illustrated by the section titles, e.g., “Multiply two numbers that differ by 2, 4, 6, or 20” or “Multiply or divide by 66 or 67, 666 or 667” (!), the exposition is somewhat facilitated by the (classics) culture of the author. (I have to confess I got lost by the date chapter, i.e., finding which day of the week was December 18, 1981, for instance. Especially by the concept of Doomsday which I thought was a special day of the year in the UK. Or in the USA.) Still, while recognising some simple decompositions I also used for additions and subtractions, and acknowledging the validity of the many tricks I had never though of, I wonder at the relevance of learning those dozens of approaches beyond maintaining a particular type of mental agility… Or preparing for party show-time. Especially for the operations that do not enjoy exact solutions, like dividing by √3 or multiplying by π… The book reminded me of a physics professor in Caen, Henri Eyraud, who used to approximate powers and roots faster than it took us to get a slide rule out of our bags! But Guesstimation, which I reviewed several years ago, seemed more far-reaching that Quick(er) calculations, in that I had tried to teach my kids (with limited success) how to reach the right order of magnitude of a quantity, but never insisted [beyond primary school] on quick mental calculations. (The Interlude V chapter connects with this idea.)

[Disclaimer about potential self-plagiarism: this post or an edited version should eventually appear in my Books Review section in CHANCE.]

inf R ! [book review]

Posted in Books, R, Travel with tags , , , , , , , , , , , on June 10, 2021 by xi'an

Thanks to my answering a (basic) question on X validated involving an R code, R mistakes and some misunderstanding about Bayesian hierarchical modelling, I got pointed out to Patrick Burns’ The R inferno. This is not a recent book as the second edition is of 2012, with a 2011 version still available on-line. Which is the version I read. As hinted by the cover, the book plays on Dante’s Inferno and each chapter is associated with a circle of Hell… Including drawings by Botticelli. The style is thus most enjoyable and sometimes hilarious. Like hell!

The first circle (reserved for virtuous pagans) is about treating integral reals as if they were integers, the second circle (attributed to gluttons, although Dante’s is for the lustful) is about allocating more space along the way, as in the question I answered and in most of my students’ codes! The third circle (allocated here to blasphemous sinners, destined for Dante’s seven circle, when Dante’s third circle is to the gluttons) points out the consequences of not vectorising, with for instance the impressive capacities of the ifelse() function [exploited to the max in R codecolfing!].  And the fourth circle (made for the lustfuls rather than Dante’s avaricious and prodigals) is a short warning about the opposite over-vectorising. Circle five (destined for the treasoners, and not Dante’s wrathfuls) pushes for and advises about writing R functions. Circle six recovers Dante’s classification, welcoming (!) heretics, and prohibiting global assignments, in another short chapter. Circle seven (alloted to the simoniacs—who should be sharing the eight circle with many other sinners—rather than the violents as in Dante’s seventh) discusses object attributes, with the distinction between S3 and S4 methods somewhat lost on me. Circle eight (targeting the fraudulents, as in Dante’s original) is massive as it covers “a large number of ghosts, chimeras and devils”, a collection of difficulties and dangers and freak occurences, with the initial warning that “It is a sin to assume that code does what is intended”. A lot of these came as surprises to me and I was rarely able to spot the difficulty without the guidance of the book. Plenty to learn from these examples and counter-examples. Reaching Circle nine (where live (!) the thieves, rather than Dante’s traitors). A “special place for those who feel compelled to drag the rest of us into hell.” Discussing the proper ways to get help on fori. Like Stack Exchange. Concluding with the tongue-in-cheek comment that “there seems to be positive correlation between a person’s level of annoyance at [being asked several times the same question] and ability to answer questions.” This being a hidden test, right?!, as the correlation should be negative.

Introduction to Sequential Monte Carlo [book review]

Posted in Books, Statistics with tags , , , , , , , , , , , , , , , , on June 8, 2021 by xi'an

[Warning: Due to many CoI, from Nicolas being a former PhD student of mine, to his being a current colleague at CREST, to Omiros being co-deputy-editor for Biometrika, this review will not be part of my CHANCE book reviews.]

My friends Nicolas Chopin and Omiros Papaspiliopoulos wrote in 2020 An Introduction to Sequential Monte Carlo (Springer) that took several years to achieve and which I find remarkably coherent in its unified presentation. Particles filters and more broadly sequential Monte Carlo have expended considerably in the last 25 years and I find it difficult to keep track of the main advances given the expansive and heterogeneous literature. The book is also quite careful in its mathematical treatment of the concepts and, while the Feynman-Kac formalism is somewhat scary, it provides a careful introduction to the sampling techniques relating to state-space models and to their asymptotic validation. As an introduction it does not go to the same depths as Pierre Del Moral’s 2004 book or our 2005 book (Cappé et al.). But it also proposes a unified treatment of the most recent developments, including SMC² and ABC-SMC. There is even a chapter on sequential quasi-Monte Carlo, naturally connected to Mathieu Gerber’s and Nicolas Chopin’s 2015 Read Paper. Another significant feature is the articulation of the practical part around a massive Python package called particles [what else?!]. While the book is intended as a textbook, and has been used as such at ENSAE and in other places, there are only a few exercises per chapter and they are not necessarily manageable (as Exercise 7.1, the unique exercise for the very short Chapter 7.) The style is highly pedagogical, take for instance Chapter 10 on the various particle filters, with a detailed and separate analysis of the input, algorithm, and output of each of these. Examples are only strategically used when comparing methods or illustrating convergence. While the MCMC chapter (Chapter 15) is surprisingly small, it is actually an introducing of the massive chapter on particle MCMC (and a teaser for an incoming Papaspiloulos, Roberts and Tweedie, a slow-cooking dish that has now been baking for quite a while!).

the mechanical [book review]

Posted in Books, pictures with tags , , , , , , , , , , , , on June 4, 2021 by xi'an

Read this 2015 book by Ian Tregillis with growing excitement as I was first unsure why I had ordered it. It is a mix of the Baroque Cycle and of the Difference engine, with Huygens playing the central role (rather than Newton). The postulate of the story is that he found [in the 1600’s] a way to create robots (or mechanicals, or yet Clakkers) with autonomy, prodigious strength, and unlimited “life” time. Endowing the Netherlands with such an advantage as to become the unique European power. Except for a small population of French people, living in exile in Montréal, renamed as Marseille-in-the-West, where the descendants of Louis XIV were desperately fighting the Dutch robots with their barely sufficient chemical skills… In addition to this appealing alternate history, where the French are arguing about the free will of the machines, and building underground railways to convey rogue mechanicals outside the Dutch empire, partly for being Catholics and hence following the Pope’s doctrine [and partly to try to produce their own robots], where the Pope is also a refugee in Québec, and where New Amsterdam has not turned into New York, but is a thriving colonial city in America, linked to the mother country by mechanical boats and Zeppelin-like airships, the machines are constrained to obey the humans, with the Queen’s wishes at the top of a hierarchy of constraints. And no Asimov’s law to prevent them from being used as weapons, to the French’s sorrow! But their degree of autonomous thought is such that a mere loosening of a component may remove the compulsion and turn them into rogues, i.e, free willed robots. On the converse side, a nefarious guild in charge of a Calvinist faith and of the maintenance of the robots is attempting to extend this control of the Dutch State over some humans. Which makes for a great setting discussing the blurry border between humans and AIs, with both humans and Clakkers bringing their arguments to the game… I am now eagely waiting for the second and third volumes in the series of The Alchemy Wars to arrive in the mail to continue the story!