Archive for the Kids Category

The CS detective

Posted in Books, Kids, Travel, University life with tags , , , , , , , on October 29, 2016 by xi'an

A few weeks ago, I received a generic email from No Starch Press promoting The CS Detective, and as I had liked their earlier Statistics Done Wrong, I requested a review copy of the book. Which I received in Warwick while I was there, last week. And read over my trip back to Paris. As it is a very quick read.

“The trouble with having an open mind, of course, is that people will insist on coming along and trying to put things in it.” T. Pratchett

The idea of the book is to introduce some concepts of tree searching algorithms through a detective-cum-magic story, a very shallow story if somewhat à la Terry Pratchett. (While this reference does not appear in the book, there are enough mentions made of turtles to suspect the filiation. Even though it is turtles all the way down. Hence I could not swear Frank Runtime was 100% inspired from Sam Vimes. But it rhymes.) I cannot say I am a bit fan of this approach as the story is an hindrance rather than an help, I do not find it particularly funny or enticing, and I keep wishing for the next concept to appear to end the current chapter and its inane plot. Of course, once the story is set aside, the book contains not that much in terms of search algorithms, because they all are limited to discrete tree structures. Namely, exhaustive, binary, breadth- and depth-first, iterative deepening, best-first, search algorithms, along with the notions of arrays, queues, stacks, and heaps. This fills about 50 pages of technical vignettes found at the end of each chapter…

So I end up wondering at what age this book would appeal to a young reader. Trying to remember from my own experience with summer vacation riddle and puzzle books, I would think the range 10-12 could be most appropriate although mileage will vary. Since the author, Jeremy Kubica, animates the Computational Fairy Tales blog with stories of the same flavour, you may start by tasting and testing this approach to popular science before getting the entire book

Fool’s quest [book review]

Posted in Books, Kids with tags , , , , , , , on October 23, 2016 by xi'an

Although I bought this second volume in the Fitz and the Fool trilogy quite a while ago, I only came to read it very recently. And enjoyed it unreservedly! While the novel builds upon the universe Hobb created in the liveship traders trilogy (forget the second trilogy!) and the Assassin and Fool trilogies, the story is compelling enough to bring out excitement and longing for further adventures of Fitz and the Fool. Many characters that were introduced in the earlier volume suddenly take on substance and meaning, while the main characters are no longer heroes of past eras, but also acquire further depth and subtlety. Even long-lasting ones like Chade. I cannot tell whether this new dimension of the plights affecting the Six Duchies and its ruler, King Verity, was conceived from the start or came later to the author, but it really fits seamlessly and increases by several orders of magnitude the epic feeling of the creation. Although it is hard to rank this book against the very first ones, like Royal Assassin, I feel this is truly one of the best of Hobb’s books, with the right mixture of action, plotting, missed opportunities and ambiguous angles about the main characters. So many characters truly come to life in this volume that I bemoan the sluggish pace of the first one even more now. While one could see Fool’s Quest as the fourteenth book in the Realm of the Elderlings series, and hence hint at senseless exploitation of the same saga, there are just too many new threads and perspective there to maintain this posture. A wonderful book and a rarity of a middle book being so. I am clearly looking forward the third instalment!

positions in French universities [deadline]

Posted in Kids, Statistics, University life with tags , , , , , , , on October 21, 2016 by xi'an

Université Paris-DauphineFor ‘Og’s readers interested in lecturer or professor positions in French universities next academic year, including a lecturer position at Paris-Dauphine in applied and computational statistics!, you need to apply for a qualification label by a national committee which strict deadline is next Tuesday, October 25, at 4pm (Paris/CET time).  (The whole procedure is exclusively in French!)


Posted in Kids, Travel, Wines with tags , , , on October 20, 2016 by xi'an

a grim knight [cont’d]

Posted in Books, Kids, pictures, R, Statistics with tags , , , , , , , on October 20, 2016 by xi'an

As discussed in the previous entry, there are two interpretations to this question from The Riddler:

“…how long is the longest path a knight can travel on a standard 8-by-8 board without letting the path intersect itself?”

riddlerechckas to what constitutes a path. As a (terrible) chess player, I would opt for the version on the previous post, the knight moving two steps in one direction and one in the other (or vice-versa), thus occupying three squares on the board. But one can consider instead the graph of the moves of that knight, as in the above picture and as in The Riddler. And since I could not let the problem go I also wrote an R code (as clumsy as the previous one!) to explore at random (with some minimal degree of annealing) the maximum length of a self-avoiding knight canter. riddlerechkThe first maximal length I found this way is 32, although I also came by hand to a spiralling solution with a length of 33.

riddlerechckRunning the R code longer over the weekend however led to a path of length 34, while the exact solution to the riddle is 35, as provided by the Riddler (and earlier in many forms, including Martin Gardner’s and Donald Knuth’s).

[An unexpected side-effect of this riddle was ending up watching half of Bergman’s Seventh Seal in Swedish…]

Nature highlights

Posted in Books, Kids, pictures, Statistics with tags , , , , , , , , , , , , , on October 16, 2016 by xi'an

Among several interesting (general public) entries and the fascinating article reconstituting the death of Lucy by a fall from a tree, I spotted in the current Sept. 22 issue of Nature two short summaries involving statistical significance, one in linguistics about repeated (and significant) links between some sounds and some concepts (like ‘n’ and ‘nose’) shared between independent languages, another about the (significant) discovery of a π meson and a K meson. The first anonymous editorial, entitled “Algorithm and blues“, was rather gloomy about the impact of proprietary algorithms on our daily life and on our democracies (or what is left of them), like the reliance on such algorithms to grant loan or determining the length of a sentence (based on the estimated probability of re-offending). The article called for more accountability of such tools, from going completely open-source to allowing for some form of strong auditing. This reminded me of the current (regional) debate about the algorithm allocating Greater Paris high school students to local universities and colleges based on their grades, wishes, and available positions. The apparent randomness and arbitrariness of those allocations prompted many (parents) to complain about the algorithm and ask for its move to the open. (Besides the pun in the title, the paper also contained a line about “affirmative algorithmic action”!) There was also a perfectly irrelevant tribune from a representative of the Church of England about its desire to give a higher profile to science in the/their church. Whatever. And I also was bemused by a news article on the difficulty to build a genetic map of Australia Aboriginals due to cultural reticence of Aboriginals to the use of body parts from their communities in genetic research. While I understand and agree with the concept of data privacy, so that to restrain to expose personal information, it is much less clear [to me] why data collected a century ago should come under such protections if it does not create a risk of exposing living individuals. It reminded me of this earlier Nature news article about North-America Aboriginals claiming right to a 8,000 year old skeleton. On a more positive side, this news part also mentioned the first catalogue produced by the Gaia European Space Agency project, from the publication of more than a billion star positions to the open access nature of the database, in that the Gaia team had hardly any prior access to such wealth of data. A special issue part of the journal was dedicated to the impact of social inequalities in the production of (future) scientists, but this sounds rather shallow, at least at the level of the few pages produced on the topic and it did not mention a comparison with other areas of society, where they are also most obviously at work!

Only in Britain…

Posted in Kids, pictures, Travel, University life with tags , , , , , on October 15, 2016 by xi'an

A recent announcement on the University of Warwick official website:

Today the Minister for the Constitution, Chris Skidmore, presented WMG, at the University of Warwick, with a Royal Warrant signed by Her Majesty the Queen, officially conferring her Majesty’s recognition with the title of the Regius Professor of Manufacturing (Engineering).

The title of Regius Professorship is a rare and prestigious award given by Her Majesty the Queen to recognise exceptionally high quality research at an institution. The University of Warwick was one of 12 universities honoured to mark Her Majesty’s 90th Birthday. Previous to this, only 14 had been granted since the reign of Queen Victoria. It is believed that the first Regius Professorship was conferred to Aberdeen University in 1497 by King James IV.