## The winds of Winter [Bayesian prediction]

Posted in Books, Kids, R, Statistics, University life with tags , , , , , , , , , , on October 7, 2014 by xi'an

A surprising entry on arXiv this morning: Richard Vale (from Christchurch, NZ) has posted a paper about the characters appearing in the yet hypothetical next volume of George R.R. Martin’s Song of ice and fire series, The winds of Winter [not even put for pre-sale on amazon!]. Using the previous five books in the series and the frequency of occurrence of characters’ point of view [each chapter being told as from the point of view of one single character], Vale proceeds to model the number of occurrences in a given book by a truncated Poisson model,

$x_{it} \sim \mathcal{P}(\lambda_i)\text{ if }|t-\beta_i|<\tau_i$

in order to account for [most] characters dying at some point in the series. All parameters are endowed with prior distributions, including the terrible “large” hyperpriors familiar to BUGS users… Despite the code being written in R by the author. The modelling does not use anything but the frequencies of the previous books, so knowledge that characters like Eddard Stark had died is not exploited. (Nonetheless, the prediction gives zero chapter to this character in the coming volumes.) Interestingly, a character who seemingly died at the end of the last book is still given a 60% probability of having at least one chapter in  The winds of Winter [no spoiler here, but many in the paper itself!]. As pointed out by the author, the model as such does not allow for prediction of new-character chapters, which remains likely given Martin’s storytelling style! Vale still predicts 11 new-character chapters, which seems high if considering the series should be over in two more books [and an unpredictable number of years!].

As an aside, this paper makes use of the truncnorm R package, which I did not know and which is based on John Geweke’s accept-reject algorithm for truncated normals that I (independently) proposed a few years later.

## hospital series

Posted in Statistics with tags , , , , , , , , , on May 5, 2013 by xi'an

While I usually never find enough time to watch series (or even less telly!), I took advantage of those three weeks at the hospital to catch up with Game of Thrones and discovered Sherlock, thanks to Judith. As I have been reading George Martin’s epics, A Song of Ice and Fire, from the very beginning in 1991, I was of course interested to see how those massive books with their intricate politics and complex family trees could be made into 50 minutes episodes. Glimpses caught from my son’s computer had had me looking forward to it. After watching the entire second season and the earlier episodes of the third season, I am quite impressed by both the rendering of the essentials of the book and the quality of the movies. It is indeed amazing that HBO invested so much into the series, with large scale battles and medieval cities and thousands of characters. The filming locations were also well-chosen: while I thought most of the northern scenes had been shot in Scotland, it actually appears that they mostly came from Ireland and Iceland (with incredible scenery like the one above beyond the Wall!).  The cast is not completely perfect, obviously, with both Jon Snow (Kit Harington) and Rob Stark (Richard Madden) being too shallow in my opinion and Daenerys (Emilia Clarke) lacking charisma, but most characters are well-rendered and the Lannisters are terrific, Tyrion (Peter Dinklage) being the top actor in my opinion (and Arya (Maisie Williams) coming second). I was also surprised by the popularity of the series at the hospital, as several nurses and doctors started discussing it with me…

Sherlock Holmes is a British series, set in contemporary London, and transposing some of Sherlock Holmes’ adventures in contemporary Britain. While I had not heard about this series previously, I was quite taken by it. It is quite innovative both in its scenario and its filming, it does not try to stick to the books, the dialogues are witty and the variety of accents quite pleasant (if hard to catch at times), and… Watson has a blog! It is also a pleasure to catch glimpses of London (Baker Street is actually Gower Street, near UCL) and the Hound of Baskerville takes place on Dartmoor.  I do not think I will continue watching those series once out of the hospital, but they were a pleasing distraction taking me far, far away from my hospital room for a few hours!

## A dance with dragons

Posted in Books with tags , , on October 29, 2011 by xi'an

A few weeks ago, I finished the fifth volume of George Martin, A Dance with Dragons, I had bought in Lancaster last summer but could not carry with me to the US (and onto the boat!). It reads wonderfully, just like the previous volumes, and so I wonder why it took the author so long to produce it. (He apologizes about this in the preface to the book. But does not [have to] provide reasons.) Esp. when considering that the story constitutes the “other side” of the previous volume, covering characters and regions that were omitted in the fourth book. Even though the pace is sometimes a wee slow (e.g., the coverage of Tyrion’s travel and mishaps and of his every thought!, or of Daenerys’ procrastination and hesitations), again, it is very pleasant to read. I am actually surprised at how easy it is to launch back into the complex geography and geopolitics of Martin’s universe, given the five year gap with my reading the previous volume. The important and consequential action has to wait a while, but things are moving fast by the end of the book, with surprising and permanent changes of dominance and of rulers. It is a good thing that Martin is eliminating some of his characters as it means he cannot go for ever in writing small prints about them! On another level, it is quite interesting to spot so many readers of the first volume (A Game of Thrones), in the metro and in airports, clearly generated by the TV adaptation on HBO…

## At last!

Posted in Books, Travel with tags , , , on July 25, 2011 by xi'an

While in Lancaster, I bought the latest volume in George Martin‘s Song of Ice and Fire series. A book I have been waiting for, for about six years… Even though the size of the series is far behind the Wheel of Time, it is clearly headed towards the same fate of never getting any near the finishing line, unless someone else takes over! I am very much surprised at the TV adaptation of the first volume, A Game of Thrones, nor because it is a poor adaptation (quite the opposite!), neither because it attracted many viewers (including my son), but because there is no end in sight. Or maybe that’s a good thing for a TV adaptation! In any case, I got the heavy hardcover in the Lancaster University bookstore at the price of a paperback. A  voluminous and hopefully good enough read for the incoming summer break!