Archive for Amazon

oxwasp@amazon.de

Posted in Books, Kids, pictures, Running, Statistics, Travel, University life with tags , , , , , , , , , , , , , , , , , on April 12, 2017 by xi'an

The reason for my short visit to Berlin last week was an OxWaSP (Oxford and Warwick Statistics Program) workshop hosted by Amazon Berlin with talks between statistics and machine learning, plus posters from our second year students. While the workshop was quite intense, I enjoyed very much the atmosphere and the variety of talks there. (Just sorry that I left too early to enjoy the social programme at a local brewery, Brauhaus Lemke, and the natural history museum. But still managed nice runs east and west!) One thing I found most interesting (if obvious in retrospect) was the different focus of academic and production talks, where the later do not aim at a full generality or at a guaranteed improvement over the existing, provided the new methodology provides a gain in efficiency over the existing.

This connected nicely with me reading several Nature articles on quantum computing during that trip,  where researchers from Google predict commercial products appearing in the coming five years, even though the technology is far from perfect and the outcome qubit error prone. Among the examples they provided, quantum simulation (not meaning what I consider to be simulation!), quantum optimisation (as a way to overcome multimodality), and quantum sampling (targeting given probability distributions). I find the inclusion of the latest puzzling in that simulation (in that sense) shows very little tolerance for errors, especially systematic bias. It may be that specific quantum architectures can be designed for specific probability distributions, just like some are already conceived for optimisation. (It may even be the case that quantum solutions are (just next to) available for intractable constants as in Ising or Potts models!)

zurück nach Berlin [jatp]

Posted in Statistics with tags , , , , , on March 28, 2017 by xi'an

Pitman medal for Kerrie Mengersen

Posted in pictures, Statistics, Travel, University life with tags , , , , , , , , , , , , , on December 20, 2016 by xi'an

6831250-3x2-700x467My friend and co-author of many years, Kerrie Mengersen, just received the 2016 Pitman Medal, which is the prize of the Statistical Society of Australia. Congratulations to Kerrie for a well-deserved reward of her massive contributions to Australian, Bayesian, computational, modelling statistics, and to data science as a whole. (In case you wonder about the picture above, she has not yet lost the medal, but is instead looking for jaguars in the Amazon.)

This medal is named after EJG Pitman, Australian probabilist and statistician, whose name is attached to an estimator, a lemma, a measure of efficiency, a test, and a measure of comparison between estimators. His estimator is the best equivariant (or invariant) estimator, which can be expressed as a Bayes estimator under the relevant right Haar measure, despite having no Bayesian motivation to start with. His lemma is the Pitman-Koopman-Darmois lemma, which states that outside exponential families, sufficient is essentially useless (except for exotic distributions like the Uniform distributions). Darmois published the result first in 1935, but in French in the Comptes Rendus de l’Académie des Sciences. And the measure of comparison is Pitman nearness or closeness, on which I wrote a paper with my friends Gene Hwang and Bill Strawderman, paper that we thought was the final paper on the measure as it was pointing out several majors deficiencies with this concept. But the literature continued to grow after that..!

my book available for a mere $1,091.50

Posted in Books with tags , , , on May 1, 2016 by xi'an

As I was looking at a link to my Bayesian Choice book on Amazon, I found that one site offered it for the modest sum of $1,091.50, a very slight increase when compared with the reference price of $59.95… I do wonder at the reason (scam?) behind this offer as such a large price is unlikely to attract any potential buyer to the site. (Obviously, if you are interested by this price, feel free to contact me!)

Statistical rethinking [book review]

Posted in Books, Kids, R, Statistics, University life with tags , , , , , , , , , , , , , , , , , , , , , on April 6, 2016 by xi'an

Statistical Rethinking: A Bayesian Course with Examples in R and Stan is a new book by Richard McElreath that CRC Press sent me for review in CHANCE. While the book was already discussed on Andrew’s blog three months ago, and [rightly so!] enthusiastically recommended by Rasmus Bååth on Amazon, here are the reasons why I am quite impressed by Statistical Rethinking!

“Make no mistake: you will wreck Prague eventually.” (p.10)

While the book has a lot in common with Bayesian Data Analysis, from being in the same CRC series to adopting a pragmatic and weakly informative approach to Bayesian analysis, to supporting the use of STAN, it also nicely develops its own ecosystem and idiosyncrasies, with a noticeable Jaynesian bent. To start with, I like the highly personal style with clear attempts to make the concepts memorable for students by resorting to external concepts. The best example is the call to the myth of the golem in the first chapter, which McElreath uses as an warning for the use of statistical models (which almost are anagrams to golems!). Golems and models [and robots, another concept invented in Prague!] are man-made devices that strive to accomplish the goal set to them without heeding the consequences of their actions. This first chapter of Statistical Rethinking is setting the ground for the rest of the book and gets quite philosophical (albeit in a readable way!) as a result. In particular, there is a most coherent call against hypothesis testing, which by itself justifies the title of the book. Continue reading

Amazonish warning

Posted in Books, Kids, R, Statistics with tags , , , , , on March 11, 2016 by xi'an

As in previous years, I want to repost a warning to ‘Og readers that all http links to Amazon.com [and much more rarely to Amazon.fr] products found on this ‘Og are actually susceptible to reward me with an advertising percentage if a purchase is made by the reader in the 24 hours following the entry on Amazon through this link, thanks to the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com/fr. Here are some of the most Og-unrelated purchases, less exotic than in previous years (maybe because of a lower number of items):

Once again, books I reviewed, positively or negatively, were among the top purchases… Like a dozen Monte Carlo simulation and resampling methods for social science, half a dozen Statistics done wrong, and Think Bayes: Bayesian Statistics Made Simple [which also attracted a lot of visits when I reviewed it], and still a few copies of Naked Statistics (despite a most critical review.) Thanks to all readers activating those links and feeding further my book addiction, with the drawback of inducing even more book reviews on the ‘Og…

amazonish thanks (& repeated warning)

Posted in Books, Kids, R, Statistics with tags , , , , , on December 9, 2014 by xi'an

As in previous years, at about this time, I want to (re)warn unaware ‘Og readers that all links to Amazon.com and more rarely to Amazon.fr found on this blog are actually susceptible to earn me an advertising percentage if a purchase is made by the reader in the 24 hours following the entry on Amazon through this link, thanks to the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com/fr. Unlike last year, I did not benefit as much from the new edition of Andrew’s book, and the link he copied from my blog entry… Here are some of the most Og-unrelated purchases:

Once again, books I reviewed, positively or negatively, were among the top purchases… Like a dozen Monte Carlo simulation and resampling methods for social science , a few copies of Naked Statistics. And again a few of The Cartoon Introduction to Statistics. (Despite a most critical review.) Thanks to all of you using those links and feeding further my book addiction, with the drawback of inducing even more fantasy book reviews.