An infographics entry in the New York Times about the distribution of a commute between two arbitrary subway stations in New York City, including a comparison of the distribution of a similar (?) commute by Tube in London. Showing that in most cases, the tail is thinner in London than in New York City. (Warning: […]

# Category: Books

## R Books Discount!

We, the community of Manning R and data science authors, have talked Manning into offering a catalog-wide 40% discount on all books. Please take a look at some great deals on some great technical books here: http://mng.bz/adRj !

## Gibbs sampling with incompatible conditionals

An interesting question (with no clear motivation) on X validated wondering why a Gibbs sampler produces NAs… Interesting because multi-layered: The attached R code indeed produces NAs because it calls the Negative Binomial Neg(x¹,p) random generator with a zero success parameter, x¹=0, which automatically returns NAs. This can be escaped by returning a one (1) […]

## down with Galton (and Pearson and Fisher…)

In the last issue of Significance, which I read in Warwick prior to the conference, there is a most interesting article on Galton’s eugenics, his heritage at University College London (UCL), and the overall trouble with honouring prominent figures of the past with memorials like named building or lectures… The starting point of this debate […]

## the grey bastards [book review]

Another almost random read, The Grey Bastards by Jonathan French is a light (if gritty) fantasy book that should appeal to Warhammer players. Including the use of hogs as mounts. In that the main characters are half-orcs, in a Universe where lots of species (also found in Warhammer) co-exist, if not peacefully. The idea of […]

## a hatchet job [book review]

By happenstance, I came across a rather savage review of John Hartigan’s Bayes Theory (1984) written by Bruce Hill in HASA, including the following slivers: “By and large this book is at its best in developing the mathematical consequences of the theory and at its worst when dealing with the underlying ideas and concepts, which […]

## Nature snapshots

In this 6 June issue of Nature, which I read on my way to O’Bayes, an editorial on the scary move by the WHO to incorporate traditional Chinese medicine remedies in its classification as this includes drugs made from protected and endangered species and as such remedies have not been evidence tested. A news brief […]

## The Long, Cruel History of the Anti-Abortion Crusade [reposted]

[Excerpts from an editorial in the NYT of John Irving, American author of the Cider House Rules novel we enjoyed reading 30 years ago] “(…) I respect your personal reasons not to have an abortion — no one is forcing you to have one. I respect your choice. I’m pro-choice — often called pro-abortion by […]

## natural LaTeX

Nature must have been out of inspiration in the past weeks for running a two-page article on LaTeX [as the toolbox column] and how it compares with… Word! Which is not so obvious since most articles in Nature are not involving equations (much) and are from fields where Word prevails. Besides the long-running whine that […]

## a non-riddle

Unless I missed a point in the last riddle from the Riddler, there is very little to say about it: Given N ocre balls, N aquamarine balls, and two urns, what is the optimal way to allocate the balls to the urns towards drawing an ocre ball with no urn being empty? Both my reasoning […]

## the most probable cluster

In the last issue of Bayesian Analysis, Lukasz Rajkowski studies the most likely (MAP) cluster associated with the Dirichlet process mixture model. Reminding me that most Bayesian estimates of the number of clusters are not consistent (when the sample size grows to infinity). I am always puzzled by this problem, as estimating the number of […]

## Le Monde puzzle [#1106]

A linear equation as Le Monde mathematical puzzle:

Find the ten integers x¹,x²,…. such that Ax=3x-1 where

Which returns 38 44 31 38 44 49 16 16 31 27 as its solution and is definitely of limited appeal…

## a generalized representation of Bayesian inference.

Jeremias Knoblauch, Jack Jewson and Theodoros Damoulas, all affiliated with Warwick (hence a potentially biased reading!), arXived a paper on loss-based Bayesian inference that Jack discussed with me on my last visit to Warwick. As I was somewhat scared by the 61 pages, of which the 8 first pages are in NeurIPS style. The authors […]

## O’Bayes 19/4

Last talks of the conference! With Rui Paulo (along with Gonzalo Garcia-Donato) considering the special case of factors when doing variable selection. Which is an interesting question that I had never considered, as at best I would remove all leves or keeping them all. Except that there may be misspecification in the factors as for […]

## O’Bayes 19/3.5

Among the posters at the second poster session yesterday night, one by Judith ter Schure visually standing out by following the #betterposter design suggested by Mike Morrison a few months ago. Design on which I have ambivalent feelings. On the one hand, reducing the material on a poster is generally a good idea as […]

## O’Bayes 19/3

Nancy Reid gave the first talk of the [Canada] day, in an impressive comparison of all approaches in statistics that involve a distribution of sorts on the parameter, connected with the presentation she gave at BFF4 in Harvard two years ago, including safe Bayes options this time. This was related to several (most?) of the […]

## O’Bayes 19/2

One talk on Day 2 of O’Bayes 2019 was by Ryan Martin on data dependent priors (or “priors”). Which I have already discussed in this blog. Including the notion of a Gibbs posterior about quantities that “are not always defined through a model” [which is debatable if one sees it like part of a semi-parametric […]

## O’Bayes 19/1 [snapshots]

Although the tutorials of O’Bayes 2019 of yesterday were poorly attended, albeit them being great entries into objective Bayesian model choice, recent advances in MCMC methodology, and the multiple layers of BART, for which I have to blame myself for sticking the beginning of O’Bayes too closely to the end of BNP as only the […]

## O’Bayes 19/1 [snapshots]

Although the tutorials of O’Bayes 2019 of yesterday were poorly attended, albeit them being great entries into objective Bayesian model choice, recent advances in MCMC methodology, and the multiple layers of BART, for which I have to blame myself for sticking the beginning of O’Bayes too closely to the end of BNP as only the […]

## running after my plane

A bit of a hectic trip to Abidjan last Sunday, starting from Caen in the early morning where I was supporting my daughter, wife, mother, and mother-in-law for the annual Rochambelle women-only 5k race on the previous evening! With my daughter managing a fantastic 52nd position and ending up first of her category! As I […]