## wrong algebra for slice sampler

Posted in Books, Kids, R, Statistics with tags , , , , , , , , , , , , on January 27, 2021 by xi'an

Once more, and thrice alas!, I became aware of a typo in our “Use R!” book through a question on X validated from a reader unable to reproduce the slice of a basic 2D slice sampler for a logistic regression with coefficients (a,b). Indeed, our slice reads as the incorrect set (missing the i=1,…,n)

$\left\{ (a,b): y_i(a+bx_i) > \log \frac{u_i}{1-u_i} \right\}$

when it should have been

$\bigcap_{i=1} \left\{ (a,b)\,:\ (-1)^{y_i}(a+bx_i) > \log\frac{u_i}{1-u_i} \right\}$

which is the version I found in my LaTeX file. So I do not know what happened (unless I corrected the LaTeX file at a later date and cannot remember it, but the latest chance on the file reads October 2011…). Fortunately, the resulting slices in a and b and the following R code remain correct. Unfortunately, both French and Japanese translations reproduce the mistake…

## oops…!

Posted in Statistics with tags , , , , , , , , , , on September 22, 2020 by xi'an

## a most inappropriate typo!

Posted in Statistics with tags , , , on March 29, 2020 by xi'an

## mea culpa!

Posted in Books, Kids, R, Statistics, University life with tags , , , , , , on October 9, 2017 by xi'an

An entry about our Bayesian Essentials book on X validated alerted me to a typo in the derivation of the Gaussian posterior..! When deriving the posterior (which was left as an exercise in the Bayesian Core), I just forgot the term expressing the divergence between the prior mean and the sample mean. Mea culpa!!!

## Statistical modeling and computation [apologies]

Posted in Books, R, Statistics, University life with tags , , , , , , , , , , , on June 11, 2014 by xi'an

In my book review of the recent book by Dirk Kroese and Joshua Chan,  Statistical Modeling and Computation, I mistakenly and persistently typed the name of the second author as Joshua Chen. This typo alas made it to the printed and on-line versions of the subsequent CHANCE 27(2) column. I am thus very much sorry for this mistake of mine and most sincerely apologise to the authors. Indeed, it always annoys me to have my name mistyped (usually as Roberts!) in references.  [If nothing else, this typo signals it is high time for a change of my prescription glasses.]