Publications by xi'an

Typo in Example 3.6

16.09.2010

Edward Kao pointed out the following difficulty about Example 3.6 in Chapter 3 of “Introducing Monte Carlo Methods with R”: I have two questions that have puzzled me for a while. I hope you can shed some lights. They are all about Example 3.6 of your book. 1. On page 74, there is a term x(1-x) for m(x). This is fine. But the term disappe...

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R tee-shirt

21.09.2010

I gave my introduction to the R course in a crammed amphitheatre of about 200 students today. Had to wear my collectoR teeshirt from Revolution Analytics, even though it only made the kids pay attention for about 30 seconds… The other few “lines” that worked were using the Proctor & Gamble “car 54″ poster and calling bootstrap “Statis...

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Monte Carlo Statistical Methods third edition

23.09.2010

Last week, George Casella and I worked around the clock on starting the third edition of Monte Carlo Statistical Methods by detailing the changes to make and designing the new table of contents. The new edition will not see a revolution in the presentation of the material but rather a more mature perspective on what matters most in statistical si...

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Effective sample size

23.09.2010

In the previous days I have received several emails asking for clarification of the effective sample size derivation in “Introducing Monte Carlo Methods with R” (Section 4.4, pp. 98-100). Formula (4.3) gives the Monte Carlo estimate of the variance of a self-normalised importance sampling estimator (note the change from the original version i...

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Riemann, Langevin & Hamilton [reply]

27.09.2010

Here is a (prompt!) reply from Mark Girolami corresponding to the earlier post: In preparation for the Read Paper session next month at the RSS, our research group at CREST has collectively read the Girolami and Calderhead paper on Riemann manifold Langevin and Hamiltonian Monte Carlo methods and I hope we will again produce a joint arXiv preprin...

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Galton & simulation

27.09.2010

Stephen Stigler has written a paper in the Journal of the Royal Statistical Society Series A on Francis Galton’s analysis of (his cousin) Charles Darwin’ Origin of Species, leading to nothing less than Bayesian analysis and accept-reject algorithms! “On September 10th, 1885, Francis Galton ushered in a new era of Statistical Enlightenment...

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Le Monde puzzle [38]

29.09.2010

Since I have resumed my R class, I will restart my resolution of Le Monde mathematical puzzles…as they make good exercises for the class. The puzzle this week is not that exciting: Find the four non-zero different digits a,b,c,d such that abcd is equal to the sum of all two digit numbers made by picking without replacement two digits from {a,b...

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Typo in Example 5.18

02.10.2010

Edward Kao pointed out several typos in Example 5.18 of Monte Carlo Statistical Methods. First, the customers in area i should be double-indexed, i.e. which implies in turn that . Then the summary T should be defined as and as given that the first m customers have the fifth plan missing. Filed under: Books, R, Statistics, University life Tagg...

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Le Monde puzzle [34]

03.10.2010

Since the puzzle in this week (-end) edition of Le Monde is not (easily) solvable via an R program, I chose to go back to an older puzzle that my students can solve. Eleven [distinguishable] token are [arbitrarily] distributed around a 200 meter perimeter-long ring. They all start moving at the same speed, 18km/h, in arbitrary directions. When tw...

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Typos…

05.10.2010

Edward Kao just sent another typo found both in  Monte Carlo Statistical Methods (Problem 3.21) and in Introducing Monte Carlo Methods with R (Exercise 3.17), namely that should be I also got another email from Jerry Sin mentioning that matrix summation in the matrix commands of Figure 1.2 of Introducing Monte Carlo Methods with R should be m...

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