2034 search results for "Twitter"

Le Monde puzzle [48]

December 1, 2010
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Le Monde puzzle [48]

This week(end), the Le Monde puzzle can be (re)written as follows (even though it is presented as a graph problem): Given a square 327×327 symmetric matrix A, where each non-diagonal entry is in {1,2,3,4,5} and , does there exist a triplet (i,j,k) such that Solving this problem in R is very easy. We can create

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Top 10 things that suck about Sweave

December 1, 2010
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Top 10 things that suck about Sweave

People rave about Sweave and the literate programing paradigm and I am guilty as charged. I speak Sweave, I think Sweave, I dream Sweave. As a matter of fact my default mode of operation is Sweave and anything else is an … Continue reading →

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how to install 64-bit rggobi on Mac OS X 10.5

November 30, 2010
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how to install 64-bit rggobi on Mac OS X 10.5

rggobi is the first package which didn't survive my transition from 32-bit to 64-bit in R 2.11.1. Fortunately, installing the package from source fixes it, and Hadley Wickham has posted the prerequisites and procedure.

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Analysis of retractions in PubMed

November 30, 2010
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Analysis of retractions in PubMed

As so often happens these days, a brief post at FriendFeed got me thinking about data analysis. Entitled “So how many retractions are there every year, anyway?”, the post links to this article at Retraction Watch. It discusses ways to estimate the number of retractions and in particular, a recent article in the Journal of

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Slices and crumbs [arXiv:1011.4722]

November 29, 2010
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Slices and crumbs [arXiv:1011.4722]

An interesting note was arXived a few days ago by Madeleine Thompson and Radford Neal. Beside the nice touch of mixing crumbs and slices, the neat idea is to have multiple-try proposals for simulating within a slice and to decrease the dimension of the simulation space at each try. This dimension diminution is achieved via

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Joy of Stats coming soon

November 29, 2010
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Joy of Stats coming soon

The Joy of Stats really is a joy.  It will be shown on BBC4, apparently scheduled for December 7.  (That date comes from Hans Rosling on twitter, I haven’t found scheduling evidence at the BBC.) I saw its debut at the Royal Statistical Society on World Statistics Day. Here is a five minute excerpt: You … Continue reading...

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Computing evidence

November 28, 2010
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Computing evidence

The book Random effects and latent variable model selection, edited by David Dunson in 2008 as a Springer Lecture Note. contains several chapters dealing with evidence approximation in mixed effect models. (Incidentally, I would be interested in the story behind the  Lecture Note as I found no explanation in the backcover or in the preface.

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Random variable generation (Pt 1 of 3)

November 28, 2010
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Random variable generation (Pt 1 of 3)

As I mentioned in a recent post, I’ve just received a copy of Advanced Markov Chain Monte Carlo Methods. Chapter 1.4 in the book (very quickly) covers random variable generation. Inverse CDF Method A standard algorithm for generating random numbers is the inverse cdf method. The continuous version of the algorithm is as follows: 1.

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Computational efficiency of great-circle distance calculations in R

November 28, 2010
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Computational efficiency of great-circle distance calculations in R

An obvious omission in my previous post on Great-circle distance calculations in R was a lack of discussion on the computational efficiency of the various methods, and in particular comparing different implementations of the same method. One of the comments … Continue reading →

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Advanced Markov Chain Monte Carlo Methods (AMCMC)

November 27, 2010
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Advanced Markov Chain Monte Carlo Methods (AMCMC)

I’ve just received my copy of Advanced Markov Chain Monte Carlo Methods, by Liang, Liu, & Carroll. Although my PhD didn’t really involve any Bayesian methodology (and my undergrad was devoid of any Bayesian influence), I’ve found that the sort of problems I’m now tackling in systems biology demand a Bayesian/MCMC approach. There are a

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