Publications by Julyan Arbel

Artist view of crimes in London

10.10.2011

At first sight, one could think this picture is a scale model of some narrow moutains, like Bryce Canyon… Actually it represents crimes in East London, an cardboard artwork by the Londoner artist Abigail Reynolds, called Mount Fear.  Here is what can be read on the artist’s webpage: The terrain of Mount Fear is generated by data sets relatin...

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Random art on the web

15.10.2011

Since we explored some statitics of an abstract painting with Pierre (we even have an article in Variances last issue!), I became more sensitive to art linked to randomness. Here are some pointers to related websites I have digged out. Random.org, mentioned here by Pierre, is, at it reads, a true random number service that generates randomness vi...

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Power-laws: choose your x and y variables carefully

16.11.2011

This is a follow-up of the post Power of running world records As suggested by Andrew, plotting running world records could benefit from a change of variables. More exactly the use of different variables sheds light on a [now] well-known [to me] sports result provided in a 2000 Nature paper by Sandra Savaglio and Vincenzo Carbone (thanks Ken): th...

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Create maps with maptools R package

13.12.2011

Baptiste Coulmont explains on his blog how to use the R package maptools. It is based on shapefile files, for example the ones offered by the French geography agency IGN (at départements and communes level). Some additional material like roads and railways are provided by the OpenStreetMap project, here. For the above map, you need to dowload an...

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Psycho dice and Monte Carlo

16.12.2011

Following Pierre’s post on psycho dice, I want here to see by which average margin repeated plays might be called influenced by mind will. The rules are the following (exerpt from the novel Midnight in the Garden of Good and Evil, by John Berendt): You take four dice and call out four numbers between one and six–for example, a four, a three, ...

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Coming R meetings in Paris

04.02.2012

If you live in Paris and are interested in R, there will be two meetings for you this week. First a Semin-R session, organized at the Muséum National d’Histoire Naturelle on Tuesday 7 Feb (too bad, the Museum is closed on Tuesdays). Presentations will be about colors, phylogenies and maps, while I will speak about (my beloved) RStudio. The sli...

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Daily casualties in Syria

09.02.2012

Every new day brings its statistics of new deaths in Syria… Here is an attempt to learn about the Syrian uprising by the figures. Data vary among sources: the Syrian opposition provides the number of casualties by day (here on Dropbox), updated on 8 February 2012, with a total exceeding 8 000. We note first that the attacks accelerate, as the c...

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Next R meeting in Paris INSEE: ggplot2 and parallel computing

12.06.2012

Hi, our group of R users from INSEE, aka FLR, meets monthly in Paris. Next meeting is on Wed 13 (tomorrow), 1-2 pm, room 539 (an ID is needed to come in,  map to access INSEE R), about ggplot2 and parallel computing. Since the first meeting in February, presentations have included hot topics like webscrapping, C in R, RStudio, SQLite databa...

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Using R in LaTeX with knitr and RStudio

28.02.2013

Hi, I presented today at INSEE R user group (FLR) how to use knitr (Sweave evolution) for writing documents which are self contained with respect to the source code: your data changed? No big deal, just compile your .Rnw file again and you are done with an updated version of your paper![Ctrl+Shift+I] is easy. Some benefits with respect to having...

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momentify R package

19.09.2014

I presented today an arxived paper of my postdoc at the big success Young Bayesian Conference in Vienna. The big picture of the talk is simple: there are situations in Bayesian nonparametrics where you don’t know how to sample from the posterior distribution, but you can only compute posterior expectations (so-called marginal methods). So e....

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