Publications by Julyan Arbel
Graph gallery in R
R is sometime criticized for producing graphs not as elaborated as Matlab ones, or other softwares’. Here is a link to a graph gallery by Romain François to “enhance your data visualization with R”. The corresponding R code is given. Might be useful for ENSAE students for ‘statap’ projects. Below are four examples. The maps package wil...
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Speed up your R code
This short post is to share an R tip Pierre recently gave me. When you need to store values sequentially (typically inside a loop), it’s more far efficient to create the whole vector (or matrix) and to fill it, rather than to concatenate the values to your current vector (or matrix). In terms of allocation time, it’s up to 60 times faster n=...
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Statisfaction on R-bloggers
This is the first post of Statisfaction on R-bloggers. As an introduction: we are PhD students and postdocs at CREST, a research centre on economics and statistics located in Paris, France. We jointly share tips and tricks useful in our everyday jobs, links to various pages, articles, conferences, seminars, including a PhD student seminar at CRES...
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RStudio is good for you
I was recently introduced to RStudio, a new integrated development environment for R, it is just amazing! It is free, and open, compatible with PC/Mac/Linux OSs. You can also choose to run it in the cloud, and access it from your favorite web browser. As you can see, the window divides into four in a customizable way. For the source code, multipl...
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Running R on an iPhone/iPad with RStudio
This thread has been widely discussed on a lot of forums. To make a long story short, running natively R on an iDevice (meaning iPhone/iPad) is disabled by its OS, unless it is jailbroken. The steps for the installation through Cydia are described in this R wiki, or this post. But there are some limitations, including bugs in package management. ...
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Wilcoxon Champagne test
As an appetizer for Paris triathlon, Jérôme and I ran as a team last week-end an adventure racing in Champagne region (it mainly consists in running, cycling, canoeing, with a flavor of orienteering, and Champagne is kept for the end). It was organized by Ecole Polytechnique students who, for the first time, divided Saturday’s legs in two par...
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Power of running world records
Followinga few entries on sports here and there, I was wondering what kind of law follow the running records with respect to the distance. The data are available on Wikipedia, or here for a tidied version. It collects 18 distances, from 100 meters to 100 kilometers. A log-log scale is in order: It is nice to find a clear power law: the relation ...
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Last and final on Richter’s painting
For a quick recap, Pierre and I supervised a team project at Ensae last year, on a statistical critique of the abstract painting 1024 Colours by painter Gerhard Richter. The four students, Clémence Bonniot, Anne Degrave, Guillaume Roussellet and Astrid Tricaud, did an outstanding job. Here is a selection of graphs and results they produced. 1. A...
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World Tourism Day, and Google Public Data Explore
Today is the World Tourism Day! So let’s speak about some tourism related datasets – and others. Among other nice functions, Google offers a Public Data Explore in a beta version which provides a collection of datasets from OECD, IMF, Eurostat, World Bank, US Census Bureau, etc (cf. our datasets page as well). It is possible to plot these da...
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Googling Bayes’ pictures
I am writing way too many posts in a row on Google tools. I promise I will think about something else soon. I find amusing the possibility to launch a search in Google images by just dragging a picture into the search box, instead of typing text. I remember that Pierre told me about it a long time ago, but this is the first time I play with it. F...
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