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Together with my friend and former colleague Georgios Kaiafas, we formed a team to participate to the Athens Datathon 2015, organized by ThinkBiz on October 3; the datathon took place at the premises of Skroutz.gr, which was also the major sponsor and the data provider. It was the second such event ... [Read more...]

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Back in the mists of time, whilst programming early versions of Canoco, Cajo ter Braak decided to allow users to specify how species and site ordination scores were scaled relative to one another via a simple numeric coding system. This was fine for the DOS-based software that Canoco was at ... [Read more...]

I recently saw Slate.com redid its Mideast Graphic and thought it would be good to redo my previous analysis. From the original slate graphic it's hard to make much sense of what's happening and who's friends with whom.From the graph below we can ... [Read more...]

Update: Most of the data frame functions in purrr have been deprecated in favour of a new family of functions in dplyr. The intent is to better separate the responsibilities of packages in the tidyverse. First of all map() now always returns a list. It no longer preserves the data ... [Read more...]

purrr was finally released on CRAN last week. This package is focused on working with lists (and data frames by the same token). However it is not a DSL for lists in the way dplyr is a DSL for data frames. It aims at creating a "better standard lib" focused ... [Read more...]

This afternoon, Jean-Luc asked me some help about an old post I did publish, minuit, l’heure du crime; and some graphs published a few days after, where I used a different visualisation, in another post. The idea is that the hour can be seen as circular, in the sense ... [Read more...]

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In this repository hosted at github, the datadolph.in team is sharing all of the R codebase that it developed to analyze large quantities of data.datadolph.in team has benefited tremendously from fellow R bloggers and other open source communities and ... [Read more...]

In this repository hosted at github, the datadolph.in team is sharing all of the R codebase that it developed to analyze large quantities of data.datadolph.in team has benefited tremendously from fellow R bloggers and other open source communities and ... [Read more...]

I came across the butterfly curve, which was discovered by Temple Fay. The butterfly curve is produced by a parametric equation where: x = sin(t) * (e^cos(t)-2cos(λt)-sin(t/12)^5) and y = cos(t) * (e^cos(t)-2cos(λt)-sin(t/12)^5). Where t stands for time ... [Read more...]

by Andrie de Vries In one of John D. Cooke's blog posts of 2010 (Parameters and Percentiles), he poses the following problem: The doctor says 10% of patients respond within 30 days of treatment and 80% respond within 90 days of treatment. Now go turn that into a probability distribution. That’s a common task ... [Read more...]

I read Data Mining with Rattle and R by Graham Williams over a year ago. It's not a new book and I've just been tardy in writing up a review. That's not to say that I have not used the book in the interim: it's been on my desk at ... [Read more...]

For a conference in the R language, EARL London 2015 saw a surprising number of discussions about Python. I like to think that at least some of this was to do with the fact that the day before the conference, … Continue reading → [Read more...]

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I gave a seminar at Stanford today. Slides are below. It was definitely the most intimidating audience I’ve faced, with Jerome Friedman, Trevor Hastie, Brad Efron, Persi Diaconis, Susan Holmes, David Donoho and John Chambers all present (and probably other famous names I’ve missed). I’ll be giving ... [Read more...]

We have some strange data in cybersecurity. One of the (IMO) stranger data files is a Domain Name System (DNS) zone file. This file contains mappings between domain names and IP addresses (and other things) represented by “resource records”. Here’s an example for the dummy/example domain example.com: $... [Read more...]

We have some strange data in cybersecurity. One of the (IMO) stranger data files is a Domain Name System (DNS) zone file. This file contains mappings between domain names and IP addresses (and other things) represented by “resource records”. Here’s an example for the dummy/example domain example.com: $... [Read more...]