From his presentation at the Greater Boston useR Group[*], R user Jeffrey Breen has shared some useful slides detailing how to bring data from relational databases like MySQL and Oracle. In fact, data from just about any relational database is accessible from R by sending an SQL query to the ... [Read more...]

Inspired by the Facebook Social Network chart, FlowingData's Nathan Yau also turns to R to create a beautiful chart of the network of all flight connections between major airlines in the US: Like the Facebook chart, the chart reflects the intensity of the connections (here, the number of flights) between ... [Read more...]

A lot of weird facts (?) can be found on the internet. For instance, about the height of the winner of Presidential elections in the US: the taller always win... "Still, being short does, on average, hurt a person's prospects...The tall guy gets th... [Read more...]

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Data Scientist Antonio Piccolboni recently published this comparison of the various language and interfaces available for programming Big Data analysis tasks in the map-reduce framework. The interfaces he reviewed included: Java Hadoop (mature and efficient, but verbose and difficult to program) Cascading (brings an SQL-like flavor to Java programming with ... [Read more...]

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We're having problem with starting values in glm(). A very simple logistic regression with just an intercept with a very simple starting value (beta=5) blows up.... [Read more...]

We come closer to a definitive answer on the relative merit of Ledoit-Wolf shrinkage versus a statistical factor model for variance matrices. Previously This post builds on the post entitled: A test of Ledoit-Wolf versus a factor model That post depended on some posts previous to it. New information Previously ... [Read more...]

Julien just signaled an intermitent disappearance of the posts on the ‘Og, depending on the operating system: Ubuntu 10.10 seems to be working (most of the time!) while Mac and Windows are having problems… This is beyond my abilities, I have contacted WordPress support, maybe they are working on some new ... [Read more...]

Over at R community site inside-R.org, Revolution's Joseph Rickert has published a How-To guide with tips for new users on How to Learn R, with links to resources for R books, blogs and courses. Check it out at the link below. Inside-R: How to Learn R [Read more...]

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 ... [Read more...]

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I’m starting on my real R-Scripts now. We got an assesment for some Reports and they needed my graphs and Veerle’s Reports. So the tasks are: Well distribution plot Quality plate control Surface Plot Heatmap CirclePlot and more to come&#823... [Read more...]

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My son would be extremely proud if I tell him I can spend hours building robots. Well, my robots are not as fancy as Dr Tenma's, but they usually do what I ask them to do. For instance, it is extremely simple to build a robot with R, to extract ... [Read more...]

In this post, I’m going to go over some basics of using conditionals and loops in R. I’ll expand on the example I use here in future posts. The conditionals and loops will be used to create some dummy eye movement data. Background Before I get into the ... [Read more...]

The March 2011 issue of JASA contains a review of Introducing Monte Carlo Methods with R by Hedibert Lopes. As in the previous review, the poor quality of the figures is (rightly) pointed out by Hedie. However, the main message of the review remains very positive and, furthermore, Hedie advertises the ‘... [Read more...]

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