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Mapping the Chicago Democratic Mayoral 2011 primary with Ruby, R, and ggplot2 [Read more...]

Responding to yesterday's post which included an aside on using parallel processing for by-group computations in R, reader Christian Gunning mused about the possibility of using doSNOW on his network, with OpenSSH to manage the authentication: I sit on a fast campus network and have at least 10 remote cores available ... [Read more...]

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I just threw a post up on Revolutions, which got a lot longer than I planned. And got me thinking. And reading (see refs in previous post). And trying. Turns out that it was way easier than I thought! The problem:From the blog post: " OpenSSH is now available on ... [Read more...]

The Shared-Memory between multiple R sessions mentioned in my previous post got me thinking … quite some potential indeed. As a result, I investigated further using (calling) multiple R sessions from the same MT4 script. Specifically, I wanted to have a clearer understanding of the time required to performed lightning fast & ... [Read more...]

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Today, at lunch, Matthieu told us a nice story (or call it a paradox if you like) about the probability to find you seat empty when you get in a place.  a plane full of nuns Assume that you are in the line to get in the airplane, you are ... [Read more...]

Analyst and BI expert Steve Miller takes a look at the facilities in R for doing "by-group" processing of data. The task consisted of: ... read several text files, merge the results, reshape the intermediate data, calculate some new variables, take care of missing values, attend to meta data, execute a ... [Read more...]

I recently analyzed some data trying to find a model that would explain body fat distribution as predicted by several blood biomarkers. I had more predictors than samples (p__n), and I didn't have a clue which variables, interactions, or quadratic terms made biological sense to put into a model. ... [Read more...]

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The 0.9.2 release of Rcpp is now on CRAN and Debian. This version contains a build fix for the older 10.5.* version of OS X and its g++ 4.2.1 compiler; we now skip one test that upset it. CRAN builds for OS X should resume. We also added simple ... [Read more...]

Recently I was asked by O’Reilly publishing to give a book review for Paul Teetor new introductory book to R.  After giving the book some attention and appreciating it’s delivery of the material, I was happy to write and post this review.  Also, I’m very happy to ... [Read more...]

type n graph.R Download this file One of the most useful graphs you can produce in R using the plot(...) function is one with nothing in it. Using the type="n" option, you get a blank canvas to which you can add points, lines, text, sh... [Read more...]

Andrew Ng has posted introductory machine learning lessons on the OpenClassRoom site. I've watched the first set and will here solve Exercise 2. The exercise is to build a linear regression implementation, I'll use R. The point of linear regression is to come up with a mathematical function(model) that represents ... [Read more...]

The Web-based Flash game Canabalt, whose scores have been analyzed by R before, is now available as an iOS App. Because the app is configured to work on three different platforms: the iPad, iPhone and iPod Touch; and because players are invited to tweet their best scores at the end ... [Read more...]

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From the HRSA website: [The ARF 2009] is a database containing more than 6,000 variables for each of the nation’s counties. ARF contains information on health facilities, health professions, measures of resource scarcity, health status, economic activity, health training programs, and socioeconomic and environmental characteristics. The data file itself is formatted ... [Read more...]

A bug-fix release RQuantLib 0.3.6 is now on CRAN and in Debian. RQuantLib combines (some of) the quantitative analytics of QuantLib with the R statistical computing environment and language. There are only two changes to two files where an explic... [Read more...]

Thanks to some help from Pierre Roudier, the aqp package now has some new S4-style classes and methods-- custom tailored to the complexities of soil profile data. These new classes/methods are only available in the aqp development branch, found on our ... [Read more...]