Stability of classification trees

December 9, 2011
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Stability of classification trees

Classification trees are known to be unstable with respect to training data. Recently I have read an article on stability of classification trees by Briand et al. (2009). They propose a quantitative similarity measure between two trees. The method is i...

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Running your R and LaTeX Infrastructure from a portable USB Drive

December 9, 2011
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Running your R and LaTeX Infrastructure from a portable USB Drive

On my road to eventually running all of my programs off an USB device I’ve gotten a little bit closer yesterday thanks to input from Duncan Murdoch and Yihui Xie. Eventually running the entire Windows OS off a USB drive would be nice (not talking about running it as a Virtual Machine, but to have … Continue reading...

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MCMC chain analysis and convergence diagnostics with coda in R

December 9, 2011
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MCMC chain analysis and convergence diagnostics with coda in R

Last week, I gave a seminar about MCMC chain analysis and convergence diagnostics with coda in R, and I thought a summary would make a nice post. As a prerequisite, we will use a few lines of code, very similar to a previous post on MCMC sampling. In the code, we create some test data…

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RInside 0.2.5

December 8, 2011
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RInside 0.2.5 arrived on CRAN earlier today. RInside is a set of convenience classes which facilitate embedding of R inside of C++ applications and programs, using the classes and functions provided by the Rcpp R and C++ integration package. The ...

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Simple and Profitable

December 8, 2011
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Simple and Profitable

The end of the month effect was examined by MarketSci in the The Last Day of the Month Blahs post. The idea is simple: buy on the last day of the month and sell a few days later. This idea was put into a strategy by Quanting Dutchman in the Strategy 2 – Monthly End-of-the-Month

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Forbes: Big Data needs to earn its keep

December 8, 2011
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Dan Woods at Forbes makes a salient point about Big Data: it's not good enough merely to spend a ton of money to collect and store data -- it needs to earn its keep via data analysis: Let’s say you buy a huge Hadoop cluster along with Revolution Analytics, a productization of the R language that has been adapted...

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Le Monde puzzle [#752]

December 8, 2011
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Le Monde puzzle [#752]

After a loooong break, here is one Le Monde mathematical puzzle I had time to look at, prior to going to Dauphine for a Saturday morning class (in replacement of my R class this week)! The question is as follows: A set of numbers {1,…,N} is such that multiples of 4 are tagged C and

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Code Optimization: One R Problem, Thirteen Solutions – Now Sixteen!

December 8, 2011
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Code Optimization: One R Problem, Thirteen Solutions – Now Sixteen!

Introduction The old r-wiki optimisation challenge describes a string generation problem which I have bloged about previously both here and here. The Objective To code the most efficient algorithm, using R, to produce a sequence of strings based on a single integer input, e.g.: Solutions One Through Thirteen A variety of different approaches are illustrated on the

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RNA-Seq & ChiP-Seq Data Analysis Course at EBI

December 8, 2011
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I just got this announcement from EMBL-EBI about an RNA-seq/ChIP-seq analysis hands-on course. Find the full details, schedule, and speaker list here.Title: Advanced RNA-Seq and Chip-Seq Data Analysis Course Date: May 1-4 2012 Venue: EMBL-EBI, Hinxton,...

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Some example graphs in corrplot 0.60

December 8, 2011
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corrplot 0.60 is on CRAN now, here are some example graphs:

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Statistics with R – Lots of R Examples

December 8, 2011
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Statistics with R – Lots of R Examples

“Statistics with R” is a great R graphics & stats website. It provides lots of R examples, covering many analytics topics. It is also available as a PDF document to download at the website, as well as the R codes. … Continue reading →

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AGU Fall Meeting Day 2

December 8, 2011
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AGU Fall Meeting Day 2

One of the problems of trying to blog a conference when you are going to session talks and socialising in the evening is keeping up to date with your blogging. Day 2 was a little slower in regard to...

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Rcpp talk at Seattle RUG

December 7, 2011
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Thanks to Zach and the Seattle R User Group for the invitation. Earlier this evening I gave a talk about R, C++ and our Rcpp package, focussing on the why, how, what, who, and "one more thing" higher-level aspects of extending R. This was supposed to...

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Plotting BeijingAir Data

December 7, 2011
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Plotting BeijingAir Data

Here’s a bit of R code for scraping the BejingAir Twitter feed and plotting the hourly PM2.5 values for the past 24 hours. The script defaults to the past 24 hours but you can modify that by simply changing the value for the variable ‘n’.  You c...

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RcppArmadillo 0.2.33

December 7, 2011
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Conrad Sanderson made a first 2.4.1 bug fix release of Armadillo. We now have RcppArmadillo release 0.2.33 on CRAN which contains it. earlier today. The NEWS entry below summarises the changes. 0.2.33 2011-12-07 o Upgraded to Armadillo re...

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Using R — Easier Error Handling with try()

December 7, 2011
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In a previous post we looked at error handling in R with the tryCatch() function and how this could be used to write Java style try-catch-finally blocks. This time we’ll look at what can be done with the try() function …   read mo...

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Martyn Plummer’s Secret JAGS Blog

December 7, 2011
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Martyn Plummer, the creator of the open-source, C++, graphical-model compiler JAGS (aka “Just Another Gibbs Sampler”), runs a forum on the JAGS site that has a very similar feel to the mail-bag posts on this blog. Martyn answers general statistical computing questions (e.g., why slice sampling rather than Metropolis-Hastings?) and general modeling (e.g., why won’t The post Martyn...

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Movement around the mean "Stationary" OR "Unit root"

December 7, 2011
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Movement around the mean "Stationary" OR "Unit root"

The idea of modelling the time series of GNP, and other macroeconomic variables, data for US as a trend stationary (TS) process was brought into question by Nelson and Plosser in their groundbreaking research paper in 1982. Their re...

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Subscriptions Feature Added

December 7, 2011
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Subscriptions Feature Added

You can now subscribe to almost any content on the ProgrammingR website, including the job listings. To be notified of job listings as soon as they are posted, click the “R Jobs” link above and follow the instructions on that page to add the jobs feed to your feed reader.Because of this change, I will The post Subscriptions...

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Subscriptions Feature Added

December 7, 2011
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You can now subscribe to almost any content on the ProgrammingR website, including the job listings. By subscribing, you will receive email updates when new jobs are listed or when other content types you are following are posted or updated. To subscri...

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A pre-requisite to be a Data Scientist

December 7, 2011
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So what should be in the toolkit of people who call themselves a data scientist?A fundamental skill is the ability to manipulate data. A data scientist should be familiar and comfortable with a number of platforms and scripting tools to get the job don...

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A Spatial Data Analysis GUI for R

December 7, 2011
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I am excited to announce the addition of DeducerSpatial to the Deducer plug-in ecosystem. DeducerSpatial is a graphical user interface for the visualization and analysis of spatial data, built on Deducer's plug-in platform. In a previous post I illustrated how to user DeducerSpatial from the command line to add Open Street Map images to your

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Installing Rcpp on Windows 7 for R and C++ integration

December 7, 2011
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Installing Rcpp on Windows 7 for R and C++ integration

Introduction Romain Francois presented an Rcpp solution on his blog to an old r-wiki optimisation challenge which I had also presented R solutions for previously on my blog. The Rcpp package provides a method for integrating R and C++. This allows for faster execution of an R project by recoding the slower R parts into C+ and thus providing potential performance enhancements.

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New CRAN mirror from Revolution Analytics

December 7, 2011
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There's a new CRAN mirror available: cran.revolutionanalytics.com. It's provided by Revolution Analytics and hosted at Rackspace's high-availability data center in Dallas, TX. Especially for R users located in the western US, using this mirror will provide high-bandwidth access to open-source R downloads and CRAN packages while taking the load off of the main cran.r-project.org server. The mirror is updated...

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A Word Cloud with Spatial Meaning

December 7, 2011
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A Word Cloud with Spatial Meaning

..Some time ago I did a word cloud for representing a Google Scholar search result. Tal Galili pointed me at a post by Drew Conway that expanded on the topic of word clouds lacking spatial meaning. In fact the spatial ordering of words in a word cloud ...

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UseR! 2011 slides are now available

December 7, 2011
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I have just realized that UseR! 2011 presentation slides are now available from the conference web site.Unfortunately, no big surprise this year. Or maybe this is good news as it means that I have all the important stuff in my RSS Reader. And by the way, this blog is now listed on www.r-bloggers.com.To be fair there was...

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Principal Components Analysis with "R" (Part: 001)

December 7, 2011
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Principal Components Analysis with "R" (Part: 001)

This is the first "post" of my new adventure with a software that I consider very interesting and that give to people the oportunity to work with Chemometrics ("R" is free).To follow these examples, yo can download the following article:"Multivariate S...

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R is not C

December 7, 2011
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I keep trying to write R code like it was C code. It is a habit I’m trying to break myself of. For example, the other day I need to construct a model matrix of 1′s and 0′s in the … Continue reading →

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Call for Proposals for The R Series from Chapman & Hall/CRC

December 7, 2011
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(This is a guest post based on Calver, Rob e-mail to the R-help mailing list) We are delighted to announce that our new series of books on R is up and running, with two books already published and another nine forthcoming (including three set to publish in 2012). We are keen to receive proposals for books covering all aspects of...

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