Monthly Archives: September 2010

Classification Trees using the rpart function

September 21, 2010
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Classification Trees using the rpart function

In a previous post on classification trees we considered using the tree package to fit a classification tree to data divided into known classes. In this post we will look at the alternative function rpart that is available within the base R distribution. Fast Tube by Casper A classification tree can be fitted using the rpart function

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Example 8.6: Changing the reference category for categorical variables

September 21, 2010
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Example 8.6: Changing the reference category for categorical variables

How can we change the reference category for a categorical variable? This question comes up often in a consulting practice.When including categorical covariates in regression models, there is a question of how to incorporate the categories. One simpl...

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Install and load R package "Rcmdr" to quickly install lots of other packages

September 21, 2010
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I recently reformatted my laptop and needed to reinstall R and all the packages that I regularly use. In a previous post I covered R Commander, a nice GUI for R that includes a decent data editor and menus for graphics and basic statistical analysis. Since Rcmdr depends on many other packages, installing and loading Rcmdr like this...install.packages("Rcmdr", dependencies=TRUE)library(Rcmdr) ..

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R tee-shirt

September 21, 2010
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R tee-shirt

I gave my introduction to the R course in a crammed amphitheatre of about 200 students today. Had to wear my collectoR teeshirt from Revolution Analytics, even though it only made the kids pay attention for about 30 seconds… The other few “lines” that worked were using the Proctor & Gamble “car 54″ poster and

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AQP Examples: Profile Visualization

September 20, 2010
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Two examples of the output from the profile_plot() function, using data from the Sierra Foothill Region, CA. read more

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Auto-complete for R in EmEditor

September 20, 2010
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Auto-complete for R in EmEditor

This will work for any language you have a syntax file for, but I'll use R as the example.1. Open an R file, and on the plugins menu, click "Word Complete"2. Type a couple of letters e.g. rn and then press ctrl+space (default word suggest keyboard...

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Saptarshi Guha on Hadoop, R

September 20, 2010
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Saptarshi Guha (author of the Rhipe package) joins the likes of Ebay, Yahoo, Twitter and Facebook and as one of just 37 presenters at the Hadoop World conference. (Revolution Analytics is proud to sponsor Saptarshi's presence at this event, which take place in New York on October 12.) He'll be talking about using R and Hadoop to analyze Voice-over-IP...

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Problems with R

September 20, 2010
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Struggling for two whole days to do some not-terribly-advanced repeated-measures analysis of variance in R. Probably my worst experience with R so far and really an example of where R could do with some centralisation of effort. I have explored six or seven ways to do more or less the same thing, but each approach

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Problems with R

September 20, 2010
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Struggling for two whole days to do some not-terribly-advanced repeated-measures analysis of variance in R. Probably my worst experience with R so far and really an example of where R could do with some centralisation of effort. I have explo...

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In case you missed it: August Roundup

September 20, 2010
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In case you missed them, here are some articles from August of particular interest to R users. We noted that R had a key role in the US government's reaction to the BP oil spill, as related by the Statistical Engineering division chief at NIST. We linked to an example of creating an animation in Google Earth based on...

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