Monthly Archives: August 2011

How Google uses R to make online advertising more effective

August 3, 2011
By

At JSM 2011 today, three Google employees (amongst the more than 20 Google delegates there) gave a little insight into how statistical analysis with R yields better results for companies using Google's various advertising products. Bill Heavlin from Google kicked off the session with a talk about conditional regression models, a statistical technique at Google used to evaluate the...

Read more »

A Bayesian Guessing Game

August 3, 2011
By
A Bayesian Guessing Game

You, the player, must think of some set, eg "odd numbers" or "perfect squares," and that'll be your little secret. Now think of some numbers that live in the intersection of your set and the integers {1, 2, ... , 100} -- for example, if you've chosen ...

Read more »

Faster files in R

August 3, 2011
By

R is fairly slow in reading files. read.table() is slow, scan() a bit faster, and readLines() fastest.But all these are nowhere as fast as other tools that scan through files. Let us look at an example. I have in front of me a 283M file.(Small update: the timings where off before. First because R hashes strings, one has to...

Read more »

Tomboy Notes: Personal R Help File

August 3, 2011
By
Tomboy Notes: Personal R Help File

When learning R it is helpful to have your own personal help file. One you create for yourself, with the notes, links, and language you understand (sometimes the help files are not very helpful). Let me introduce you to Tomboy Notes.Tomboy Notes is a l...

Read more »

Data Driven Story Discovery: Working Up a Multi-Layered Chart

August 3, 2011
By
Data Driven Story Discovery: Working Up a Multi-Layered Chart

How many different dimensions (or “columns” in a dataset where each row represents a different sample and each column a different measurement taken as part of that sample) can you plot on a chart? Two are obvious: X and Y values, which are ideal for representing continuous numerical variables. If you’re plotting points, as in

Read more »

WordPress WordCloud with R

August 3, 2011
By
WordPress WordCloud with R

These days one can frequently read about wordclouds created with R, initiated by the release of the wordcloud package by Ian Fellows on July 23rd. So here I am to put in my two cents. I thought about creating a wordcloud of a complete blog history, so I build a script that connects to a

Read more »

RTextTools v1.1 Released

A major upgrade of RTextTools has been released, including many optimizations, UI changes, and features based on feedback from the 2011 CAP Conference in Catania. Changes include the addition of a new low-memory algorithm GLMNET, full user documentation, simplification of the user interface, bundled datasets, better analytics for both virgin a

Read more »

Are students’ teaching evaluations influenced by instructors’ looks?

August 3, 2011
By
Are students’ teaching evaluations influenced by instructors’ looks?

Are students' teaching evaluations influenced by instructors' looks? ggplot2 may help find the answer.The recent release of RcmdrPlugin.KMggplot2 has made ggplot2 available to those who prefer GUI to the command line interface. With the new plugin for ...

Read more »

RcppArmadillo 0.2.28

August 2, 2011
By

Armadillo 2.2.1 came out today (and it looks like 2.2.0 was skipped, tst, tst). It has now been wrapped into release 0.2.28 of RcppArmadillo which is already on CRAN. The NEWS entry is below; a number of these changes were already in the preceding 0...

Read more »

Syntax highlighting of roxygen documentation in TextMate

August 2, 2011
By

With roxygen now on github, the release of roxygen2 and Hadley’s might now behind the project I expect roxygen to gain even more momentum. R development in TextMate is great with the R bundle. Unfortunately the R bundle does not support highlighting of roxygen documentation by default. That was always a sticking point for me

Read more »