There's new video at the Video Rchive of a JD Long presentation: Amazon Elastic Map-Reduce (So Easy an Economist Can Do It). I'm on a plane right now and the in-flight wi-fi isn't quite up to playing the 30-minute video, but judging from the slides it looks like a nice, practical demonstration of getting a map-reduce computation programmed in...
1413 search results for "map"
Map-reduce in R with Amazon EMR
James Long discusses his experience performing large distributed calculations in R on Amazon's Elastic Map-reduce service. James also provides a live demonstration of using R with EMR to stochastically calculate pi.
How to map your Twitter social network
Ever wondered which Twitterers you and a friend share? Using R and the twitteR package, there's an easy way to find out. Cornelius Puschmann hacked together some R code to do just that for the Humanities and Technology Camp and it seems to work pretty well. Just replace 'coffee001' with the your Twitter username, 'mypassword' with your Twitter password,...
LSPM Joint Probability Tables
I've received several requests for methods to create joint probability tables for use in LSPM's portfolio optimization functions. Rather than continue to email this example to individuals who ask, I post it here in hopes they find it via a Google...
House Mountain Hike
My wife Mary and my Dad Wesley and I took a hike this weekend (5/14/10) to the House Mountain state recreation area in Knox county, Tennessee. The hike was about 3.8 miles with a total elevation gain of around 1000 feet (940.23ft by GPS). The plot below gives the elevation profile over the course of
A small customization of ESS
JD Long (at Cerebral Mastication) posted a question on Twitter about an artifact in ESS, where typing “_” gets you “<-”. This is because in the early days of S+, “_” was an allowed assignment operator, and ESS was developed in that era. Later, it was disallowed in favor of “<-” and “=”, so ESS 
In case you missed it: April Roundup
In case you missed them, here are some articles from last month of particular interest to R users. We announced the availability of Revolution R Community 3.2 (based on R 2.10.1), now 100% open source, and including a new doMC package for parallel computing on Windows. We announced that Revolution R Enterprise is now available free of charge to...
Rcpp 0.8.0
Summary Version 0.8.0 of the Rcpp package was released to CRAN today. This release marks another milestone in the ongoing redesign of the package, and underlying C++ library. Overview Rcpp is an R package and C++ library that facilitates integr...
Collect and Parse GPS (NMEA0183) Data in R
I recently wrote a serial connection for R-2.11.0 so that I can communicate with serial devices, for example an old Garmin eTrex Legend. This GPS device is able to output NMEA0183 sentences to a standard serial port (4800,8,1,N). I hooked up the device and used the serial connection to collect some data using some R
ggplot2: Waterfall Charts
Waterfall charts are often used for analytical purposes in the business setting to show the effect of sequentially introduced negative and/or positive values. Sometimes waterfall charts are also referred to as cascade charts. In the next few paragraphs I will show how to plot a waterfall chart using ggplot2. Data A very small fictional dataset 
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
