The guessing game in R (with a twist, of course)

May 27, 2010
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Maybe you remember playing this one as a kid. If you are about my age, you may have even created a version of this game as one of your first computer programs. You guess a number, the computer tells you if you if you are too low or high. I’ve limited the number of maximum

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Getting Parent Material Data out of SSURGO

May 27, 2010
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  Parent material data is stored within the copm and copmgrp tables. The copm table can be linked to the copmgrp table via the 'copmgrpkey' field, and the copmgrp table can be linked to the component table via the 'cokey' field. The following queries illustrate these table relationships, and show one possible strategy for extracting the parent material information...

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Canadian CPI: Visualization Brainstorm

May 27, 2010
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After finishing the R prototype for data visualization, I've started abstracting the various methods necessary to create beautiful graphs. While there's no preliminary version of the R package yet, I think I've taken a number of exciting steps. These include: Abstracting graph objects. Objects such as lines, scatter plots, and other graph types can all

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Solving Factor Models

May 27, 2010
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(This article was first published on Rmetrics blogs, and kindly contributed to R-bloggers) To leave a comment for the author, please follow the link and comment on his blog: Rmetrics blogs. R-bloggers.com offers daily e-mail updates about R news and tutorials on topics such as: visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL, Eclipse, git, hadoop, Web...

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Map-reduce in R with Amazon EMR

May 27, 2010
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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...

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Map-reduce in R with Amazon EMR

May 27, 2010
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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.

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WU Wien presentations

Last week I had the opportunity to spend a few days at the Institute for Statistics and Mathematics of the WU Vienna / Wirtschaftsuniversitaet Wien. On Thursday, I gave a seminar on Rcpp and RInside introducing all the recent work with Romain on makin...

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WU Wien presentations

May 27, 2010
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Last week I had the opportunity to spend a few days at the Institute for Statistics and Mathematics of the WU Vienna / Wirtschaftsuniversitaet Wien. On Thursday, I gave a seminar on Rcpp and RInside introducing all the recent work with Romain on making...

Read more »

WU Wien presentations

Last week I had the opportunity to spend a few days at the Institute for Statistics and Mathematics of the WU Vienna / Wirtschaftsuniversitaet Wien. On Thursday, I gave a seminar on Rcpp and RInside introducing all the recent work with Romain on makin...

Read more »

How to map your Twitter social network

May 26, 2010
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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,...

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Zone of instability

May 26, 2010
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Zone of instability

I woke up from my afternoon nap feeling a bit off-kilter, so I decided to go for another random walk. In particular, I wanted a journey that avoided the center, but didn’t just run for an exit either. After playing around for a while I came up with this: # Take a wacky walk, return

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Voter targeting with R

May 26, 2010
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Voter targeting with R

Voter targeting for turnout is the process of scoring registered voters using demographic and electoral variables taken from voter lists and commercial databases. The score of all voters together is used to predict overall turnout, which determines the allocation of campaign resources and directs strategy for voter contact and communication. Targeting for turnout is a

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Testing Out my Pitch F/X Data

May 25, 2010
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Testing Out my Pitch F/X Data

I recently got all the Pitch F/X data downloaded from Gameday, and have been fiddling around. I certainly don't have the physics knowledge to really talk about the movement at this point, and I'm still acquainting myself with the data format and what e...

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Use SQL queries to manipulate data frames in R with sqldf package

May 25, 2010
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I've covered a few topics in the past including the plyr package, which is kind of like "GROUP BY" for R, and the merge function for merging datasets. I only recently found the sqldf package for R, and it's already one of the most useful packages I've ever installed. The main function in the package is sqldf(), which takes...

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German Tanks, Statistical Intelligence

May 25, 2010
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German Tanks, Statistical Intelligence

In World War II, the Allies had a problem: German tanks were often captured, but how many more did the Nazis have in reserve? Allied intelligence estimated around 1400 Panther tanks were being produced a month: a formidable arsenal, and perhaps an insurmountable one given the much smaller numbers being captured or destroyed. But those captured tanks provided exactly...

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The Kalman Filter For Financial Time Series

May 25, 2010
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The Kalman Filter For Financial Time Series

Every now and then I come across a tool that is so bogged down in pages of esoteric mathematical calculations, it becomes difficult to get even a simple grasp of how or why they might be useful. Even worse, you exhaustively search the internet to find ...

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How many tanks? MC testing the GTP

May 25, 2010
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How many tanks? MC testing the GTP

It’s 1943 and you work for the good guys. A handful of German tanks have been captured, and each one has a serial number. This is back when serial numbers were still presumed to come in serial, one right after the other. Given your collection of numbered tanks, and assuming that any existing tank was

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extrapolation and interpolation The most important lesson I…

May 25, 2010
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extrapolation and interpolation
The most important lesson I…

extrapolation and interpolation The most important lesson I learned from this book:  regression is reliable for interpolation, but not for extrapolation.  Even further, your observations really need to cover the whole gamut of causal variables, inter...

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SQLite as an alternative to shapefiles, and some GPS fun in R

May 24, 2010
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Finally made it out to Folsom Lake for a fine day of sailing and GPS track collecting. Once I was back in the lab, I downloaded the track data with gpsbabel, and was ready to import the data into GRASS. # import GPX from GPS: gpsbabel -t -i...

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Chicago R Meetup: Healthier than Drinking Alone

May 24, 2010
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Chicago R Meetup: Healthier than Drinking Alone

I’m kinda blown away by the number of folks who have joined the Chicago R User Group (RUG) in the last few weeks. As of this morning we have 65 people signed up for the group and 25 who have said that they are planning on attending the meetup this Thursday (yes, only 3 days

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Webinar: R analytics and Business Intelligence dashboards

May 24, 2010
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On Wednesday next week, Revolution will be hosting a joint webinar with open-source Business Intelligence software maker Jaspersoft and open-source Business Intelligence services company OpenBI. Together, we'll be talking about making BI dashboards even more powerful by integrating custom visualizations and advanced predictive models from R. If you create advanced analytics in R and are looking for a way...

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Example 7.38: Kaplan-Meier survival estimates

May 24, 2010
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Example 7.38: Kaplan-Meier survival estimates

In example 7.30 we demonstrated how to simulate data from a Cox proportional hazards model.In this and the next few entries, we expand upon support in R and SAS for survival (time-to-event) models. We'll start with a small, artificial dataset of 19 su...

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Rmetrics AMPL Interface

May 24, 2010
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(This article was first published on Rmetrics blogs, and kindly contributed to R-bloggers) To leave a comment for the author, please follow the link and comment on his blog: Rmetrics blogs. R-bloggers.com offers daily e-mail updates about R news and tutorials on topics such as: visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL, Eclipse, git, hadoop, Web...

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THETA AG uses Rmetrics

May 24, 2010
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(This article was first published on Rmetrics blogs, and kindly contributed to R-bloggers) To leave a comment for the author, please follow the link and comment on his blog: Rmetrics blogs. R-bloggers.com offers daily e-mail updates about R news and tutorials on topics such as: visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL, Eclipse, git, hadoop, Web...

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Introduction to using R with org-babel, Part 1

May 23, 2010
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This post originally appeared on my Wordpress blog on May 23, 2010. I present it here in its original form. In my opinion, the description of orgmode by its creator as a tool "for keeping notes, maintaining ToDo lists, doing project planning,...

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Introduction to using R with org-babel, Part 1

May 23, 2010
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This post originally appeared on my Wordpress blog on May 23, 2010. I present it here in its original form. In my opinion, the description of orgmode by its creator as a tool "for keeping notes, maintaining ToDo lists, doing project planning,...

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R Function of the Day: sample

May 23, 2010
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This post originally appeared on my Wordpress blog on May 23, 2010. I present it here in its original form. The R Function of the Day series will focus on describing in plain language how certain R functions work, focusing on simple example...

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R Function of the Day: sample

May 23, 2010
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This post originally appeared on my Wordpress blog on May 23, 2010. I present it here in its original form. The R Function of the Day series will focus on describing in plain language how certain R functions work, focusing on simple example...

Read more »

Code and brief instruction for graphing Twitter with R

May 23, 2010
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Code and brief instruction for graphing Twitter with R

Edit: I’ve posted an updated version of the script here. It is not quite as compressed as Anatol’s version, but I think it’s a decent compromise between readability and efficiency. Edit #2 And yet another update, this one contributed by Kai Heinrich. I hacked together some code for R last night to visualize a Twitter

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