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...

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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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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...

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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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S4 timeDate Package

May 23, 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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Portfolio Risk Surfaces

May 23, 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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R Function of the Day: sample

May 23, 2010
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R Function of the Day: sample

The R Function of the Day series will focus on describing in plain language how certain R functions work, focusing on simple examples that you can apply to gain insight into your own data. Today, I will discuss the sample function. Random Permutations In its simplest form, the sample function can be used to return

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Stability Watch Views

May 22, 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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Variable selection using automatic methods

May 22, 2010
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When we have a set of data with a small number of variables we can easily use a manual approach to identifying a good set of variables and the form they take in our statistical model. In other situations we may have a large number of potentially important variables and it soon becomes a time

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Helping the blind use R – by exporting R console to Word

May 22, 2010
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Preface – R seems a natural fit for the blind statistician For blind people who wish to do statistics, R can be ideal. R command line interface offers straight forward statistical scripting in the form of question (what is the mean of x) followed by an answer (0.2). That is, instead of point-and-click dialog boxes with jumping windows of...

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Using R for Introductory Statistics, 3.1

May 21, 2010
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Using R for Introductory Statistics, 3.1

Pairs of categorical data The grades data.frame holds two columns of letter grades, giving pairs of categorical data, like so: prev grade 1 B+ B+ 2 A- A- 3 B+ A- ... 122 B B This type...

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