Wanderlust

March 4, 2009
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We Americans have a reputation as being unworldly. Given the results of the most recent Pew survey, perhaps we deserve it. Evidently, the majority of us never move out of our home states.

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Click Tracks and Beat Detection

March 4, 2009
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Being a drummer, a programmer and a fan of statistical analysis, this post on the (unnaturally) perfect timing of drum parts recorded to a click track was a real delight to me. Of course, many claims in the post are odd: it seems hard to imagine that a...

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RQuantLib 0.2.11

March 3, 2009
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The changes in Rcpp that I blogged about a few days ago required a few small changes in RQuantLib. Not really much more that prefixing std:: in a number of variable declarations and a few member function calls -- so this is definitely a minor maintenance release. New source and binary packages have already been pushed to CRAN and Debian.

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Simulate parameters of a tobit model

March 3, 2009
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I got an email, asking me if our arm package can simulate tobit model to get simulated parameters. Indeed, arm does not suport tobit model. It only support sim() for lm, glm and mer classes in R. But it is not difficult to get a tobit verison of sim(). Here are the steps:1. fit a tobit...

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Simulate parameters of a tobit model

March 3, 2009
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I got an email, asking me if our arm package can simulate tobit model to get simulated parameters. Indeed, arm does not suport tobit model. It only support sim() for lm, glm and mer classes in R. But it is not difficult to get a tobit verison of sim(). Here are the steps:1. fit a tobit...

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Project Euler Problem #28

March 2, 2009
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Problem 28 on the Project Euler website asks what is the sum of both diagonals in a 1001×1001 clockwise spiral. This was an interesting one: the relationship between the numbers on the diagonals is easy to deduce, but expressing it succinctly in R...

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Color Schemes for R Bar Plots

March 1, 2009
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Color Schemes for R Bar Plots

A recurrent source of irritation for me is the absence of a good default behavior in R for choosing the color scheme for bar plots. A stacked bar plot looks only as good as the color scheme you use. In hope of finding a usable scheme that I could settl...

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Your flight is moving …

March 1, 2009
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Your flight is moving …

THE VALUE OF NOT FOLLOWING INSTRUCTIONS As Shane Frederick has noted, if you say “A bat and a ball cost $1.10. The bat costs $1 more than the ball. How much is the ball?”, you will notice that the vast majority of your friends will say “10 cents” instead of the correct “5 cents”, because

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Rcpp 0.6.4

March 1, 2009
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A new maintenance version of Rcpp (now at 0.6.4) was just pushed to CRAN and has been uploaded to Debian. Rcpp is a set of utility classes that provide interfaces for transferring the major R data types to C++ and back which makes it easier to extend R with dynamically loadable code written in C or C++. This version changes how use...

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What is R?

March 1, 2009
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Highlights R is a free software environment for statistical computing and graphics. It compiles and runs on a wide variety of UNIX platforms, Windows and MacOS.   If you wish to download R, please choose your preferred CRAN mirror. Basic questions about R like how to download and install the software, or what the license terms are, are answered

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What is R?

March 1, 2009
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What is R?

Highlights R is a free software environment for statistical computing and graphics. It compiles and runs on a wide variety of UNIX platforms, Windows and MacOS.   If you wish to download R, please choose your preferred CRAN mirror. Basic questions ...

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Project Euler Problem #22

March 1, 2009
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Problem 22 on Project Euler proves a text file containing a large number of comma-delimited names and asks us to calculate the numeric sum of the alphabetical score for each name multiplied by the name’s position in the original list. This is mad...

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Plotting PDQ Output with R

February 27, 2009
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Plotting PDQ Output with R

One the nice things about PDQ-R (coming in release 5.0) is the ability to plot PDQ output directly in R. Here's a PDQ-R script, together with the corresponding graphical output, that I knocked up to show the effect on the throughput curve of adding mor...

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R in The Windy City

February 27, 2009
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In honor of me moving to Chicago, the powers who abide have decided to hold the first annual “R/Finance conference for applied finance using R” conference in Chicago this year. The dates are April 24-25, 2009. R/Finance 2009: Applied Finance with R To those who made the decision on location, I’m pleased but slightly embarrassed that you

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Data Analysis Workflow… Part 1 of Infinity

February 26, 2009
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One of the many things that I sit around pondering when I should be doing productive things is the idea of analytical workflow. I have only worked with one analytical guru who I felt really gave thought and structure to workflow and its impact on analyist productivity. When I talk about workflow I mean the

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Review of ‘Applied Econometrics in R’ in JSS

February 25, 2009
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A short review of Kleiber and Zeileis' excellent Applied Econometrics with R is now out at the (online) Journal of Statistical Software.

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Absolutely great resource

February 25, 2009
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A very nice resource which helped me a lot in kickstarting my Sweave efforts is Learning to Sweave in APA Style by clementi on scribd. This is a down to earth tutorial containing a lot of good tips! See for yourself:Learning to Sweave in APA Style ...

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Absolutely great resource

February 25, 2009
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A very nice resource which helped me a lot in kickstarting my Sweave efforts is Learning to Sweave in APA Style by clementi on scribd. This is a down to earth tutorial containing a lot of good tips! See for yourself:Learning to Sweave in APA Style ...

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R/Finance conference in Chicago in April: Registration now open

February 23, 2009
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Regarding the aforementioned R/Finance conference that will take place at the end of April here in Chicago, we announced earlier today that the conference website is now available. It provides information about the program, speakers and other details as well as a link to registration details. See you in Chicago in April!

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Sorry, you said you want a stats revolution?

February 23, 2009
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Sorry, you said you want a stats revolution?

ALL ABOUT REVOLUTION COMPUTING’S R DISTRIBUTION Decision Science News was intrigued by a company called REvolution Computing that got some attention of late for spinning their own mix of the R language for statistical computing and giving it away for free. So DSN asked to interview them to see what it’s all about Decision Science

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Project Euler Problem #15

February 22, 2009
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Problem 15 on Project Euler asks us to find the number of distinct routes between the top left and bottom right corners in a 20×20 grid, with no backtracking allowed. I originally saw this type of problem tackled in the book Notes On Introductory ...

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PDQ-R Lives!

February 22, 2009
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PDQ-R Lives!

After some fiddling to get things linked correctly to the R binaries on my new Macbook, the first PDQ-R test model has run successfully! Here 'tiz ...This is an important step for PDQ development and is due entirely to the efforts of Phil Feller. Natur...

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R graphics: margins are way to large

February 22, 2009
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R graphics: margins are way to large

For me R has a very nice and powerfull capabilities for graphics (for example see this gallery). However, I dislike the default setting for margins and placement of axis numbers and labels. Since I always forget the setting of parameters I prefer I am adding this post. For example:library(package="MASS")Sigma mu tmp plot(tmp, xlab="X variable (unit)", ylab="Y variable...

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R graphics: margins are way to large

February 22, 2009
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R graphics: margins are way to large

For me R has a very nice and powerfull capabilities for graphics (for example see this gallery). However, I dislike the default setting for margins and placement of axis numbers and labels. Since I always forget the setting of parameters I prefer I am adding this post. For example: library(package="MASS")Sigma mu tmp plot(tmp, xlab="X variable (unit)", ylab="Y variable...

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Illinois long-term selection experiment for oil and protein in corn

February 22, 2009
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Illinois long-term selection experiment for oil and protein in corn

Researchers at the University of Illinois are conducting one of the longest experiments in biology - Illinois long-term selection experiment for oil and protein in corn. The experiment started in 1896 and is still active! In esence they are selecting l...

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Project Euler Problem #13

February 21, 2009
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Problem 13 on Project Euler asks us to sum 100 50-digit numbers and give the first 10 digits of the result. This is pretty easy. Note we are using R’s integer division operator %/% to discard the remainder of the large summed integer and just giv...

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Project Euler Problem #14

February 21, 2009
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Problem 14 on the Project Euler site asks us to find the longest chain under 1 million created using the Collatz mapping. This is fairly straightforward, although performance again is not great: ## Problem 14 # Collatz conjecture problem14 <-&...

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Project Euler Problem #12

February 21, 2009
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Problem 12 on the Project Euler site asks: What is the value of the first triangle number to have over five hundred divisors? A triangular number T(n) is defined as . The R code below consists of a solution, which involves the fact that the number of proper divisors of an integer n can be

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How Facebook and Google use R

February 21, 2009
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How Facebook and Google use R

How Facebook and Google use R Interesting read.  rpart comes in handy again.

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