Monthly Archives: March 2011

R + EC2 + RStudio Server

March 30, 2011
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R + EC2 + RStudio Server

I’ve been battling memory limits in R for over two years. Although R has numerous resources for high-performance computing, I still couldn’t get around hardware limitations. Things really got out of control last summer when I started analyzing data on how climate change influences population synchrony across large spatiotemporal gradients. My datasets were simply too

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New R User Groups in Tallahasse (FL), Hobart (TAS)

March 30, 2011
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Two new R User Groups have just started up. The first us in Tallahassee, Florida, and their first meeting is on April 10. Spinning to the other side of the globe, the other is in Hobart, the capital of the Australian island state, Tasmania (their first meeting is also on April 8). It's great to see R user groups...

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Globally Set Digits in Sweave

March 30, 2011
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Globally Set Digits in Sweave

I use Sweave regularly for most of my writing and love the way it works. However, one issue that often irks me is the inability to globally set the number of digits to display. Here is a minimal example that illustrates my point. If we now display the numbers using Sexpr, this is what we

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Rcpp workshop in Chicago on April 28th

March 30, 2011
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OverviewThis year's R/Finance conference will be preceded by a full-day masterclass on Rcpp and related topics which will be held on Thursday, April 28, 2011, the Univ. of Illinois at Chicago campus.Join Dirk Eddelbuettel and Romain Fr...

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Rcpp workshop in Chicago on April 28th

March 30, 2011
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OverviewThis year's R/Finance conference will be preceded by a full-day masterclass on Rcpp and related topics which will be held on Thursday, April 28, 2011, the Univ. of Illinois at Chicago campus.Join Dirk Eddelbuettel and Romain Fr...

Read more »

Tor anonymity network using R for website graphics.

March 29, 2011
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Tor anonymity network using R for website graphics.

These graphics look familiar. From the Tor Metrics Portal: "The metrics website uses R to generate custom graphs on demand." See more here: http://metrics.torproject.org/graphs.html.

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Violins of Volatility

March 29, 2011
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Violins of Volatility

A violin plot is a combination box plot and a kernel density plot: it starts with a box plot, and adds a rotated kernel density plot to each side of the box plot. You can create violin plots with the vioplot function (from the vioplot package) package in R. When looking at the volatility of financial instruments, the financial...

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A Simple Instrumental Variables Problem

March 29, 2011
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A Simple Instrumental Variables Problem

When working with labor economics, we often run into issues with selection on variables of interest. Regressing earnings on years of education to estimate the human capital earnings function makes sense at first blush until we imagine that education is … Continue reading →

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Le Monde puzzle [#8]

March 29, 2011
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Le Monde puzzle [#8]

Another mathematical puzzle from Le Monde that relates to a broken calculator (skipping the useless tale): Given a pair of arbitrary positive integers (x,y) a calculator can either substract the same integer from both x and y or multiply either x or y by 2. Is it always possible to obtain equal

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How to Bootstrap in R: The Case of R-squared

March 29, 2011
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How to Bootstrap in R: The Case of R-squared

I recorded a new video tutorial whose original intent was to demonstrate how to write a for loop. As I wanted to make the for loop count for something, I decided that my application would be to write some code that computes the bootstrap approximation ...

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