Monthly Archives: December 2009

Un-Wrapping a Sphere with R

December 8, 2009
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Un-Wrapping a Sphere with R

  Premise I was recently asked to print out a fabric pattern that could be used to cover a sphere, about the size of a ping pong ball, for the purposes of re-creating a favorite cat toy (quite important). Thinking this over, I realized that this was basically a map projection problem-- and could probably be solved by scaling...

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Package Update Roundup: Nov 2009

December 8, 2009
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This is a list of new or updated packages that were released for R in November, as announced on the r-packages mailing list. To include other updates on this list, please email David Smith. For a complete list of all updates on CRAN, see the CRANberries archive for November 2009. Follow package name links for ratings and other information...

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Sciviews

December 8, 2009
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Sciviews

I was finally able to get Sciviews (most of it) work on my Linux machine. As before, I got some error message when opening the R terminal for the first time; by ignoring the error messages and manually install several "sv" packages locally (into my hom...

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R Tutorial Series: Multiple Linear Regression

December 8, 2009
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R Tutorial Series: Multiple Linear Regression

In R, multiple linear regression is only a small step away from simple linear regression. In fact, the same lm() function can be used for this technique, but with the addition of a one or more predictors. This tutorial will explore how R can be used to...

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R Function Usage Frequencies, Take 2

December 8, 2009
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R Function Usage Frequencies, Take 2

Yesterday, Hadley Wickham commented on my post on the frequency of calling various R functions that it would be helpful to have the number of packages that call a function in addition to the number of times that the function is called. I compiled the relevant data last night: you can grab it here This

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Implementing Push and Pop in R

December 7, 2009
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Having grown up with Perl, there are two functions that I desperately miss while programming in R: push and pop. Continually writing1 vector <- c(vector, new.entry)tries my patience, while writing1 2 vector <- rep(NA, inscrutable.constant) vector <- new.entrymakes me feel like I’m programming in C, rather than a higher-level programming language. That said, here’s a simplistic hack to provide

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R, REvolution named in top analytic trends for 2010

December 7, 2009
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Author and enterprise software executive Nenshad Bardoliwalla lists his Top 10 Trends for 2010 in Analytics, Business Intelligence, and Performance Management at the website Enterprise Irregulars. If you've been following the Business Intelligence space (and who hasn't, right?) you'll recognize some familiar themes: predictive analytics, Web 2.0, Software-as-a-Service, risk, IBM. What's interesting about this list is that it raises...

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Advanced SNA with R, via Harvard Political Nets Conference

December 7, 2009
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End of semester madness has begun, so posting will likely be light this week. To keep you busy, David Lazer recently posted the five video series of the Goudreau-Hunter tutorial on social network analysis using R from the 2009 Harvard Political Networks Conference. Each video run about 60 minutes, so these will literally provide hours

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R Function Usage Frequencies

December 7, 2009
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R Function Usage Frequencies

A few months ago I decided to apply word frequency analysis ideas to R code. My idea was simple: the functions that one should invest the most effort into learning are precisely those functions that are used most frequently in real world code. In fact, this simple idea can be applied to spoken languages as

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Understanding the Science of CO2’s Role in Climate Change: 3 – How Green House Gases Trap Heat

December 7, 2009
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Understanding the Science of CO2’s Role in Climate Change: 3 – How Green House Gases Trap Heat

This post, the 3rd (1st here, 2nd  here) in the series on Understanding the Science of CO2’s Role in Climate Change, discusses how water vapor, CO2, CH4, O3 and N2O  absorb and emit the Earth’s longwave radiation, changing the Earth’s energy balance. I’ve made a 5 panel chart that shows spectra data for 5  greenhouse

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