Monthly Archives: August 2010

Homogeneity analysis of hierarchical classifications

August 10, 2010
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Homogeneity analysis of hierarchical classifications

I've spent more years than I care to remember analysing vegetation survey data (typically species abundances in plots) using a variety of software including my own algorithms coded in FORTRAN and C++. A recent query on the r-help list, about how to determine the number of groups to define in a hierarchical classification produced with the hclust function, prompted...

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Homogeneity analysis of hierarchical classifications

August 10, 2010
By
Homogeneity analysis of hierarchical classifications

I've spent more years than I care to remember analysing vegetation survey data (typically species abundances in plots) using a variety of software including my own algorithms coded in FORTRAN and C++. A recent query on the r-help list, about how to det...

Read more »

RQuantLib 0.3.4

August 9, 2010
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A fresh release of RQuantLib is now on CRAN and in Debian. RQuantLib combines (some of) the quantitative analytics of QuantLib with the R statistical computing environment and language. This follows the 0.3.3 release from last week and has again a num...

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RQuantLib 0.3.4

August 9, 2010
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A fresh release of RQuantLib is now on CRAN and in Debian. RQuantLib combines (some of) the quantitative analytics of QuantLib with the R statistical computing environment and language.This follows the 0.3.3 release from last week and has again ...

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An HSV colour wheel in R

August 9, 2010
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An HSV colour wheel in R

If you’ve read any of my previous posts, you’ll notice that they’re rather scanty on colour. There’s a reason for this. Mainly, that to get a good colour output takes some time. I recently read a commentary in Nature methods (sorry if you don’t have access to it, but this looks like it may be

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R unfolds the history of the Afghanistan war

August 9, 2010
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R unfolds the history of the Afghanistan war

Drew Conway continues his analysis of the Wikileaks data. Having concluded that the data appear legitimate (except perhaps in one region, based on a Benford's Law analysis of the numbers in the documents), Drew follows up with a spatio-temporal analysis of activity within Afghanistan, based on the datelines of the documents themselves (click to enlarge): Each panel represents a...

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Quickly Find the Class of data.frame vectors in R

August 9, 2010
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Aviad Klein over at My ContRibution wrote a convenient R function to list the classes of all the vectors that make up a data.frame. You would think apply(kyphosis,2,class) would do the job but it doesn't - it calls every vector a character class. Aviad wrote an elegant little function that does the job perfectly without having to load any...

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Useful functions for data frames

August 9, 2010
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The R software system is primarily command line based so when there are large sets of data it is not easy to browse the data frames. There are various useful functions for working with data frames. For example, after loading data from a text file we might want to view the first few lines of a

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GitHub Stats on Programming Languages

August 9, 2010
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GitHub Stats on Programming Languages

GitHub has become a popular site for Open Source Developers to stash code and collaborate on projects.  The following are some stats and analysis related to programming languages in use based upon the number of users and repositories.  T...

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R has the best models

August 9, 2010
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R has the best models

We had a great time at the JSM conference, and I really enjoyed meeting with all the useRs at the Revolution mixer on Wednesday evening (where this photo was taken). Hope everyone had a great time -- thanks for coming!

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