Following up on my initial post announcing gcbd, here is a brief note on a new version. The initial post announced version 0.2.2 which was the first CRAN version of gcbd. I updated to 0.2.3 when I made the aforementioned first blog post about gcbd w... [Read more...]

Since the puzzle in this week (-end) edition of Le Monde is not (easily) solvable via an R program, I chose to go back to an older puzzle that my students can solve. Eleven [distinguishable] token are [arbitrarily] distributed around a 200 meter perimeter-long ring. They all start moving at the ... [Read more...]

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Having done the plot with python+matplotlib, thought I would have a go reproducing it in R, using only the builtin "plot". So, just to recap - this is a plot of the sun times (rise/set,twilight and blinding) as generated by the great python library pyephem. The R ... [Read more...]

Here is how to improve your charts, graphs, maps, and plots: Erase non-data ink. Erase redundant data ink. Maximize the ratio of data to ink. Show data variation, not design variation. The surface area of graphical elements should be directly proportio... [Read more...]

I’ve just released the newest version of ProjectTemplate. The primary change is a completely redesigned mechanism for automatically loading data. ProjectTemplate can now read compressed CSV files, access CSV data files over HTTP, read Stata, SPSS and RData binary files and even load MySQL database tables automatically. For my ... [Read more...]

Install the plug-in is quite simple, we only need to follow the instructions that we’ll find at the project’s page: http://www.walware.de/goto/statet The requirements are Java 5 (1.5) or higher, Eclipse IDE and the R package: rJava. The rj package is also recommended. In my case, ... [Read more...]

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The functions head and tail are very useful for working with lists, tables, data frames and even functions.But they do not work on strings. It is easy to define such functions__ strtail + if(n+ substring(s,1-n) + else + substring(s,nchar(s)-n+1)+ }__ strhead + if(n+ substr(s,1,nchar(... [Read more...]

Here are some quick crib notes on getting R talking to CouchDB using Couch's ReSTful HTTP API. We'll do it in two different ways. First, we'll construct HTTP calls with RCurl, then move on to the R4CouchDB package for a higher level interface. I'll a... [Read more...]

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A few hours ago, Jens Oehlschlägel has announced on the R-help mailing list of the release of a new version of the ff package. The ff package provides data structures that are stored on disk but behave (almost) as if they were in RAM by transparently mapping only a ... [Read more...]

Just realized that this SEM package for R has released version 1.0. Great... [Read more...]

I was brought up in Australia, where we got rid of 1¢ and 2¢ coins in my childhood. Nobody missed them, at least as I recall. I certainly didn't: they were useless, even at the age when I might by lollies (candy) for 2¢ apiece. But then again, I'd never buy one, and ... [Read more...]

The other day, as an excuse to play around with custom iterators, I created some completely over-engineered code to calculate the Fibonacci sequences. But surely such a simple function can be implemented in fewer than my 15 lines? (Rick Wicklin, who writes the SAS blog The Do Loop, thinks so too.) ... [Read more...]

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Using Kalman Filter for CIR interest rate model parameter estimation was introduced at my previously post Kalman Filter finance, soon after that I got a few comments saying the final results are unstable and highly depend on the initial values, that's... [Read more...]