This is a list of new or updated packages that were released for R in February, 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 February 2010. Follow ... [Read more...]

tephanie asked in 511 today if we were able to get the random seed which was set by set.seed() but we were only given the random numbers (without knowing the seed). This kind of “hacker” questions sound interesting. One dirty solution should be the brute-force method, e.g: # x: the ... [Read more...]

To while away your Friday afternoon, why not explore the nooks and crannies of a 3-D version of the Mandelbrot set: And here's how to create your own 2-D Mandelbrot set in R. [Read more...]

Today is the one year anniversary of the NYC R Statistical Meetup. Starting as a small group meeting in a crowded conference room, Josh Reich established the meetup as the premiere gathering of data geeks in the tri-state area. Over the past year we have had 10 meetups, and two more ... [Read more...]

Besides the new RcppExamples, another new package RcppArmadillo got spun out of Rcpp with the recent release 0.7.8 of Rcpp. Romain and I already had an example of a simple but fast linear model fit using the (very clever) Armadillo C++ library by... [Read more...]

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When I read in the abstract of the recent A General Purpose Sampling Algorithm for Continuous Distributions, published by Christen and Fox in Bayesian Analysis that We develop a new general purpose MCMC sampler for arbitrary continuous distributions that requires no tuning. I am slightly bemused. The proposal of the ... [Read more...]

One of the main goals of analyzing clinical data is to produce a report. (What, you thought it was to make the world a better place?) The R Project has, of course, all the tools you need to perform the statistical analysis, calculate the tables of results, and present conclusions ... [Read more...]

I've been working mainly on abstract ABM, and I really don't need all that bells and whistles, and besides I've had some problems when trying to handle the relation between the real coordinate system and NetLogo own system. What I want is to use a GIS ... [Read more...]

Version 0.1.0 of RcppExamples, a simple demo package for Rcpp should appear on CRAN some time tomorrow. As mentioned in the post about release 0.7.8 of Rcpp, Romain and I carved this out of Rcpp itself to provide a cleaner separation of code t... [Read more...]

The puzzle in last Saturday edition of Le Monde is made of two parts: Given a 10×10 grid, what is the maximum number of nodes one can highlight before creating a parallelogram with one side parallel to one of the axes of the grid? What is the maximum number of nodes ... [Read more...]

From a recent mailing from Stata (highlighting by me): Funnily enough, there is a Daniel Rubin, a bio-informatics person here at Stanford. [Read more...]

The nls() function has a well documented (and discussed) different behavior compared to the lm()’s. Specifically you can’t just put an indexed column from a data frame as an input or output of the model. __ nls(data[,2] ~ c + expFct(data[,4],beta), data = time.data, + start = start.list) Error ... [Read more...]

Cluster Analysis is a useful technique for classifying the members of a group (people, events, measurements, etc) into "similar" groups. How "similar" is defined depends on the application, but generally involves looking at a number of attributes of the group. For example, we could cluster people by looking at their ... [Read more...]

Recently, I was busy testing the following strategy: If SPY and VIX daily returns are positive, then short SPY at close and keep it for one day. The strategy is dump simple and it has very good feature – short side. There are not so many successful short side strategies. For ... [Read more...]

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Version 0.7.8 of the Rcpp R / C++ interface classes is now on CRAN and in Debian. As of right now. Debian has already built packages for eight more architectures; and CRAN has built the Windows binary. Oh, and cran2deb had Debian packages for 'testin... [Read more...]

Jeff Lewis at UCLA told me he teaches principal components with an image reconstruction example. This got me inspired to try it myself. A snapshot appears below, showing how the image quality improves quickly with a relatively small number of principal components. A full, Sweaved write up is here, making ... [Read more...]

For those people who prefer to be shown how to do something rather than read the instructions, there are some videos on using R available online. Here are the ones I know about. Please add links to other similar resources in the comments. R videos Learn R Toolkit What is ... [Read more...]

Darren Wraith pointed out to me this site proposing a whole series of videos introducing to R. (Unfortunately in a Windows environment.) This can be handy when facing students with no R background… Filed under: R, Statistics, University life Tagged: course, video [Read more...]