I have a few posts nearing completion, but meanwhile a weekend break for art. Big thanks to Simon Urbanek and Jeffrey Horner, creators of Cairo, a library for the programming language R. Have you noticed how R can’t anti-alias (fancy way for saying smooth out lines and curves when creating a bit-mapped image)? Cairo can.
For Part I, Parallelism in R, click here.
Tuesday night I again had the opportunity to present on high performance computing in R, at the Los Angeles R Users’ Group. This was the second part of a two part series called “Taking R to the Limit: High Performance Computing in R.” Part II discussed ways to work with large datasets...
At any R Q&A site, you’ll frequently see an exchange like this one: Q: How can I use a loop to ? A: Don’t. Use one of the apply functions. So, what are these wondrous apply functions and how do they work? I think the best way to figure out anything in 
Hic sunt dracones used to be placed on maps, as a way to denote a dangerous or otherwise unexplored territory. We might as well write it all over R-related material used in introductory classes, because students seems to be really (…)
Visualisation of Activity in Afghanistan using the Wikileaks data from Mike Dewar on Vimeo.
The latest visualization of the WikiLeaks data compiled by our group is an animation of the intensity of report observations in Afghanistan over the six year period in the WikiLeaks data. Team member Mike Dewar did the vast majority of work for
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...
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...
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...
Below is a visualization of the Wikileaks data produced in collaboration with Michael Dewar. This plot shows attacks in the data set by year and type, projected onto a map of Afghanistan with district boundaries.
This visualization is certainly not perfect, i.e., some colors are difficult to discern, but it does provide added insight to the
We've looked before at how you can annotate geographical maps using R, but what if you want to overlay data onto a globe of the Earth, using Google Earth? The RKML package for R (from the OmegaHat project) allows you to do just that, by providing a high-level interface from R to generate KML files, which in turn are...
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
