R

Speeding up R with Intel's Math Kernel Library (MKL)

I did some comparisons of the generic BLAS with Intel's MKL (both sequential and parallel) on a Dell PowerEdge 610 server with dual hyperthreading 6-core 3.06GHz Xeon X5675 processors.  Here are the results from an R benchmarking script (Normal R indicates the generic BLAS,  sMKL is the sequential (single core Intel MKL, and pMKL is the parallel Intel MKL using all 24 threads available on this system).

Shrinking R's PDF output

R is great for graphics, but I've found that the PDF's R produces when drawing large plots can be extremely large. This is especially common when using spplot() to plot a large raster. I've made a 15 page PDF full of rasters that was hundreds of MB in size.  Obviously I don't need all the detail (every pixel of the raster) represented in the pdf and would rather have it reduced in size somehow.  So I wrote an R function to automate the following:

    MODIS processing with R, GDAL, and the NCO tools

    I use MODIS data for analysis of vegetation dynamics around the world.  The native HDF file format provided by NASA is great for archiving the data (it's amazing how much information they include in each file), but unfortunately there aren't many tools for directly (and easily) extracting data stored across files like there are for the NetCDF format.  I wanted to be able to use the NCO tools to extract timeserie