Help with Matrix package
The first thing is to ensure that you are using an optimized BLAS. On Windows, use Goto's BLAS if you have it (is not currently available and redistribution is not allowed) or one of the pre-built ATLAS-based Rblas.dll on CRAN or (best of all) optimize your own build of ATLAS. The Matrix package depends on an optimized BLAS even more crucially than base R.
On Thu, 13 Oct 2005, rob foxall (IFR) wrote:
Hello all, A colleague at work set me the challenge to convert some MATLAB code into R, to see which is faster. We'd seen that benchmark comparing MATLAB 6.5 to R1.90 (and others), and so I thought that I should be able to get roughly comparable speeds. The code has lots of multiplications of matrixes, transposes, and MATLAB's "repmat". I did the code conversion, and R was about 6 times slower, so I had a closer look at the benchmark comparison and it seems that I should be using the "Matrix" package. Is there any dummies-level help available for this package? I am struggling even to apply simple functions such as "sum" and "mean" to matrixes constructed from this class (not that I need to yet), and more importantly "kronecker", to convert from "repmat". (The help for "kronecker" from the Matrix package doesn't seem to mention kronecker, so I am a bit stuck). Any guidance greatly accepted -- I have read the overview, looked through the various Matrix-listed functions, and unsuccessfully tried searching R-help. Using R version 2.2.0, windows xp.
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595