On Sun, 6 Apr 2008, Mathieu Ribatet wrote: > Dear list members, > > I've got a small question on matrix multiplications in a C code. Because > of a really cpu demanding likelihood, I had to use a C code within an R > function wrapper. I'm pretty sure that there is already one good code > for matrix multiplication in C - maybe in the R source code itself - but > I wasn't able to find it. > > Anyone as an idea on how to handle matrix multiplications?
Well, R does use fast C code where available: see matmult in src/main/array.c which calls the BLAS. It works best if you have an optimized BLAS: otherwise it may not be as fast as the simple version used when there are NAs present. -- Brian D. Ripley, [EMAIL PROTECTED] 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 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
