R badly lags matlab on performance?
On Sat, Jan 03, 2009 at 06:59:29PM +0100, Stefan Grosse wrote:
On Sat, 3 Jan 2009 22:25:38 +0530 Ajay Shah <ajayshah at mayin.org> wrote:
AS> system.time(for (i in 1:10000000) {a[i] <- a[i] + 1})
AS> I wonder what we're doing wrong!
it is no secret that R does badly with loops. Thats why it is
recommended to use vectorized operations.
But there's a big difference even on the vectorised version: a <- a + 1. Why should that be? Both systems should merely be handing down to the BLAS. The (stock) R install has a less carefully setup BLAS as compared with the (stock) matlab install?
Ajay Shah http://www.mayin.org/ajayshah ajayshah at mayin.org http://ajayshahblog.blogspot.com <*(:-? - wizard who doesn't know the answer.