[Rcpp-devel] Significant difference in performance when computing Ax

[Avraham Adler]

I understand and agree that it is a feature; I just should have
realized that crossprod using a fast BLAS is an unfair comparison to
non-BLAS using routines. Then again, it's another reason to use fast
BLAS's. I wish that R for windows would allow the use of an optimized
LAPACK too. Oh well.

Thanks,

Avi

On Sun, Apr 27, 2014 at 3:01 PM, Dirk Eddelbuettel <edd at debian.org> wrote:
>
> On 27 April 2014 at 14:34, Avraham Adler wrote:
> | I feel foolish now. I forgot to note that I build R using a Win64
> | version of OpenBLAS (see
> | <http://www.avrahamadler.com/2014/04/20/r-3-1-0-openblas-speed-comparisons/>
> | for more). I'm certain that the speed in tcrossprod is coming from an
> | optimized compile of R and BLAS. My apologies for any confusion.
>
> That is a _feature_ and not a bug.  See eg this r-devel tread from 2005:
>
>    http://thread.gmane.org/gmane.comp.lang.r.devel/2370/
>
> Oh the good old days when Doug Bates still posted on r-devel ...
>
> Dirk
>
> --
> Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com