[Rcpp-devel] [Lme4-authors] got a minute to answer dumb questions about throw/catch in Rcpp?

[Dirk Eddelbuettel]

On 4 January 2011 at 14:20, Ben Bolker wrote:
| On 11-01-04 01:35 PM, Douglas Bates wrote:
[...]
| > Well, it's the version of the accelerated BLAS/Lapack code that is
| > more at fault than Lapack itself.  As this occurs on Mac OS X and not
| > on other operating systems one test would be to build a OS X version
| > of R that used the reference BLAS and the reference Lapack code
| > shipped with R (i.e. use the --without-blas and --without-lapack
| > flags) and see if the problem persists.
| 
|   Just to clarify:
| 
|   this is *not* happening on MacOS, it's happening on Ubuntu 10.10
| (32-bit).
| 
|   Just to make things even murkier, I have tried building R-devel
| (2.13.0) both with BLAS and LAPACK and without and ... it seems to work
| both ways.  I will dig out R 2.12.1 source code and try compiling with
| and without (my current (CRAN Ubuntu repository) version has
| 
| bolker at ubuntu-10:~$ R CMD config LAPACK_LIBS
| - -llapack
| bolker at ubuntu-10:~$ R CMD config BLAS_LIBS
| - -lblas
| 
|  i.e. system libraries)

Actually, not really. This is sometimes a suble point of confusion.

On Debian and Ubuntu, -llapack -lblas still leaves you with the choice of
swapping the actual LAPACK and BLAS implementations.  That happens to be a
massive feature and not a bug. It is setup in such a way that different
library packages can provide different _implementations_ of the standardised
LAPACK/BLAS _interfaces_.  So you could be running any on of basic
(unoptimised), Atlas, Goto, or MKL.

[ And that happens to be the setup I describe and use in the BLAS/GPU
benchmarking package/paper/vignette in my CRAN package 'gcbd'; I also tried
to explain the underlying issue in the paper/vignette in some detail. ]

Doug actually touches upon that above.  If you have test script that fails
for you on Ubuntu, then I could try to take a look and swap LAPACK/BLAS
libraries to see if it makes a difference.

Dirk

-- 
Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com