[Rd] lapack tests fail -- is this something to worry about?

[Prof Brian Ripley]

I think it is just that you should bear in mind that your system is less 
accurate than a more modern one (and lots of compiler bugs have been fixed 
since gcc 3.2.3).

[I am surprised your sysadmins are happy running an OS that is lacking so 
many of the security features of current Linuxen.  Ours are not!]


On Thu, 19 Oct 2006, Armstrong, Whit wrote:

> I see the comment here about some 64bit combinations failing.
>
> Well, my configuration fails.  Is this really something to worry about?
>
> for R-patched:
> fi1->cat SVN-REVISION
> Revision: 39576
> Last Changed Date: 2006-10-03
> fi1->
>
>
>> ## failed for some 64bit-Lapack-gcc combinations:
>> sm <- cbind(1, 3:1, 1:3)
>> eigenok(sm, eigen(sm))
> Error: abs(A %*% V - V %*% diag(lam)) < Eps is not all TRUE
>> eigenok(sm, eigen(sm, sym=FALSE))
> Error: abs(A %*% V - V %*% diag(lam)) < Eps is not all TRUE
>>
>
>
> I'm not using a nonstandard blas or lapack, just the ones included in R.
>
>
> Here is my system information:
>
> fi1->gcc --version
> gcc (GCC) 3.2.3 20030502 (Red Hat Linux 3.2.3-47)
> Copyright (C) 2002 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.  There is
> NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
> PURPOSE.
>
> fi1->uname -a
> Linux fi1.nyc.office.hcmny.com 2.4.21-32.ELsmp #1 SMP Fri Apr 15
> 21:03:28 EDT 2005 x86_64 x86_64 x86_64 GNU/Linux
> fi1->
>
>
> This is RHEL v3.  I know gcc 3.2.3 is old, but I don't have root, and
> our admins are not crazy about changing 1 system to accommodate 1 user,
> so I'm happy to ignore the test failure if it's not something to worry
> about.  I'm not using lapack routines in my code, but I don't know to
> what extent R makes use of lapack internally.
>
> Can anyone give me the skinny on whether this test failure really
> matters?
>
> Thanks,
> Whit
>
>
>
>
>
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>

-- 
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