[Numpy-discussion] Unhandled floating point exception running test in numpy-1.0.3 and svn 3875

rex rex@nosyntax....
Sun Jun 24 10:55:27 CDT 2007


Charles R Harris <charlesr.harris@gmail.com> [2007-06-24 06:22]:
> 
> 
> On 6/23/07, rex <rex@nosyntax.com> wrote:
> 
>     Stefan van der Walt <stefan@sun.ac.za> [2007-06-23 15:06]:
>>
>> On Sat, Jun 23, 2007 at 07:35:35PM +0000, John Ollinger wrote:
>>> I have just been updating our version of Python, numpy and
>>> scipy and have run into a floating point exception that crashes
>>> Python when I test the release.
> 
> What do you mean by crash? Is anything printed? Do older versions of numpy
> still work?

John needs to respond to this.
 
>>> I am running gcc 3.3.1 on SuSe Linux 2.4.21-144-smp4G.  The error
>>> first occurred with numpy-1.0.3.  I downloaded svn 3875 when I then
>>> read the scipy web page and installed the latest subversion. The
>>> test command I am using is >>> python -c 'import numpy;
>>> numpy.test(level=1,verbosity==2)' >>> and occurs during the matvec
>>> test.  This test uses rand to generate 10x8 and 8x1
>>
>> It may be worth checking whether the new version of numpy is picked
>> up.  You can do that using
>>
>> import numpy as N
>     > print N.__version__
>     >
>     > We have a build slave with a very similar setup to yours (see
>     > http://buildbot.scipy.org ) and everything seems to be fine.
> 
>     It's somewhat different:
>     SUSE 10.2
>     Core 2 Duo 32-bit
>     Kernel 2.6.18.2-34-default
>     gcc version 4.1.2 20061115 (prerelease) (SUSE Linux)
>     Python 2.5 (r25:51908, Nov 27 2006
>     print N.__version__
>     1.0.4.dev3868
>     python -c 'import numpy; numpy.test(level=1,verbosity=2)'
>     [...]
>     Ran 590 tests in 0.473s
> 
> 
> Do you use Atlas? If so, did you compile it yourself or did you use a package?
> There is a bug in some older 64 bit Atlas packages running on newer intel
> hardware that generates illegal instruction exceptions and I am wondering if
> you may have found a new 32 bit bug. One way to check this is to multiply two
> big matrices together. There are many paths through Atlas, so the known bug is
> not encountered in all matrix multiplications, and perhaps not for all floating
> values either.

The above system is running the http://buildbot.scipy.org/ buildbot with
no errors. It doesn't appear to build ATLAS. It's John's older system
(gcc 3.3.1 2.4.21-144-smp4G) -- AFAIK, 2.4.21 was used in SUSE
9.0. Current version is 10.2 -- that is throwing an error, not mine.

-rex


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