Ciao all- I've recently run into what appears to be a known and reported problem in Atlas 3.2.1: the SSE2 optimized version is broken. This version is currently shipped with Jaunty, and is reported to still be broken in the Karmic (see bug reports below). There are numerous unassigned bug reports in launchpad which appear related to the problem, some of which are six months old:
https://bugs.launchpad.net/ubuntu/+source/atlas/+bug/363510 https://bugs.launchpad.net/ubuntu/+source/atlas/+bug/376739 https://bugs.launchpad.net/ubuntu/+source/atlas/+bug/406520 I understand that it is unusual to e-mail a dev list to call for action on a particular bug, but the failure mode here seems particularly serious. Programs that depend on the broken library compile perfectly fine, seem to return valid numerical results, and show no signs of being broken unless one compares against correct results. I fear that many of my colleagues who use Octave and other numerical tools that depend on Atlas are less in careful in such ways, and it concerns me that bogus results are probably, at this moment, being accepted as valid in research labs around the world. The way I came across the bug was by compiling the new release of Octave, 3.2.3. Both the eig and eigs functions (eigenvalue decompositions, for full and sparse matrices respectively) returned unexpected results in make check. For the set of messages related to the problem, see the following threads on the Octave list: https://www-old.cae.wisc.edu/pipermail/bug-octave/2009-September/009527.html A fix for this bug seems critical to get into Karmic, and possibly into older Ubuntu versions still supported. Cheers, Cyrus Hall -- ubuntu-motu-science mailing list [email protected] Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-motu-science
