[SciPy-user] compiler & lapack issues

[gvermeul at polycnrs-gre.fr]

Hi,

gcc-2.95.3 is an order of magnitude faster than Mandrake-8.2's gcc-2.96
in compiling the Atlas libraries. Use of 2.95.3 decreased the time
from an estimated 8 hours to far less than 1 hour on a 1 GHz AMD.

It is really worthwhile to install a minimal version of th gcc-2.95.3
compilers (no shared libraries) in /usr/local/bin.


The fact that running scipy.test() on my system dies with

.zswap:n=3
....... ** On entry to DGESDD parameter number 12 had an illegal value
[packer at venus packer]$

is related to a LAPACK issue.

Mandrake's LAPACK rpms come with a lot of patches that have been released
after "Update, Version 3.0:  May 31, 2000", see 
http://netlib2.cs.utk.edu/lapack/release_notes.html

This includes new versions of ?gesdd.f with corrected work space
calculations. Probably, the parameter checks in the corresponding
*.pyf files are out of sync with those post-latest-Update release.

What to do about this? Changing the *.pyf files will uncover errors
in LAPACK installations without those patches. On the other hand,
one one would not like to see a bridge collapse, due to an unapplied
patch, isn't it?

Gerard


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