Octave and LAPACK

[Samir Sharshar]

Hello all,

A few times ago, I've posted about PCA calculations which results 
differ between MacOSX and Linux Mandrake. I've continued the test with 
octave and Matlab 7.01. Data and functions were the same for all the 
trials :-)



1. Octave 2.1.64 and MatLab 7.0.1 give the same results on each 
machine. On Linux MDK 10.1, octave and matlab give the same results, on 
MacOSX octave and matlab give the same results. But the results differ 
from MacOSX and Linux MDK. I guess both octave and matlab use the host 
operating system LAPACK libraries...
2. Octave 2.1.64 on Linux MDK 10.1 and octave 2.1.57 on Debian woody 
give slightly different results
3. Octave 2.1.64 on last dev Debian running on opteron processor give a 
result slightly different of the MacOSX one and different from the 
others.

I've attached a jpeg file that I hope more explicit...

Obviously, there is a processor influence on the results... Debian 
woody and linux mdk run on GenuineIntel P4. Debian dev and Mac OSX on 
64 bits processors...

I've found on the Net a very few messages related the problem...

Any comments ?

Regards,

Samir.