[SciPy-User] scipy.sparse.linalg.lobpcg broken?

Pauli Virtanen pav@iki...
Wed Oct 13 14:46:50 CDT 2010

Wed, 13 Oct 2010 21:23:19 +0200, Nico Schlömer wrote:
>> It actually works for me:
> Okay, nice. I tried to run the script on another machine too, where it
> appears to work alright.

Did you use a random matrix as input? If yes, did you set the seed first, 
so that it is testing the same matrix?

> This exact same code fails on my own machine locally, meaning I'm
> probably missing some crucial dependencies (of Scipy?). Using Scipy
> 0.8.0 on Gentoo.
> Any idea what that could possibly be?

The LOBPCG code in Scipy is pretty self-contained. So I can't guess much 
else than issues with BLAS or LAPACK?

I'd maybe make a copy of lobpcg.py and put some checks in the symeig 
routine. But this is just guessing, I don't know in detail how LOBPCG 

Pauli Virtanen

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