[SciPy-user] scipy.sparse.linalg.cg not thread safe?

[Dominique Orban]

On Tue, Jan 27, 2009 at 2:11 PM, Nathan Bell <wnbell at gmail.com> wrote:
> On Mon, Jan 26, 2009 at 6:29 PM, Robert Kern <robert.kern at gmail.com> wrote:
>>
>> It's probably not threadsafe.
>>
>
> I don't know Fortran, so I can't say:
> http://projects.scipy.org/scipy/scipy/browser/trunk/scipy/sparse/linalg/isolve/iterative/CGREVCOM.f.src
>
>
> Anway, here's a pure-SciPy CG implementation (also BSD-licensed):
> http://code.google.com/p/pyamg/source/browse/trunk/pyamg/krylov/cg.py
>
> It should be a drop-in replacement for sparse.linalg.cg() and have
> comparable speed.  The only dependency is to the norm() function in
> PyAMG, but you can swipe that easily too.
>
> In time we should replace all of the Fortran implementations of the
> iterative methods with pure-Python code.  This would be a nice target
> for SciPy 0.8.

I've been interested in that and put together a basic initial package
at http://github.com/dpo/pykrylov/tree/master. The only prerequisite
should be Numpy.

For now I've been concentrating on Krylov methods that do not requite
products with the transpose, and on real linear systems.

-- 
Dominique