On Tue, Jul 6, 2010 at 7:43 PM, Pauli Virtanen <pav@iki.fi> wrote:
Tue, 06 Jul 2010 11:53:22 -0600, Charles R Harris wrote: [clip]
Let's get this thread back to the errors. The problems seem specific to the python.org amd64 python, is that correct?
The SuperLU failures puzzle me. It should be "straightforward" C code, and I don't understand what can go wrong there. The "Factor is exactly singular" error indicates essentially means that SuperLU thinks it detects a zero pivot or something, so something seems to fail at a fairly low level.
This seems quite difficult to debug without a Win-64 at hand.
Another thing is that Gohlke's binaries are also built against MKL, and SuperLU does call BLAS routines. I wonder if something can break because of that...
@Robin: Also, for the cases where a wrong result is produced with no error: is it easy to write a small test program demonstrating this? If yes, could you write one?
Yes, below is a simple example. On my mac it works: In [10]: run -i sptest.py [-0.34841705 -0.23272338 0.27248558] [-0.34841705 -0.23272338 0.27248558] On the 64bit windows installation: In [7]: run -i spsolve_test.py [ 0.08507826 1.04401349 -1.56609783] [-0.52208434 -1.48101957 -1.56609783] In [8]: run -i spsolve_test.py [ 0.71923676 -0.12209489 -0.16069061] [-0.2827855 0.55854616 -0.16069061] import numpy as np import scipy as sp import scipy.sparse.linalg Adense = np.matrix([[ 0., 1., 1.], [ 1., 0., 1.], [ 0., 0., 1.]]) As = sp.sparse.csc_matrix(Adense) x = np.random.randn(3) b = As.matvec(x) print x print sp.sparse.linalg.spsolve(As, b)