[SciPy-dev] test failures in current trunk: sparse\linalg\isolve, and special

David Cournapeau cournape@gmail....
Sun Feb 15 21:36:37 CST 2009

On Mon, Feb 16, 2009 at 12:00 PM, Nathan Bell <wnbell@gmail.com> wrote:
> On Sun, Feb 15, 2009 at 7:53 PM, Nathan Bell <wnbell@gmail.com> wrote:
>> I can confirm the failure on Win32 and have isolated it to bicgstab.
>> I'll continue searching for the source of the error.
>> I noticed that the Windows binaries for SciPy 0.7 also have this
>> problem, but the test has been marked as a known failure.  Was this
>> bug ever reported?

I should have checked it was, it is more than likely that I forgot it.

> The problem seems to be that when bicgstab enters the Fortran function
> BICGSTABREVCOM it dies a horrible death and returns INFO=-10
> signifying breakdown of the algorithm.  This doesn't make sense,
> because the calling function hasn't really provided the Fortran side
> with any real data except the right hand side (b) and the initial
> iterate (x) which happens to be 0 in this case.  I don't know Fortran,
> but I believe the condition on 269 should be false since (I think)
> WORK(1,RTLD) and WORK(1,R) are the same vector (both copies of b)
> which, in the tests, is chosen randomly.

Without going into the details of the code, it is strange that the
same code works on linux and mac os x and not on windows. Since it
happends within fortran, it may be a fortran compiler bug. When I will
have more time, I will test it with gfortran,



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