[Trilinos-Users] problem using amesos

[Thornquist, Heidi K]

Hi MM,

I've used the Amesos KLU solver for several years in our circuit
simulation code and have occasionally
come across the singular matrix error (-22).  In many cases the matrix is
truly close to singular, but
as a sanity check I try to use SuperLU on the same matrices to see if KLU
is just being picky.  Given the
fact that your application is FE based, you might want to give SuperLU a
shot.  It's easy to build and
integrate into the Amesos interface.

Thanks,
Heidi

---
Heidi K. Thornquist
Senior Member of Technical Staff
Electrical Systems Modeling
Sandia National Laboratories
P.O. Box 5800, MS 0316
Albuquerque, NM  87185-0316
Phone: (505)284-8426
Fax:   (505)284-5451





On 3/28/11 4:56 AM, "Massimiliano Martinelli"
<massimiliano.martinelli at gmail.com> wrote:

>Hi,
>
>I'm trying to use Amesos (through Stratimikos) in my FE code but I have
>a problem.
>
>Using AztecOO to solve the linear system, everything is working well,
>but if I use Amesos I obtain the following error message:
>
>terminate called after throwing an instance of
>'Thyra::CatastrophicSolveFailure'
>   what():  
>/Users/max/Downloads/trilinos-10.6.4-Source/packages/stratimikos/adapters/
>amesos/src/Thyra_AmesosLinearOpWithSolveFactory.cpp:299:
>
>Throw number = 1
>
>Throw test that evaluated to true: 0!=err
>
>Error, NumericFactorization() on amesos solver of type 'Amesos_Klu'
>returned error code -22!
>make: *** [run_serial] Abort trap
>
>
>Looking into Amesos implementation, code -22 means that my matrix is
>numerically singular, but I know that my matrix is NOT
>singular...(AztecOO give me the correct results)
>
>Have you any any idea why this strange behaviour?
>
>Thank you in advance.
>
>MM
>
>-- 
>Massimiliano Martinelli, PhD.
>IMATI-CNR Pavia
>massimiliano.martinelli at gmail.com
>
>
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