[Trilinos-Users] [EXTERNAL] Re: Multigrid preconditioning with 64 bit support

[Chris Jackson]

C.S.N.,

Thanks!  We'll try it out.

Chris

From: trilinos-users-bounces at software.sandia.gov [mailto:trilinos-users-bounces at software.sandia.gov] On Behalf Of C.S Natarajan
Sent: Thursday, March 07, 2013 2:39 PM
To: trilinos-users at software.sandia.gov
Subject: Re: [Trilinos-Users] [EXTERNAL] Re: Multigrid preconditioning with 64 bit support

Chris,
            I use FMG with smoothed aggregation (with ParMetis) and GMRES; Amesos-KLU is the coarse solver. The performance is very good. My coefficients vary by 5 orders of magnitude.

Cheers,
C.S.N

________________________________
From: trilinos-users-bounces at software.sandia.gov<mailto:trilinos-users-bounces at software.sandia.gov> [mailto:trilinos-users-bounces at software.sandia.gov] On Behalf Of Chris Jackson
Sent: Thursday, March 07, 2013 12:34 PM
To: trilinos-users at software.sandia.gov<mailto:trilinos-users at software.sandia.gov>
Subject: Re: [Trilinos-Users] [EXTERNAL] Re: Multigrid preconditioning with 64 bit support

As an aside, we use ML as a preconditioner for BiCGStab.  With that method, we have very slow convergence rates on strongly anisotropic Poisson problems, when compared to more isotropic ones.  If anyone knows of any special settings for ML to address that, I'd be keen to know.

Regards,

Chris Jackson

From: trilinos-users-bounces at software.sandia.gov<mailto:trilinos-users-bounces at software.sandia.gov> [mailto:trilinos-users-bounces at software.sandia.gov] On Behalf Of C.S. Natarajan
Sent: Thursday, March 07, 2013 9:44 AM
To: trilinos-users at software.sandia.gov<mailto:trilinos-users at software.sandia.gov>
Subject: Re: [Trilinos-Users] [EXTERNAL] Re: Multigrid preconditioning with 64 bit support

Thanks Mike.
On Thu, Mar 7, 2013 at 7:43 AM, Heroux, Michael A <maherou at sandia.gov<mailto:maherou at sandia.gov>> wrote:
ML does not support the "long long" map features in Epetra.  We do not plan to extent ML to support this feature, since Muelu is coming along and natively supports 64-bit types.

Mike

From: "C.S. Natarajan" <csnataraj at gmail.com<mailto:csnataraj at gmail.com>>
Date: Wednesday, March 6, 2013 11:31 PM
To: Eric Marttila <eric.marttila at thermoanalytics.com<mailto:eric.marttila at thermoanalytics.com>>
Cc: "trilinos-users at software.sandia.gov<mailto:trilinos-users at software.sandia.gov>" <trilinos-users at software.sandia.gov<mailto:trilinos-users at software.sandia.gov>>
Subject: [EXTERNAL] Re: [Trilinos-Users] Multigrid preconditioning with 64 bit support

Hi Eric,
         I don't have a problem building ML on a 64 bit platform. I am trying to solve a large problem (strongly anisotropic poisson) and was wondering if ML has 64-bit support. Just to clarify, have you used ML in conjunction with long long Epetra_Map's?
I have no problem with ML up to Trilinos 10.10 but I just upgraded to 11.03 to solve bigger problems and have started getting errors when building the preconditioner.

Thanks for the help.

C.S.N
On Wed, Mar 6, 2013 at 10:48 PM, Eric Marttila <eric.marttila at thermoanalytics.com<mailto:eric.marttila at thermoanalytics.com>> wrote:
Hi,
I'm not sure exactly what kind of 64bit support you're looking
for, but I've built and used the ML package on 64-bit linux
without any issues.
--Eric

On Wednesday, March 06, 2013 05:36:58 pm C.S. Natarajan wrote:
> Hello,
>          Is there a multigrid preconditioning package with 64
> bit support? It looks like ML is 32-bit. I am using
> trilinos11.0.3.
>
> Thanks,
> C.S.N


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