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------- Forwarded message -------
From: "Mads Hoel" <[EMAIL PROTECTED]>
To: "Matthew Knepley" <[EMAIL PROTECTED]>
Cc:
Subject: Re: [DOLFIN-dev] Solving eigenvalue problems with dolfin
Date: Wed, 28 Nov 2007 23:21:02 +0100

On Tue, 27 Nov 2007 16:35:52 +0100, Matthew Knepley <[EMAIL PROTECTED]>
wrote:

> On Nov 27, 2007 9:33 AM, Anders Logg <[EMAIL PROTECTED]> wrote:
>> On Tue, Nov 27, 2007 at 04:30:43PM +0100, Thomas Witkowski wrote:
>> > Hi,
>> >
>> > I want to use dolfin for solving eigenvalue problems. I've installed
>> > dolfin 0.7.1 with petsc and slepc. The matrix, for which the  
>> eigenvalues
>> > should be computed, is defined in the following way:
>> >
>> > PETScMatrix C(TS, TS);
>> > C.set(.....);
>> > C.set(.....);
>>
>> Try calling
>>
>>   C.apply();
>
> Why change the name from assemble()? You even used it in your  
> description,
> and apply() is easily confused with operator application.

Perhaps they wanted to avoid confusion with assembling contributions from
the element matrices, atleast I found that confusing when I started out
with PETSc. The PETSc manual often refer to assembling the matrices,
refering to MatAssemblyBegin/MatAssemblyEnd(), that has to be done once
the precaching of values are done. But I agree, apply might be equally
confusing. What about the name applyChanges? Or perhaps processValues?

Then again, not using the name assemble might be confusing if one knows
that it is a PETSc matrix one is working with.

>
>   Matt
>
>> after the set functions.
>>
>> PETSc needs to "assemble" the changes you made when calling set()
>> before you can do anything with the matrix.
>>
>> --
>> Anders
>>
>>
>>
>> > Now, when I'm trying to solve the problem with:
>> >
>> >  SLEPcEigenvalueSolver esolver;
>> >  esolver.solve(C);
>> >
>> > I get the following error message:
>> >
>> >
>> > [0]PETSC ERROR: --------------------- Error Message
>> > ------------------------------------
>> > [0]PETSC ERROR: Object is in wrong state!
>> > [0]PETSC ERROR: Not for unassembled matrix!
>> > [0]PETSC ERROR:
>> >  
>> ------------------------------------------------------------------------
>> > [0]PETSC ERROR: Petsc Release Version 2.3.3, Patch 8, Fri Nov 16
>> > 17:03:40 CST 2007 HG revision:  
>> 414581156e67e55c761739b0deb119f7590d0f4b
>> > [0]PETSC ERROR: See docs/changes/index.html for recent updates.
>> > [0]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
>> > [0]PETSC ERROR: See docs/index.html for manual pages.
>> > [0]PETSC ERROR:
>> >  
>> ------------------------------------------------------------------------
>> > [0]PETSC ERROR: ./mass on a linux-gnu named ... by witkowsk Tue Nov 27
>> > 16:17:51 2007
>> > [0]PETSC ERROR: Libraries linked from
>> > /u/witkowski/local/petsc-2.3.3-p8/lib/linux-gnu-cxx
>> > [0]PETSC ERROR: Configure run at Tue Nov 27 11:24:27 2007
>> > [0]PETSC ERROR: Configure options --with-mpi-dir=/u/witkowski/local
>> > --with-clanguage=cxx --download-hypre=yes --with-hypre=1
>> > --download-umfpack=yes --with-umfpack=1 --with-shared=0
>> > [0]PETSC ERROR:
>> >  
>> ------------------------------------------------------------------------
>> > [0]PETSC ERROR: MatMult() line 1616 in src/mat/interface/matrix.c
>> > [0]PETSC ERROR: STApply_Shift() line 30 in src/st/impls/shift/shift.c
>> > [0]PETSC ERROR: STApply() line 49 in src/st/interface/stsolve.c
>> > [0]PETSC ERROR: EPSBasicArnoldi() line 86 in  
>> src/eps/impls/arnoldi/arnoldi.c
>> > [0]PETSC ERROR: EPSSolve_KRYLOVSCHUR() line 91 in
>> > src/eps/impls/krylovschur/krylovschur.c
>> > [0]PETSC ERROR: EPSSolve() line 71 in src/eps/interface/solve.c
>> > Eigenvalue solver (krylovschur) converged in 1 iterations.
>> >
>> >
>> > What does it meen? And what have I made wrong?
>> >
>> > Regards,
>> >
>> > Thomas
>> > _______________________________________________
>> > DOLFIN-dev mailing list
>> > [email protected]
>> > http://www.fenics.org/mailman/listinfo/dolfin-dev
>> _______________________________________________
>> DOLFIN-dev mailing list
>> [email protected]
>> http://www.fenics.org/mailman/listinfo/dolfin-dev
>>
>
>
>



-- 
Mads Hoel
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