[petsc-users] MatGetDiagonal

[Hong Zhang]

The fix is in petsc-dev:
http://petsc.cs.iit.edu/petsc/petsc-dev/rev/a19846efa232

I just pushed a test of MatGetDiagonal(F,diag) for petsc Cholesky factorization
in ~petsc-dev/src/ksp/ksp/examples/tutorials/ex52.c

Do
cd ~petsc-dev
hg pull
hg update
or get the latest petsc-dev.

Run ex52 with
./ex52 -use_petsc_ch
...
Vector Object: 1 MPI processes
  type: seq
4
3.75
3.73333
3.73214
...
3.24979
3.30916
Norm of error < 1.e-12 iterations 1

Let us know if you do not get the above result.
Hong

On Thu, Aug 11, 2011 at 4:46 AM, Clemens Domanig
<clemens.domanig at uibk.ac.at> wrote:
> I checked out the dev-version today but it doesn't fix my problem.
> Is it possible that your fix is not in th dev-version?
> Thx.
>
> [0]PETSC ERROR: --------------------- Error Message
> ----------------------------
> --------
> [0]PETSC ERROR: Object is in wrong state!
> [0]PETSC ERROR: Not for factored matrix!
> [0]PETSC ERROR:
> ----------------------------------------------------------------
> --------
> [0]PETSC ERROR: Petsc Development HG revision:
> 173a9704a10394abf9048b83aebd58c4c
>
>
>
>
> Hong Zhang wrote:
>>
>> Clemens :
>> This is a bug in MatGetDiagonal_SeqSBAIJ() for cholesky factored matrix.
>> I fixed it and pushed to petsc-dev.
>> See http://www.mcs.anl.gov/petsc/petsc-as/developers/index.html
>> on how to get petsc-dev.
>>
>> Thanks for reporting the problem. Contact us if you still get problem.
>>
>> Hong
>>
>>
>>> Hi,
>>>
>>> I already talked to some of you about this in combination with some other
>>> problem, but somehow I don't get it.
>>> I want the diagonal entries of the matrix M. But my vector 'diag' is
>>> mainly
>>> full of zeros when using MatGetDiagonal().
>>> I can print 'DiagM' (VecView) where I see all the diagonal entries but I
>>> cannot access them using MatGetValue (Object is in wrong state. Not for
>>> factored matrix!).
>>> How can I get access to the diagonal?
>>> Thx - Clemens
>>>
>>>
>>> KSPCreate( coml, &kspBA);
>>> KSPGetPC( kspBA, &precond);
>>> PCSetType( precond, PCCHOLESKY);
>>> PCFactorSetMatSolverPackage( precond, MAT_SOLVER_PETSC);
>>> KSPSetOptionsPrefix( kspBA, "diag_pc_type cholesky");
>>> KSPSetFromOptions( kspBA);
>>> KSPSetOperators( kspBA, Kt, Kt, DIFFERENT_NONZERO_PATTERN);
>>> KSPSetUp( kspBA);
>>> PCFactorGetMatrix( precond, &DiagM);    //DO NOT DESTROY DiagM !!!
>>> MatGetDiagonal( DiagM, diag);
>>>
>
>