Johan Hake wrote:
> Hello Marc!
>
>> here's a little patch I did to handle the change in MatInfo from
>> Petsc-3.0.0 (which no longer includes global sizes...this is handled
>> by MatGetSize)
>
> Ok.
>
>> I believe this bit of code has the same functionality as your
>> original code (whether that test is appropriate for determining the
>> same NonZeroStructure, I'm not sure)
>
> Thanks!
>
>> // mspieg: matinfo no longer includes sizes in petsc-dev
>> MatInfo this_info, other_info;
>> MatGetInfo(*(this->A), MAT_GLOBAL_SUM, &this_info);
>> MatGetInfo(*A.mat(), MAT_GLOBAL_SUM, &other_info);
>> PetscInt this_m, this_n, other_m, other_n;
>> MatGetSize(*(this->A),&this_m,&this_n);
>> MatGetSize(*(this->A),&other_m,&other_n);
>>
>> return this_info.nz_allocated == other_info.nz_allocated && \
>> this_n == other_n && \
>> this_m == other_m;
>
> However as you say I am not sure this is enough to determine the same nonzero
> patter. As a side note we also store the size of the global matrix so we
> probably do not have to call PETSc for this.
>
> Should we include more comparisions from the MatInfo, memory, blocksize?
>
This should be left to the user,
void PETScMatrix::axpy(double a, const GenericMatrix& A, bool
same_nonzero_pattern = false);
The test for the non-zero pattern doesn't look robust to me. I would
expect that if there was an efficient, robust test to compare sparsity
patterns that PETSc would perform this.
Also, there is a problem with the code in PETScMatrix::axpy(..). Instead of
dolfin_assert(sameNonzeroPattern(*AA));
MatAXPY(*(this->A), a, *AA->mat(), SAME_NONZERO_PATTERN);
it should be
if (sameNonzeroPattern(*AA))
MatAXPY(*(this->A), a, *AA->mat(), SAME_NONZERO_PATTERN);
else
MatAXPY(*(this->A), a, *AA->mat(), DIFFERENT_NONZERO_PATTERN);
Garth
> Johan
>
>> cheers
>> marc
>>
>> On Mar 4, 2009, at 2:50 PM, Johan Hake wrote:
>>> On Wednesday 04 March 2009 20:16:56 Garth N. Wells wrote:
>>>> Johan Hake wrote:
>>>>> On Wednesday 04 March 2009 12:46:10 DOLFIN wrote:
>>>>>> One or more new changesets pushed to the primary dolfin repository.
>>>>>> A short summary of the last three changesets is included below.
>>>>>>
>>>>>> changeset: 5791:7b24d1479dff485f4db0ba38c2e28984a0a3cf46
>>>>>> tag: tip
>>>>>> user: "Garth N. Wells <[email protected]>"
>>>>>> date: Wed Mar 04 11:33:23 2009 +0000
>>>>>> files: dolfin/la/PETScKrylovSolver.cpp
>>>>>> dolfin/la/PETScKrylovSolver.h dolfin/la/PETScMatrix.cpp
>>>>>> dolfin/la/PETScMatrix.h
>>>>>> dolfin/la/PETScPreconditioner.cpp dolfin/la/PETScPreconditioner.h
>>>>>> description:
>>>>>> Fixes for PETSc 2.3.3 compatibility.
>>>>> This commit broke the linear algebra test for PETSc matrices. The
>>>>> check
>>>>> for the sparsity pattern is commented out, and en error is raised
>>>>> instead. Is it not possible to check the non zero pattern for PETSc
>>>>> matrices in 3.0?
>>>> The same check doesn't work with PETSc 3.0 because of changes to
>>>> MatInfo.
>>> Ok.
>>>
>>>> The check is not pretty so we should find a better solution if this
>>>> function is required.
>>> I think it would be nice to have it, as PETSc can do some
>>> optimalizations if
>>> two matrices have the same pattern.
>>>
>>>> There is a PETSc function
>>>> MatGetSeqNonzeroStructure which may help, but I haven't had time
>>>> to look
>>>> at it.
>>> Haven't looked to deep into MatGetSeqNonzeroStructure. But it
>>> sounds like it
>>> gives the nonzero sparsity pattern which we really are not
>>> interested in.
>>>
>>>> Why is the function PETScMatrix::sameNonzeroPattern required? It's
>>>> not
>>>> implemented for all backends.
>>> When I implemented the axpy function I added this test. I do check
>>> the nonzero
>>> pattern for EpetraMatrices too, but there I only do it once, so no
>>> extra
>>> function.
>>>
>>> I think we should be able to still use the MatInfo structure, but
>>> maybe some
>>> guidence from the PETSc developers could help?
>>>
>>> Johan
>>>
>>>> Garth
>>>>
>>>>> Johan
>>>>>
>>>>>> changeset: 5790:05d6f03e87a8bb33cc5dc55add40e8de1c6ebfd0
>>>>>> user: "Garth N. Wells <[email protected]>"
>>>>>> date: Wed Mar 04 11:21:41 2009 +0000
>>>>>> files: dolfin/la/PETScKrylovMatrix.cpp
>>>>>> dolfin/la/PETScKrylovSolver.cpp dolfin/la/PETScKrylovSolver.h
>>>>>> dolfin/la/PETScLUSolver.cpp dolfin/la/PETScMatrix.cpp
>>>>>> dolfin/la/PETScMatrix.h dolfin/la/PETScPreconditioner.cpp
>>>>>> dolfin/la/PETScPreconditioner.h description:
>>>>>> PETSc 3 updates.
>>>>>>
>>>>>>
>>>>>> changeset: 5789:3abcc647c6141cc4b2fd035cc417eedf80872ae7
>>>>>> user: "Garth N. Wells <[email protected]>"
>>>>>> date: Wed Mar 04 10:45:44 2009 +0000
>>>>>> files: dolfin/la/PETScKrylovSolver.cpp
>>>>>> description:
>>>>>> Some updates for PETSc 3.
>>>>>>
>>>>>> -------------------------------------------------------------------
>>>>>> ---
>>>>>> For more details, visit http://www.fenics.org/hg/dolfin
>>>>>> _______________________________________________
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>>>>>> http://www.fenics.org/mailman/listinfo/dolfin-dev
>>>>> _______________________________________________
>>>>> DOLFIN-dev mailing list
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>>> _______________________________________________
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>> ----------------------------------------------------
>> Marc Spiegelman
>> Lamont-Doherty Earth Observatory
>> Dept. of Applied Physics/Applied Math
>> Columbia University
>> http://www.ldeo.columbia.edu/~mspieg
>> tel: 845 704 2323 (SkypeIn)
>> ----------------------------------------------------
>
>
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