[petsc-dev] asm / gasm

[Fande Kong]

Mark,

Size of the index set is smaller than size of pmat in your case?  They
should be the same. I do not think we ever considered the index set has a
different size from that of Pmat.

Fande,

On Sun, Jun 26, 2016 at 7:09 AM, Mark Adams <mfadams at lbl.gov> wrote:

> GASM does assume the index set includes every equation in the matrix.  It
> should probably check this as it has pmat.
>
> I guess I can add these BC vertices in.
>
> On Sun, Jun 26, 2016 at 11:20 AM, Mark Adams <mfadams at lbl.gov> wrote:
>
>> Fande,
>>
>> An alternative debug path that may be simpler and direct, as it works
>> with master:  'make runex56' in ksp/examples/tutorials in
>> branch mark/gamg-agg-asm.
>>
>> This runs clean in valgrind (for me), I've added an ISView call to see
>> the data that causes the error, it runs on one processor, uses a 3^3 cell
>> grid (tiny), it exits cleanly with the error:
>>
>>  ....
>> 87 189
>> 88 190
>> 89 191
>> > [0]PETSC ERROR: --------------------- Error Message
>> --------------------------------------------------------------
>> > [0]PETSC ERROR: Argument out of range
>> > [0]PETSC ERROR: Index 144 at 42 location greater than max 144
>> [0]PETSC ERROR: #1 VecScatterCheckIndices_Private() line 39 in
>> /Users/markadams/Codes/petsc/src/vec/vec/utils/vscat.c
>> [0]PETSC ERROR: #2 VecScatterCreate() line 1227 in
>> /Users/markadams/Codes/petsc/src/vec/vec/utils/vscat.c
>> [0]PETSC ERROR: #3 PCSetUp_GASM() line 481 in
>> /Users/markadams/Codes/petsc/src/ksp/pc/impls/gasm/gasm.c
>>   ....
>>
>> This index 144 is very suspicious to me because there are 144 REAL dofs
>> in this test, 192 "gross" dofs, minus (48) boundary conditions. This
>> problem has just two aggregates with sizes 54 & 90 (=144). (I strip out the
>> BC vertices.)
>>
>> Maybe GASM is getting confused because I do not give it domains that
>> cover the entire mesh (I strip out BC vertices).  GASM thinks there are 144
>> equations in this system when in fact there are 192.
>>
>> It looks to me like GASM is working a space stripped of BCs but it is
>> using my indices that are in the full space.
>>
>> Mark
>>
>>
>>
>
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