[petsc-users] Conversion between AIJ & BAIJ

[Matthew Knepley]

On Wed, Jan 21, 2015 at 2:07 PM, Chung-Kan Huang <ckhuangf at gmail.com> wrote:

>
> On Wed, Jan 21, 2015 at 2:01 PM, Matthew Knepley <knepley at gmail.com>
> wrote:
>
>> On Wed, Jan 21, 2015 at 1:55 PM, Chung-Kan Huang <ckhuangf at gmail.com>
>> wrote:
>>
>>>
>>> On Wed, Jan 21, 2015 at 1:44 PM, Matthew Knepley <knepley at gmail.com>
>>> wrote:
>>>
>>>> On Wed, Jan 21, 2015 at 1:40 PM, Chung-Kan Huang <ckhuangf at gmail.com>
>>>> wrote:
>>>>
>>>>> Then A & AB are not longer the same matrix.  They become complete two
>>>>> individuals aren't they?
>>>>> If I do whatever to AB after AB is created the A is still the same old
>>>>> A and not going to be affected by the operations I do to AB.
>>>>>
>>>>
>>>> Yes.
>>>>
>>>>
>>>>>
>>>>> What I am really looking for is a way to create two interfaces (one as
>>>>> AIJ and one as BAIJ) but they both refer to the same matrix.
>>>>>
>>>>
>>>> Why would you ever want this? Why not just using BAIJ?
>>>>
>>> As I mentioned in the beginning.  There are parts of the code gets
>>> benifit when AIJ is used and the other part gets benifit  if BAIJ is used.
>>>
>>> For instance,
>>>
>>> I'd like to use MatSetValuesBlocked but I also want to use ilu
>>> constructed by AIJ instead of BAIJ (our experience found ilu from BAIJ
>>> behaves funny sometimes.
>>>
>>
>> If the blocks truly are dense, then ILU(0) is identical on both.
>>
>
> Unfortunately the life is not that easy.  The blocks are spares and we
> found ILU(1) works better for our case.
> And besides that is not the only reason I want to have AIJ & BAIJ
> interfaces, we have some code management issue and I am looking for short
> cut to unite them.
>
> So go back to the original question the short answer is no way?
>

Yes, it would not make sense.

What problem are you using ILU(1) for?

  Thanks,

     Matt


> Thanks,
>
> Kan
>
>>
>>   Matt
>>
>>
>>> Thanks,
>>>
>>> Kan
>>>
>>>>
>>>>   Thanks,
>>>>
>>>>       Matt
>>>>
>>>>
>>>>> Thanks,
>>>>>
>>>>> Kan
>>>>> On Wed, Jan 21, 2015 at 1:20 PM, Matthew Knepley <knepley at gmail.com>
>>>>> wrote:
>>>>>
>>>>>> On Wed, Jan 21, 2015 at 12:56 PM, Chung-Kan Huang <ckhuangf at gmail.com
>>>>>> > wrote:
>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> So if I do
>>>>>>>
>>>>>>> Mat A, AB;
>>>>>>> MatCreateAIJ(comm,m,n,M,N,d_nz, d_nnz,o_nz, o_nnz, &A);
>>>>>>> MatConvert(A, MATBAIJ, MAT_INITAL_MATRIX, &AB);
>>>>>>> MatSetBlockSize(AB, bs)
>>>>>>> I can create AB as a BAIJ with block size of bs from A which is a
>>>>>>> AIJ matrix.
>>>>>>>
>>>>>>> So from this point I can use both A and AB and they will mean the
>>>>>>> same matrix. Am I right?
>>>>>>>
>>>>>>
>>>>>> Yes
>>>>>>
>>>>>>
>>>>>>> At the end of the program do I only destory one of them or both?
>>>>>>>
>>>>>>
>>>>>> Both
>>>>>>
>>>>>>
>>>>>>> Do I need to worry about anything in terms of memory penalty?
>>>>>>>
>>>>>>
>>>>>> It is twice the memory. Its another matrix.
>>>>>>
>>>>>> Did you catch when Jed said you could jsut create the BAIJ up front?
>>>>>>
>>>>>>   Thanks,
>>>>>>
>>>>>>     Matt
>>>>>>
>>>>>>
>>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>> Kan
>>>>>>>
>>>>>>>
>>>>>>> On Tue, Jan 20, 2015 at 4:39 PM, Barry Smith <bsmith at mcs.anl.gov>
>>>>>>> wrote:
>>>>>>>
>>>>>>>>
>>>>>>>>   You can do a MatConvert() (requires another copy of the matrix)
>>>>>>>> for the parts that benefit from BAIJ.
>>>>>>>>
>>>>>>>>   Barry
>>>>>>>>
>>>>>>>> > On Jan 20, 2015, at 4:33 PM, Chung-Kan Huang <ckhuangf at gmail.com>
>>>>>>>> wrote:
>>>>>>>> >
>>>>>>>> > Hi,
>>>>>>>> >
>>>>>>>> > Does PETSc provide means for conversion between AIJ & BAIJ.
>>>>>>>> >
>>>>>>>> > My matrix is created as AIJ because it makes life easy for most
>>>>>>>> part of the applications but some part of applications actually get some
>>>>>>>> benefits with BAIJ.  So I wonder if a matrix can exist as two idenfities
>>>>>>>> and I can use either format depend on which one is more convenient at run
>>>>>>>> time.
>>>>>>>> >
>>>>>>>> > So in my case the block size is fixed and identical for all
>>>>>>>> blocks.
>>>>>>>> >
>>>>>>>> >
>>>>>>>> > Thanks,
>>>>>>>> >
>>>>>>>> >
>>>>>>>> > Kan
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>>
>>>>>>> *Cheers*
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> What most experimenters take for granted before they begin their
>>>>>> experiments is infinitely more interesting than any results to which their
>>>>>> experiments lead.
>>>>>> -- Norbert Wiener
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>>
>>>>> *Cheers*
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> What most experimenters take for granted before they begin their
>>>> experiments is infinitely more interesting than any results to which their
>>>> experiments lead.
>>>> -- Norbert Wiener
>>>>
>>>
>>>
>>>
>>> --
>>>
>>> *Cheers*
>>>
>>
>>
>>
>> --
>> What most experimenters take for granted before they begin their
>> experiments is infinitely more interesting than any results to which their
>> experiments lead.
>> -- Norbert Wiener
>>
>
>
>
> --
>
> *Cheers*
>



-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20150121/f35630a1/attachment-0001.html>