[petsc-users] Conversion between AIJ & BAIJ

[Chung-Kan Huang]

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?

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*
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