[petsc-users] DMNetworkGetEdgeRange() in parallel

[Matthew Knepley]

On Mon, Feb 23, 2015 at 8:42 AM, Miguel Angel Salazar de Troya <
salazardetroya at gmail.com> wrote:

> Thanks, that will help me. Now what I would like to have is the following:
> if I have two processors and ten edges, the partitioning results in the
> first processor having the edges 0-4 and the second processor, the edges
> 5-9. I also have a global vector with as many components as edges, 10. How
> can I partition it so the first processor also has the 0-4 components and
> the second, the 5-9 components of the vector?
>
I think it would help to know what you want to accomplish. This is how you
are proposing to do it.'

If you just want to put data on edges, DMNetwork has a facility for that
already.

  Thanks,

     Matt


> Miguel
> On Feb 23, 2015 8:08 AM, "Abhyankar, Shrirang G." <abhyshr at mcs.anl.gov>
> wrote:
>
>>  Miguel,
>>    One possible way is to store the global numbering of any edge/vertex
>> in the "component" attached to it. Once the mesh gets partitioned, the
>> components are also distributed so you can easily retrieve the global
>> number of any edge/vertex by accessing its component. This is what is done
>> in the DMNetwork example pf.c although the global numbering is not used for
>> anything.
>>
>>  Shri
>>  From: Matthew Knepley <knepley at gmail.com>
>> Date: Mon, 23 Feb 2015 07:54:34 -0600
>> To: Miguel Angel Salazar de Troya <salazardetroya at gmail.com>
>> Cc: "petsc-users at mcs.anl.gov" <petsc-users at mcs.anl.gov>
>> Subject: Re: [petsc-users] DMNetworkGetEdgeRange() in parallel
>>
>>   On Sun, Feb 22, 2015 at 3:59 PM, Miguel Angel Salazar de Troya <
>> salazardetroya at gmail.com> wrote:
>>
>>> Thanks. Once I obtain that Index Set with the routine DMPlexCreateCellNumbering()
>>> (I assume that the edges in DMNetwork correspond to cells in DMPlex) can I
>>> use it to partition a vector with as many components as edges I have in my
>>> network?
>>>
>>
>>  I do not completely understand the question.
>>
>>  If you want a partition of the edges, you can use
>> DMPlexCreatePartition() and its friend DMPlexDistribute(). What
>> are you trying to do?
>>
>>     Matt
>>
>>
>>>  Thanks
>>> Miguel
>>>
>>> On Sun, Feb 22, 2015 at 12:15 PM, Matthew Knepley <knepley at gmail.com>
>>> wrote:
>>>
>>>>  On Sun, Feb 22, 2015 at 11:01 AM, Miguel Angel Salazar de Troya <
>>>> salazardetroya at gmail.com> wrote:
>>>>
>>>>> Hi
>>>>>
>>>>>  I noticed that the routine DMNetworkGetEdgeRange() returns the local
>>>>> indices for the edge range. Is there any way to obtain the global indices?
>>>>> So if my network has 10 edges, the processor 1 has the 0-4 edges and the
>>>>> processor 2, the 5-9 edges, how can I obtain this information?
>>>>>
>>>>
>>>>  One of the points of DMPlex is we do not require a global numbering.
>>>> Everything is numbered
>>>> locally, and the PetscSF maps local numbers to local numbers in order
>>>> to determine ownership.
>>>>
>>>>  If you want to create a global numbering for some reason, you can
>>>> using DMPlexCreatePointNumbering().
>>>> There are also cell and vertex versions that we use for output, so you
>>>> could do it just for edges as well.
>>>>
>>>>    Thanks,
>>>>
>>>>       Matt
>>>>
>>>>
>>>>>  Thanks
>>>>>  Miguel
>>>>>
>>>>>  --
>>>>>  *Miguel Angel Salazar de Troya*
>>>>> Graduate Research Assistant
>>>>> Department of Mechanical Science and Engineering
>>>>> University of Illinois at Urbana-Champaign
>>>>> (217) 550-2360
>>>>> salaza11 at illinois.edu
>>>>>
>>>>>
>>>>
>>>>
>>>>  --
>>>> 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
>>>>
>>>
>>>
>>>
>>>  --
>>>  *Miguel Angel Salazar de Troya*
>>> Graduate Research Assistant
>>> Department of Mechanical Science and Engineering
>>> University of Illinois at Urbana-Champaign
>>> (217) 550-2360
>>> salaza11 at illinois.edu
>>>
>>>
>>
>>
>>  --
>> 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
>>
>>


-- 
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
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