[petsc-users] Partitioning in DMNetwork

2015-02-26 Thread Miguel Angel Salazar de Troya
Hi

In DMNetwork we have edges and vertices and we can add an arbitrary number
of variables to both edges and vertices. When the partitioning is carried
out, is this done according to the number of edges and vertices or the
variables? Say for example, that we assigned a very large number of
variables to the first edge, a number much greater than the total number of
edges or vertices. After the partitioning, the processor that contains that
edge with many variables would have a very large portion of the global
vector, wouldn't it?

This case is hypothetical and something to avoid, but, could it happen?
Would the partitioning be made in some other way to avoid this load
unbalance?

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
salaz...@illinois.edu


Re: [petsc-users] Partitioning in DMNetwork

2015-02-26 Thread Matthew Knepley
On Thu, Feb 26, 2015 at 11:33 AM, Miguel Angel Salazar de Troya 
salazardetr...@gmail.com wrote:

 Hi

 In DMNetwork we have edges and vertices and we can add an arbitrary number
 of variables to both edges and vertices. When the partitioning is carried
 out, is this done according to the number of edges and vertices or the
 variables? Say for example, that we assigned a very large number of
 variables to the first edge, a number much greater than the total number of
 edges or vertices. After the partitioning, the processor that contains that
 edge with many variables would have a very large portion of the global
 vector, wouldn't it?

 This case is hypothetical and something to avoid, but, could it happen?
 Would the partitioning be made in some other way to avoid this load
 unbalance?


We can do weighted partitioning. We have not done it yet because in my
experience the partitioners
are quite fragile with respect to the weights and also the weighting has to
be very coarse-grained.
However, if you have something that really needs it, we can do it.

  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
 salaz...@illinois.edu




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What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
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-- Norbert Wiener