linear_partitioner.c

一个用来实现偏微分方程中网格的计算库

// $Id: linear_partitioner.C 2789 2008-04-13 02:24:40Z roystgnr $

// The libMesh Finite Element Library.
// Copyright (C) 2002-2007  Benjamin S. Kirk, John W. Peterson
  
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
  
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
  
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA



// C++ Includes   -----------------------------------

// Local Includes -----------------------------------
#include "mesh_base.h"
#include "linear_partitioner.h"
#include "libmesh_logging.h"
#include "elem.h"


// ------------------------------------------------------------
// LinearPartitioner implementation
void LinearPartitioner::_do_partition (MeshBase& mesh,
				       const unsigned int n)
{
  libmesh_assert (n > 0);

  // Check for an easy return
  if (n == 1)
    {
      this->single_partition (mesh);
      return;
    }
  
  // Create a simple linear partitioning
  {
    START_LOG ("partition()", "LinearPartitioner");
    
    const unsigned int n_active_elem = mesh.n_active_elem();
    const unsigned int blksize       = n_active_elem/n;
    
    unsigned int e = 0;

    MeshBase::element_iterator       elem_it  = mesh.active_elements_begin();
    const MeshBase::element_iterator elem_end = mesh.active_elements_end(); 

    for ( ; elem_it != elem_end; ++elem_it)
      {
	if ((e/blksize) < n)
          {
            Elem *elem = *elem_it;
	    elem->processor_id() = e/blksize;
          }
	else
          {
            Elem *elem = *elem_it;
	    elem->processor_id() = 0;
	    elem = elem->parent();
	  }
	
	e++;
      }
    
    STOP_LOG ("partition()", "LinearPartitioner");
  }
}