ReadPartFile.cpp

read partition file created by a Zoltan process, that used the global ids for identification of entities

/** @example ReadPartFile.cpp
 *
 * read partition file created by a Zoltan process, that used the global ids for
 * identification of entities
 */
 
#include "moab/Core.hpp"
#include <iostream>
#include <fstream>
 
using namespace moab;
using namespace std;
 
#ifndef MESH_DIR
#define MESH_DIR "."
#endif
 
// Note: change the file name below to test a trivial "No such file or directory" error
string test_file_name = string( MESH_DIR ) + string( "/3k-tri-sphere.vtk" );
string part_file_name;
int nparts;
int main( int argc, char** argv )
{
 // Get MOAB instance
 Interface* mb = new( std::nothrow ) Core;
 if( NULL == mb ) return 1;
 
 // Need option handling here for input filename
 if( argc > 4 )
 {
 // User has input a mesh file
 test_file_name = argv[1];
 part_file_name = argv[2];
 nparts = atoi( argv[3] );
 }
 else
 {
 cerr << " usage is " << argv[0] << " <input file> <part file> <#parts> <output file> \n";
 exit( 0 );
 }
 ifstream inFile;
 inFile.open( part_file_name.c_str() );
 if( !inFile )
 {
 cerr << "Unable to open file " << part_file_name << "\n";
 exit( 1 ); // call system to stop
 }
 // Load the mesh from file
 ErrorCode rval = mb->load_mesh( test_file_name.c_str() );MB_CHK_ERR( rval );
 
 // Get sets entities, by type
 Range sets;
 rval = mb->get_entities_by_type( 0, MBENTITYSET, sets );MB_CHK_ERR( rval );
 
 // Output the number of sets
 cout << "Number of sets is " << sets.size() << endl;
 // remove the sets that have a PARALLEL_PARTITION tag
 
 Tag tag;
 rval = mb->tag_get_handle( "PARALLEL_PARTITION", tag );MB_CHK_ERR( rval );
 
 int i = 0;
 int num_deleted_sets = 0;
 for( Range::iterator it = sets.begin(); it != sets.end(); it++, i++ )
 {
 EntityHandle eh = *it;
 // cout << " set :" << mb->id_from_handle(eh) <<"\n";
 int val = -1;
 rval = mb->tag_get_data( tag, &eh, 1, &val );
 if( val != -1 )
 {
 num_deleted_sets++;
 rval = mb->delete_entities( &eh, 1 ); // delete the set, we will have a new partition soon
 }
 }
 if( num_deleted_sets ) cout << "delete " << num_deleted_sets << " existing partition sets, and create new ones \n";
 Range cells; // get them by dimension 2!
 rval = mb->get_entities_by_dimension( 0, 2, cells );MB_CHK_ERR( rval );
 EntityHandle* psets = new EntityHandle[nparts];
 for( int i = 0; i < nparts; i++ )
 {
 rval = mb->create_meshset( MESHSET_SET, psets[i] );MB_CHK_ERR( rval );
 rval = mb->tag_set_data( tag, &( psets[i] ), 1, &i );MB_CHK_ERR( rval );
 }
 
 for( Range::iterator it = cells.begin(); it != cells.end(); it++ )
 {
 int part;
 EntityHandle eh = *it;
 inFile >> part;
 rval = mb->add_entities( psets[part], &eh, 1 );MB_CHK_ERR( rval );
 }
 mb->write_file( argv[4] );
 
 delete mb;
 
 return 0;
}