HelloMOAB.cpp

Description: read a mesh, get the entities.
HelloMOAB is a simple test file which is used to read meshes from VTK file and test how many entities there are.
To run: ./HelloMOAB [meshfile]
(default values can run if users don't specify a mesh file)

/** @example HelloMOAB.cpp
 * Description: read a mesh, get the entities.\n
 * HelloMOAB is a simple test file which is used to read meshes from VTK file and test how many
 * entities there are.\n
 *
 * To run: ./HelloMOAB [meshfile]\n
 * (default values can run if users don't specify a mesh file)
 */
 
#include "moab/Core.hpp"
#include <iostream>
 
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" );
 
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 > 1 )
 {
 // User has input a mesh file
 test_file_name = argv[1];
 }
 
 // Load the mesh from vtk file
 ErrorCode rval = mb->load_mesh( test_file_name.c_str() );MB_CHK_ERR( rval );
 
 // Get verts entities, by type
 Range verts;
 rval = mb->get_entities_by_type( 0, MBVERTEX, verts );MB_CHK_ERR( rval );
 
 // Get edge entities, by type
 Range edges;
 rval = mb->get_entities_by_type( 0, MBEDGE, edges );MB_CHK_ERR( rval );
 
 // Get faces, by dimension, so we stay generic to entity type
 Range faces;
 rval = mb->get_entities_by_dimension( 0, 2, faces );MB_CHK_ERR( rval );
 
 // Get regions, by dimension, so we stay generic to entity type
 Range elems;
 rval = mb->get_entities_by_dimension( 0, 3, elems );MB_CHK_ERR( rval );
 
 // Output the number of entities
 cout << "Number of vertices is " << verts.size() << endl;
 cout << "Number of edges is " << edges.size() << endl;
 cout << "Number of faces is " << faces.size() << endl;
 cout << "Number of elements is " << elems.size() << endl;
 
 delete mb;
 
 return 0;
}