HelloMOAB.cpp

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    1 /** @example HelloMOAB.cpp
    2  * Description: read a mesh, get the entities.\n
    3  * HelloMOAB is a simple test file which is used to read meshes from VTK file and test how many
    4  * entities there are.\n
    5  *
    6  * To run: ./HelloMOAB [meshfile]\n
    7  * (default values can run if users don't specify a mesh file)
    8  */
    9  
   10 #include "moab/Core.hpp"
   11 #include <iostream>
   12  
   13 using namespace moab;
   14 using namespace std;
   15  
   16 #ifndef MESH_DIR
   17 #define MESH_DIR "."
   18 #endif
   19  
   20 // Note: change the file name below to test a trivial "No such file or directory" error
   21 string test_file_name = string( MESH_DIR ) + string( "/3k-tri-sphere.vtk" );
   22  
   23 int main( int argc, char** argv )
   24 {
   25     // Get MOAB instance
   26     Interface* mb = new( std::nothrow ) Core;
   27     if( NULL == mb ) return 1;
   28  
   29     // Need option handling here for input filename
   30     if( argc > 1 )
   31     {
   32         // User has input a mesh file
   33         test_file_name = argv[1];
   34     }
   35  
   36     // Load the mesh from vtk file
   37     ErrorCode rval = mb->load_mesh( test_file_name.c_str() );MB_CHK_ERR( rval );
   38  
   39     // Get verts entities, by type
   40     Range verts;
   41     rval = mb->get_entities_by_type( 0, MBVERTEX, verts );MB_CHK_ERR( rval );
   42  
   43     // Get edge entities, by type
   44     Range edges;
   45     rval = mb->get_entities_by_type( 0, MBEDGE, edges );MB_CHK_ERR( rval );
   46  
   47     // Get faces, by dimension, so we stay generic to entity type
   48     Range faces;
   49     rval = mb->get_entities_by_dimension( 0, 2, faces );MB_CHK_ERR( rval );
   50  
   51     // Get regions, by dimension, so we stay generic to entity type
   52     Range elems;
   53     rval = mb->get_entities_by_dimension( 0, 3, elems );MB_CHK_ERR( rval );
   54  
   55     // Output the number of entities
   56     cout << "Number of vertices is " << verts.size() << endl;
   57     cout << "Number of edges is " << edges.size() << endl;
   58     cout << "Number of faces is " << faces.size() << endl;
   59     cout << "Number of elements is " << elems.size() << endl;
   60  
   61     delete mb;
   62  
   63     return 0;
   64 }