WriteSLAC.cpp

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/**
 * MOAB, a Mesh-Oriented datABase, is a software component for creating,
 * storing and accessing finite element mesh data.
 *
 * Copyright 2004 Sandia Corporation.  Under the terms of Contract
 * DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government
 * retains certain rights in this software.
 *
 * 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.
 *
 */

#ifdef WIN32
#ifdef _DEBUG
// turn off warnings that say they debugging identifier has been truncated
// this warning comes up when using some STL containers
#pragma warning( disable : 4786 )
#endif
#endif

#include "WriteSLAC.hpp"

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

#include "netcdf.h"
#include "moab/Interface.hpp"
#include "moab/Range.hpp"
#include "moab/CN.hpp"
#include "Internals.hpp"
#include "ExoIIUtil.hpp"
#include "MBTagConventions.hpp"
#include "moab/WriteUtilIface.hpp"

#ifndef MOAB_HAVE_NETCDF
#error Attempt to compile WriteSLAC with NetCDF disabled.
#endif

namespace moab
{

#define INS_ID( stringvar, prefix, id ) sprintf( stringvar, prefix, id )

#define GET_VAR( name, id, dims )                                     \
    {                                                                 \
        ( id )     = -1;                                              \
        int gvfail = nc_inq_varid( ncFile, name, &( id ) );           \
        if( NC_NOERR == gvfail )                                      \
        {                                                             \
            int ndims;                                                \
            gvfail = nc_inq_varndims( ncFile, id, &ndims );           \
            if( NC_NOERR == gvfail )                                  \
            {                                                         \
                ( dims ).resize( ndims );                             \
                gvfail = nc_inq_vardimid( ncFile, id, &( dims )[0] ); \
            }                                                         \
        }                                                             \
    }

WriterIface* WriteSLAC::factory( Interface* iface )
{
    return new WriteSLAC( iface );
}

WriteSLAC::WriteSLAC( Interface* impl ) : mbImpl( impl ), ncFile( 0 )
{
    assert( impl != NULL );

    impl->query_interface( mWriteIface );

    // Initialize in case tag_get_handle fails below
    //! get and cache predefined tag handles
    int negone = -1;
    impl->tag_get_handle( MATERIAL_SET_TAG_NAME, 1, MB_TYPE_INTEGER, mMaterialSetTag, MB_TAG_SPARSE | MB_TAG_CREAT,
                          &negone );

    impl->tag_get_handle( DIRICHLET_SET_TAG_NAME, 1, MB_TYPE_INTEGER, mDirichletSetTag, MB_TAG_SPARSE | MB_TAG_CREAT,
                          &negone );

    impl->tag_get_handle( NEUMANN_SET_TAG_NAME, 1, MB_TYPE_INTEGER, mNeumannSetTag, MB_TAG_SPARSE | MB_TAG_CREAT,
                          &negone );

    mGlobalIdTag = impl->globalId_tag();

    int dum_val = -1;
    impl->tag_get_handle( "__matSetIdTag", 1, MB_TYPE_INTEGER, mMatSetIdTag, MB_TAG_DENSE | MB_TAG_CREAT, &dum_val );

    impl->tag_get_handle( "WriteSLAC element mark", 1, MB_TYPE_BIT, mEntityMark, MB_TAG_CREAT );
}

WriteSLAC::~WriteSLAC()
{
    mbImpl->release_interface( mWriteIface );
    mbImpl->tag_delete( mEntityMark );
}

void WriteSLAC::reset_matset( std::vector< WriteSLAC::MaterialSetData >& matset_info )
{
    std::vector< WriteSLAC::MaterialSetData >::iterator iter;

    for( iter = matset_info.begin(); iter != matset_info.end(); ++iter )
        delete( *iter ).elements;
}

ErrorCode WriteSLAC::write_file( const char* file_name,
                                 const bool overwrite,
                                 const FileOptions&,
                                 const EntityHandle* ent_handles,
                                 const int num_sets,
                                 const std::vector< std::string >& /* qa_list */,
                                 const Tag* /* tag_list */,
                                 int /* num_tags */,
                                 int /* export_dimension */ )
{
    assert( 0 != mMaterialSetTag && 0 != mNeumannSetTag && 0 != mDirichletSetTag );

    // Check the file name
    if( NULL == strstr( file_name, ".ncdf" ) ) return MB_FAILURE;

    std::vector< EntityHandle > matsets, dirsets, neusets, entities;

    fileName = file_name;

    // Separate into material sets, dirichlet sets, neumann sets

    if( num_sets == 0 )
    {
        // Default to all defined sets
        Range this_range;
        mbImpl->get_entities_by_type_and_tag( 0, MBENTITYSET, &mMaterialSetTag, NULL, 1, this_range );
        std::copy( this_range.begin(), this_range.end(), std::back_inserter( matsets ) );
        this_range.clear();
        mbImpl->get_entities_by_type_and_tag( 0, MBENTITYSET, &mDirichletSetTag, NULL, 1, this_range );
        std::copy( this_range.begin(), this_range.end(), std::back_inserter( dirsets ) );
        this_range.clear();
        mbImpl->get_entities_by_type_and_tag( 0, MBENTITYSET, &mNeumannSetTag, NULL, 1, this_range );
        std::copy( this_range.begin(), this_range.end(), std::back_inserter( neusets ) );
    }
    else
    {
        int dummy;
        for( const EntityHandle* iter = ent_handles; iter < ent_handles + num_sets; ++iter )
        {
            if( MB_SUCCESS == mbImpl->tag_get_data( mMaterialSetTag, &( *iter ), 1, &dummy ) )
                matsets.push_back( *iter );
            else if( MB_SUCCESS == mbImpl->tag_get_data( mDirichletSetTag, &( *iter ), 1, &dummy ) )
                dirsets.push_back( *iter );
            else if( MB_SUCCESS == mbImpl->tag_get_data( mNeumannSetTag, &( *iter ), 1, &dummy ) )
                neusets.push_back( *iter );
        }
    }

    // If there is nothing to write just return.
    if( matsets.empty() && dirsets.empty() && neusets.empty() ) return MB_FILE_WRITE_ERROR;

    std::vector< WriteSLAC::MaterialSetData > matset_info;
    std::vector< WriteSLAC::DirichletSetData > dirset_info;
    std::vector< WriteSLAC::NeumannSetData > neuset_info;

    MeshInfo mesh_info;

    matset_info.clear();
    if( gather_mesh_information( mesh_info, matset_info, neuset_info, dirset_info, matsets, neusets, dirsets ) !=
        MB_SUCCESS )
    {
        reset_matset( matset_info );
        return MB_FAILURE;
    }

    // Try to open the file after gather mesh info succeeds
    int fail = nc_create( file_name, overwrite ? NC_CLOBBER : NC_NOCLOBBER, &ncFile );
    if( NC_NOERR != fail )
    {
        reset_matset( matset_info );
        return MB_FAILURE;
    }

    if( initialize_file( mesh_info ) != MB_SUCCESS )
    {
        reset_matset( matset_info );
        return MB_FAILURE;
    }

    if( write_nodes( mesh_info.num_nodes, mesh_info.nodes, mesh_info.num_dim ) != MB_SUCCESS )
    {
        reset_matset( matset_info );
        return MB_FAILURE;
    }

    if( write_matsets( mesh_info, matset_info, neuset_info ) )
    {
        reset_matset( matset_info );
        return MB_FAILURE;
    }

    fail = nc_close( ncFile );
    if( NC_NOERR != fail ) return MB_FAILURE;

    return MB_SUCCESS;
}

ErrorCode WriteSLAC::gather_mesh_information( MeshInfo& mesh_info,
                                              std::vector< WriteSLAC::MaterialSetData >& matset_info,
                                              std::vector< WriteSLAC::NeumannSetData >& neuset_info,
                                              std::vector< WriteSLAC::DirichletSetData >& dirset_info,
                                              std::vector< EntityHandle >& matsets,
                                              std::vector< EntityHandle >& neusets,
                                              std::vector< EntityHandle >& dirsets )
{
    std::vector< EntityHandle >::iterator vector_iter, end_vector_iter;

    mesh_info.num_nodes    = 0;
    mesh_info.num_elements = 0;
    mesh_info.num_matsets  = 0;

    int id = 0;

    vector_iter     = matsets.begin();
    end_vector_iter = matsets.end();

    mesh_info.num_matsets = matsets.size();

    std::vector< EntityHandle > parent_meshsets;

    // Clean out the bits for the element mark
    mbImpl->tag_delete( mEntityMark );
    mbImpl->tag_get_handle( "WriteSLAC element mark", 1, MB_TYPE_BIT, mEntityMark, MB_TAG_CREAT );

    int highest_dimension_of_element_matsets = 0;

    for( vector_iter = matsets.begin(); vector_iter != matsets.end(); ++vector_iter )
    {
        WriteSLAC::MaterialSetData matset_data;
        matset_data.elements = new Range;

        // For the purpose of qa records, get the parents of these matsets
        if( mbImpl->get_parent_meshsets( *vector_iter, parent_meshsets ) != MB_SUCCESS ) return MB_FAILURE;

        // Get all Entity Handles in the mesh set
        Range dummy_range;
        mbImpl->get_entities_by_handle( *vector_iter, dummy_range, true );

        // Wait a minute, we are doing some filtering here that doesn't make sense at this level CJS

        // Find the dimension of the last entity in this range
        Range::iterator entity_iter = dummy_range.end();
        entity_iter                 = dummy_range.end();
        --entity_iter;
        int this_dim = CN::Dimension( TYPE_FROM_HANDLE( *entity_iter ) );
        entity_iter  = dummy_range.begin();
        while( entity_iter != dummy_range.end() && CN::Dimension( TYPE_FROM_HANDLE( *entity_iter ) ) != this_dim )
            ++entity_iter;

        if( entity_iter != dummy_range.end() )
            std::copy( entity_iter, dummy_range.end(), range_inserter( *( matset_data.elements ) ) );

        assert( matset_data.elements->begin() == matset_data.elements->end() ||
                CN::Dimension( TYPE_FROM_HANDLE( *( matset_data.elements->begin() ) ) ) == this_dim );

        // Get the matset's id
        if( mbImpl->tag_get_data( mMaterialSetTag, &( *vector_iter ), 1, &id ) != MB_SUCCESS )
        {
            MB_SET_ERR( MB_FAILURE, "Couldn't get matset id from a tag for an element matset" );
        }

        matset_data.id                = id;
        matset_data.number_attributes = 0;

        // Iterate through all the elements in the meshset
        Range::iterator elem_range_iter, end_elem_range_iter;
        elem_range_iter     = matset_data.elements->begin();
        end_elem_range_iter = matset_data.elements->end();

        // Get the entity type for this matset, verifying that it's the same for all elements
        // THIS ASSUMES HANDLES SORT BY TYPE!!!
        EntityType entity_type = TYPE_FROM_HANDLE( *elem_range_iter );
        --end_elem_range_iter;
        if( entity_type != TYPE_FROM_HANDLE( *( end_elem_range_iter++ ) ) )
        {
            MB_SET_ERR( MB_FAILURE, "Entities in matset " << id << " not of common type" );
        }

        int dimension = -1;
        if( entity_type == MBQUAD || entity_type == MBTRI )
            dimension = 3;  // Output shells by default
        else if( entity_type == MBEDGE )
            dimension = 2;
        else
            dimension = CN::Dimension( entity_type );

        if( dimension > highest_dimension_of_element_matsets ) highest_dimension_of_element_matsets = dimension;

        matset_data.moab_type = mbImpl->type_from_handle( *( matset_data.elements->begin() ) );
        if( MBMAXTYPE == matset_data.moab_type ) return MB_FAILURE;

        std::vector< EntityHandle > tmp_conn;
        mbImpl->get_connectivity( &( *( matset_data.elements->begin() ) ), 1, tmp_conn );
        matset_data.element_type =
            ExoIIUtil::get_element_type_from_num_verts( tmp_conn.size(), entity_type, dimension );

        if( matset_data.element_type == EXOII_MAX_ELEM_TYPE )
        {
            MB_SET_ERR( MB_FAILURE, "Element type in matset " << id << " didn't get set correctly" );
        }

        matset_data.number_nodes_per_element = ExoIIUtil::VerticesPerElement[matset_data.element_type];

        // Number of nodes for this matset
        matset_data.number_elements = matset_data.elements->size();

        // Total number of elements
        mesh_info.num_elements += matset_data.number_elements;

        // Get the nodes for the elements
        mWriteIface->gather_nodes_from_elements( *matset_data.elements, mEntityMark, mesh_info.nodes );

        if( !neusets.empty() )
        {
            // If there are neusets, keep track of which elements are being written out
            for( Range::iterator iter = matset_data.elements->begin(); iter != matset_data.elements->end(); ++iter )
            {
                unsigned char bit = 0x1;
                mbImpl->tag_set_data( mEntityMark, &( *iter ), 1, &bit );
            }
        }

        matset_info.push_back( matset_data );
    }

    // If user hasn't entered dimension, we figure it out
    if( mesh_info.num_dim == 0 )
    {
        // Never want 1 or zero dimensions
        if( highest_dimension_of_element_matsets < 2 )
            mesh_info.num_dim = 3;
        else
            mesh_info.num_dim = highest_dimension_of_element_matsets;
    }

    Range::iterator range_iter, end_range_iter;
    range_iter     = mesh_info.nodes.begin();
    end_range_iter = mesh_info.nodes.end();

    mesh_info.num_nodes = mesh_info.nodes.size();

    //------dirsets--------

    vector_iter     = dirsets.begin();
    end_vector_iter = dirsets.end();

    for( ; vector_iter != end_vector_iter; ++vector_iter )
    {
        WriteSLAC::DirichletSetData dirset_data;
        dirset_data.id           = 0;
        dirset_data.number_nodes = 0;

        // Get the dirset's id
        if( mbImpl->tag_get_data( mDirichletSetTag, &( *vector_iter ), 1, &id ) != MB_SUCCESS )
        {
            MB_SET_ERR( MB_FAILURE, "Couldn't get id tag for dirset " << id );
        }

        dirset_data.id = id;

        std::vector< EntityHandle > node_vector;
        // Get the nodes of the dirset that are in mesh_info.nodes
        if( mbImpl->get_entities_by_handle( *vector_iter, node_vector, true ) != MB_SUCCESS )
        {
            MB_SET_ERR( MB_FAILURE, "Couldn't get nodes in dirset " << id );
        }

        std::vector< EntityHandle >::iterator iter, end_iter;
        iter     = node_vector.begin();
        end_iter = node_vector.end();

        int j                     = 0;
        unsigned char node_marked = 0;
        ErrorCode result;
        for( ; iter != end_iter; ++iter )
        {
            if( TYPE_FROM_HANDLE( *iter ) != MBVERTEX ) continue;
            result = mbImpl->tag_get_data( mEntityMark, &( *iter ), 1, &node_marked );MB_CHK_SET_ERR( result, "Couldn't get mark data" );

            if( 0x1 == node_marked ) dirset_data.nodes.push_back( *iter );
            j++;
        }

        dirset_data.number_nodes = dirset_data.nodes.size();
        dirset_info.push_back( dirset_data );
    }

    //------neusets--------
    vector_iter     = neusets.begin();
    end_vector_iter = neusets.end();

    for( ; vector_iter != end_vector_iter; ++vector_iter )
    {
        WriteSLAC::NeumannSetData neuset_data;

        // Get the neuset's id
        if( mbImpl->tag_get_data( mNeumannSetTag, &( *vector_iter ), 1, &id ) != MB_SUCCESS ) return MB_FAILURE;

        neuset_data.id              = id;
        neuset_data.mesh_set_handle = *vector_iter;

        // Get the sides in two lists, one forward the other reverse; starts with forward sense
        // by convention
        Range forward_elems, reverse_elems;
        if( get_neuset_elems( *vector_iter, 0, forward_elems, reverse_elems ) == MB_FAILURE ) return MB_FAILURE;

        ErrorCode result = get_valid_sides( forward_elems, 1, neuset_data );MB_CHK_SET_ERR( result, "Couldn't get valid sides data" );
        result = get_valid_sides( reverse_elems, -1, neuset_data );MB_CHK_SET_ERR( result, "Couldn't get valid sides data" );

        neuset_data.number_elements = neuset_data.elements.size();
        neuset_info.push_back( neuset_data );
    }

    // Get information about interior/exterior tets/hexes, and mark matset ids
    return gather_interior_exterior( mesh_info, matset_info, neuset_info );
}

ErrorCode WriteSLAC::get_valid_sides( Range& elems, const int sense, WriteSLAC::NeumannSetData& neuset_data )
{
    // This is where we see if underlying element of side set element is included in output

    unsigned char element_marked = 0;
    ErrorCode result;
    for( Range::iterator iter = elems.begin(); iter != elems.end(); ++iter )
    {
        // Should insert here if "side" is a quad/tri on a quad/tri mesh
        result = mbImpl->tag_get_data( mEntityMark, &( *iter ), 1, &element_marked );MB_CHK_SET_ERR( result, "Couldn't get mark data" );

        if( 0x1 == element_marked )
        {
            neuset_data.elements.push_back( *iter );

            // TJT TODO: the sense should really be # edges + 1or2
            neuset_data.side_numbers.push_back( ( sense == 1 ? 1 : 2 ) );
        }
        else
        {  // Then "side" is probably a quad/tri on a hex/tet mesh
            std::vector< EntityHandle > parents;
            int dimension = CN::Dimension( TYPE_FROM_HANDLE( *iter ) );

            // Get the adjacent parent element of "side"
            if( mbImpl->get_adjacencies( &( *iter ), 1, dimension + 1, false, parents ) != MB_SUCCESS )
            {
                MB_SET_ERR( MB_FAILURE, "Couldn't get adjacencies for neuset" );
            }

            if( !parents.empty() )
            {
                // Make sure the adjacent parent element will be output
                for( unsigned int k = 0; k < parents.size(); k++ )
                {
                    result = mbImpl->tag_get_data( mEntityMark, &( parents[k] ), 1, &element_marked );MB_CHK_SET_ERR( result, "Couldn't get mark data" );

                    int side_no, this_sense, this_offset;
                    if( 0x1 == element_marked &&
                        mbImpl->side_number( parents[k], *iter, side_no, this_sense, this_offset ) == MB_SUCCESS &&
                        this_sense == sense )
                    {
                        neuset_data.elements.push_back( parents[k] );
                        neuset_data.side_numbers.push_back( side_no + 1 );
                        break;
                    }
                }
            }
            else
            {
                MB_SET_ERR( MB_FAILURE, "No parent element exists for element in neuset " << neuset_data.id );
            }
        }
    }

    return MB_SUCCESS;
}

ErrorCode WriteSLAC::write_nodes( const int num_nodes, const Range& nodes, const int dimension )
{
    // See if should transform coordinates
    ErrorCode result;
    Tag trans_tag;
    result                = mbImpl->tag_get_handle( MESH_TRANSFORM_TAG_NAME, 16, MB_TYPE_DOUBLE, trans_tag );
    bool transform_needed = true;
    if( result == MB_TAG_NOT_FOUND ) transform_needed = false;

    int num_coords_to_fill = transform_needed ? 3 : dimension;

    std::vector< double* > coord_arrays( 3 );
    coord_arrays[0] = new double[num_nodes];
    coord_arrays[1] = new double[num_nodes];
    coord_arrays[2] = NULL;

    if( num_coords_to_fill == 3 ) coord_arrays[2] = new double[num_nodes];

    result = mWriteIface->get_node_coords( dimension, num_nodes, nodes, mGlobalIdTag, 0, coord_arrays );
    if( result != MB_SUCCESS )
    {
        delete[] coord_arrays[0];
        delete[] coord_arrays[1];
        if( coord_arrays[2] ) delete[] coord_arrays[2];
        return result;
    }

    if( transform_needed )
    {
        double trans_matrix[16];
        const EntityHandle mesh = 0;
        result                  = mbImpl->tag_get_data( trans_tag, &mesh, 1, trans_matrix );MB_CHK_SET_ERR( result, "Couldn't get transform data" );

        for( int i = 0; i < num_nodes; i++ )
        {
            double vec1[3];
            double vec2[3];

            vec2[0] = coord_arrays[0][i];
            vec2[1] = coord_arrays[1][i];
            vec2[2] = coord_arrays[2][i];

            for( int row = 0; row < 3; row++ )
            {
                vec1[row] = 0.0;
                for( int col = 0; col < 3; col++ )
                    vec1[row] += ( trans_matrix[( row * 4 ) + col] * vec2[col] );
            }

            coord_arrays[0][i] = vec1[0];
            coord_arrays[1][i] = vec1[1];
            coord_arrays[2][i] = vec1[2];
        }
    }

    // Write the nodes
    int nc_var = -1;
    std::vector< int > dims;
    GET_VAR( "coords", nc_var, dims );
    if( -1 == nc_var ) return MB_FAILURE;
    size_t start[2] = { 0, 0 }, count[2] = { static_cast< size_t >( num_nodes ), 1 };
    int fail = nc_put_vara_double( ncFile, nc_var, start, count, coord_arrays[0] );
    if( NC_NOERR != fail ) return MB_FAILURE;
    start[1] = 1;
    fail     = nc_put_vara_double( ncFile, nc_var, start, count, coord_arrays[1] );
    if( NC_NOERR != fail ) return MB_FAILURE;
    start[1] = 2;
    fail     = nc_put_vara_double( ncFile, nc_var, start, count, coord_arrays[2] );
    if( NC_NOERR != fail ) return MB_FAILURE;

    delete[] coord_arrays[0];
    delete[] coord_arrays[1];
    if( coord_arrays[2] ) delete[] coord_arrays[2];

    return MB_SUCCESS;
}

ErrorCode WriteSLAC::gather_interior_exterior( MeshInfo& mesh_info,
                                               std::vector< WriteSLAC::MaterialSetData >& matset_data,
                                               std::vector< WriteSLAC::NeumannSetData >& neuset_data )
{
    // Need to assign a tag with the matset id
    Tag matset_id_tag;
    unsigned int i;
    int dum = -1;
    ErrorCode result =
        mbImpl->tag_get_handle( "__matset_id", 4, MB_TYPE_INTEGER, matset_id_tag, MB_TAG_DENSE | MB_TAG_CREAT, &dum );
    if( MB_SUCCESS != result ) return result;

    Range::iterator rit;
    mesh_info.num_int_hexes = mesh_info.num_int_tets = 0;

    for( i = 0; i < matset_data.size(); i++ )
    {
        WriteSLAC::MaterialSetData matset = matset_data[i];
        if( matset.moab_type == MBHEX )
            mesh_info.num_int_hexes += matset.elements->size();
        else if( matset.moab_type == MBTET )
            mesh_info.num_int_tets += matset.elements->size();
        else
        {
            std::cout << "WriteSLAC doesn't support elements of type " << CN::EntityTypeName( matset.moab_type )
                      << std::endl;
            continue;
        }

        for( rit = matset.elements->begin(); rit != matset.elements->end(); ++rit )
        {
            result = mbImpl->tag_set_data( mMatSetIdTag, &( *rit ), 1, &( matset.id ) );
            if( MB_SUCCESS != result ) return result;
        }
    }

    // Now go through the neumann sets, pulling out the hexes with faces on the
    // boundary
    std::vector< EntityHandle >::iterator vit;
    for( i = 0; i < neuset_data.size(); i++ )
    {
        WriteSLAC::NeumannSetData neuset = neuset_data[i];
        for( vit = neuset.elements.begin(); vit != neuset.elements.end(); ++vit )
        {
            if( TYPE_FROM_HANDLE( *vit ) == MBHEX )
                mesh_info.bdy_hexes.insert( *vit );
            else if( TYPE_FROM_HANDLE( *vit ) == MBTET )
                mesh_info.bdy_tets.insert( *vit );
        }
    }

    // Now we have the number of bdy hexes and tets, we know how many interior ones
    // there are too
    mesh_info.num_int_hexes -= mesh_info.bdy_hexes.size();
    mesh_info.num_int_tets -= mesh_info.bdy_tets.size();

    return MB_SUCCESS;
}

ErrorCode WriteSLAC::write_matsets( MeshInfo& mesh_info,
                                    std::vector< WriteSLAC::MaterialSetData >& matset_data,
                                    std::vector< WriteSLAC::NeumannSetData >& neuset_data )
{
    unsigned int i;
    std::vector< int > connect;
    const EntityHandle* connecth;
    int num_connecth;
    ErrorCode result;

    // First write the interior hexes
    int hex_conn = -1;
    std::vector< int > dims;
    if( mesh_info.bdy_hexes.size() != 0 || mesh_info.num_int_hexes != 0 )
    {
        GET_VAR( "hexahedron_interior", hex_conn, dims );
        if( -1 == hex_conn ) return MB_FAILURE;
    }
    connect.reserve( 13 );
    Range::iterator rit;

    int elem_num = 0;
    WriteSLAC::MaterialSetData matset;
    size_t start[2] = { 0, 0 }, count[2] = { 1, 1 };
    int fail;
    for( i = 0; i < matset_data.size(); i++ )
    {
        matset = matset_data[i];
        if( matset.moab_type != MBHEX ) continue;

        int id     = matset.id;
        connect[0] = id;

        for( rit = matset.elements->begin(); rit != matset.elements->end(); ++rit )
        {
            // Skip if it's on the bdy
            if( mesh_info.bdy_hexes.find( *rit ) != mesh_info.bdy_hexes.end() ) continue;

            // Get the connectivity of this element
            result = mbImpl->get_connectivity( *rit, connecth, num_connecth );
            if( MB_SUCCESS != result ) return result;

            // Get the vertex ids
            result = mbImpl->tag_get_data( mGlobalIdTag, connecth, num_connecth, &connect[1] );
            if( MB_SUCCESS != result ) return result;

            // Put the variable at the right position
            start[0] = elem_num++;
            count[1] = 9;

            // Write the data
            fail = nc_put_vara_int( ncFile, hex_conn, start, count, &connect[0] );
            if( NC_NOERR != fail ) return MB_FAILURE;
        }
    }

    int tet_conn = -1;
    if( mesh_info.bdy_tets.size() != 0 || mesh_info.num_int_tets != 0 )
    {
        GET_VAR( "tetrahedron_interior", tet_conn, dims );
        if( -1 == tet_conn ) return MB_FAILURE;
    }

    // Now the interior tets
    elem_num = 0;
    for( i = 0; i < matset_data.size(); i++ )
    {
        matset = matset_data[i];
        if( matset.moab_type != MBTET ) continue;

        int id     = matset.id;
        connect[0] = id;
        elem_num   = 0;
        for( rit = matset.elements->begin(); rit != matset.elements->end(); ++rit )
        {
            // Skip if it's on the bdy
            if( mesh_info.bdy_tets.find( *rit ) != mesh_info.bdy_tets.end() ) continue;

            // Get the connectivity of this element
            result = mbImpl->get_connectivity( *rit, connecth, num_connecth );
            if( MB_SUCCESS != result ) return result;

            // Get the vertex ids
            result = mbImpl->tag_get_data( mGlobalIdTag, connecth, num_connecth, &connect[1] );
            if( MB_SUCCESS != result ) return result;

            // Put the variable at the right position
            start[0] = elem_num++;
            count[1] = 5;
            fail     = nc_put_vara_int( ncFile, tet_conn, start, count, &connect[0] );
            // Write the data
            if( NC_NOERR != fail ) return MB_FAILURE;
        }
    }

    // Now the exterior hexes
    if( mesh_info.bdy_hexes.size() != 0 )
    {
        hex_conn = -1;
        GET_VAR( "hexahedron_exterior", hex_conn, dims );
        if( -1 == hex_conn ) return MB_FAILURE;

        connect.reserve( 15 );
        elem_num = 0;

        // Write the elements
        for( rit = mesh_info.bdy_hexes.begin(); rit != mesh_info.bdy_hexes.end(); ++rit )
        {
            // Get the material set for this hex
            result = mbImpl->tag_get_data( mMatSetIdTag, &( *rit ), 1, &connect[0] );
            if( MB_SUCCESS != result ) return result;

            // Get the connectivity of this element
            result = mbImpl->get_connectivity( *rit, connecth, num_connecth );
            if( MB_SUCCESS != result ) return result;

            // Get the vertex ids
            result = mbImpl->tag_get_data( mGlobalIdTag, connecth, num_connecth, &connect[1] );
            if( MB_SUCCESS != result ) return result;

            // Preset side numbers
            for( i = 9; i < 15; i++ )
                connect[i] = -1;

            // Now write the side numbers
            for( i = 0; i < neuset_data.size(); i++ )
            {
                std::vector< EntityHandle >::iterator vit =
                    std::find( neuset_data[i].elements.begin(), neuset_data[i].elements.end(), *rit );
                while( vit != neuset_data[i].elements.end() )
                {
                    // Have a side - get the side # and put in connect array
                    int side_no          = neuset_data[i].side_numbers[vit - neuset_data[i].elements.begin()];
                    connect[9 + side_no] = neuset_data[i].id;
                    ++vit;
                    vit = std::find( vit, neuset_data[i].elements.end(), *rit );
                }
            }

            // Put the variable at the right position
            start[0] = elem_num++;
            count[1] = 15;
            fail     = nc_put_vara_int( ncFile, hex_conn, start, count, &connect[0] );
            // Write the data
            if( NC_NOERR != fail ) return MB_FAILURE;
        }
    }

    // Now the exterior tets
    if( mesh_info.bdy_tets.size() != 0 )
    {
        tet_conn = -1;
        GET_VAR( "tetrahedron_exterior", tet_conn, dims );
        if( -1 == tet_conn ) return MB_FAILURE;

        connect.reserve( 9 );
        elem_num = 0;

        // Write the elements
        for( rit = mesh_info.bdy_tets.begin(); rit != mesh_info.bdy_tets.end(); ++rit )
        {
            // Get the material set for this tet
            result = mbImpl->tag_get_data( mMatSetIdTag, &( *rit ), 1, &connect[0] );
            if( MB_SUCCESS != result ) return result;

            // Get the connectivity of this element
            result = mbImpl->get_connectivity( *rit, connecth, num_connecth );
            if( MB_SUCCESS != result ) return result;

            // Get the vertex ids
            result = mbImpl->tag_get_data( mGlobalIdTag, connecth, num_connecth, &connect[1] );
            if( MB_SUCCESS != result ) return result;

            // Preset side numbers
            for( i = 5; i < 9; i++ )
                connect[i] = -1;

            // Now write the side numbers
            for( i = 0; i < neuset_data.size(); i++ )
            {
                std::vector< EntityHandle >::iterator vit =
                    std::find( neuset_data[i].elements.begin(), neuset_data[i].elements.end(), *rit );
                while( vit != neuset_data[i].elements.end() )
                {
                    // Have a side - get the side # and put in connect array
                    int side_no          = neuset_data[i].side_numbers[vit - neuset_data[i].elements.begin()];
                    connect[5 + side_no] = neuset_data[i].id;
                    ++vit;
                    vit = std::find( vit, neuset_data[i].elements.end(), *rit );
                }
            }

            // Put the variable at the right position
            start[0] = elem_num++;
            count[1] = 9;
            fail     = nc_put_vara_int( ncFile, tet_conn, start, count, &connect[0] );
            // Write the data
            if( NC_NOERR != fail ) return MB_FAILURE;
        }
    }

    return MB_SUCCESS;
}

ErrorCode WriteSLAC::initialize_file( MeshInfo& mesh_info )
{
    // Perform the initializations

    int coord_size = -1, ncoords = -1;
    // Initialization to avoid warnings on Linux
    int hexinterior = -1, hexinteriorsize, hexexterior = -1, hexexteriorsize = -1;
    int tetinterior = -1, tetinteriorsize, tetexterior = -1, tetexteriorsize = -1;

    if( nc_def_dim( ncFile, "coord_size", (size_t)mesh_info.num_dim, &coord_size ) != NC_NOERR )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to define number of dimensions" );
    }

    if( nc_def_dim( ncFile, "ncoords", (size_t)mesh_info.num_nodes, &ncoords ) != NC_NOERR )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to define number of nodes" );
    }

    if( 0 != mesh_info.num_int_hexes &&
        nc_def_dim( ncFile, "hexinterior", (size_t)mesh_info.num_int_hexes, &hexinterior ) != NC_NOERR )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to define number of interior hex elements" );
    }

    if( nc_def_dim( ncFile, "hexinteriorsize", (size_t)9, &hexinteriorsize ) != NC_NOERR )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to define interior hex element size" );
    }

    if( 0 != mesh_info.bdy_hexes.size() &&
        nc_def_dim( ncFile, "hexexterior", (size_t)mesh_info.bdy_hexes.size(), &hexexterior ) != NC_NOERR )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to define number of exterior hex elements" );
    }

    if( nc_def_dim( ncFile, "hexexteriorsize", (size_t)15, &hexexteriorsize ) != NC_NOERR )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to define exterior hex element size" );
    }

    if( 0 != mesh_info.num_int_tets &&
        nc_def_dim( ncFile, "tetinterior", (size_t)mesh_info.num_int_tets, &tetinterior ) != NC_NOERR )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to define number of interior tet elements" );
    }

    if( nc_def_dim( ncFile, "tetinteriorsize", (size_t)5, &tetinteriorsize ) != NC_NOERR )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to define interior tet element size" );
    }

    if( 0 != mesh_info.bdy_tets.size() &&
        nc_def_dim( ncFile, "tetexterior", (size_t)mesh_info.bdy_tets.size(), &tetexterior ) != NC_NOERR )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to define number of exterior tet elements" );
    }

    if( nc_def_dim( ncFile, "tetexteriorsize", (size_t)9, &tetexteriorsize ) != NC_NOERR )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to define exterior tet element size" );
    }

    /* ...and some variables */

    int dims[2];
    dims[0] = hexinterior;
    dims[1] = hexinteriorsize;
    int dum_var;
    if( 0 != mesh_info.num_int_hexes &&
        NC_NOERR != nc_def_var( ncFile, "hexahedron_interior", NC_LONG, 2, dims, &dum_var ) )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to create connectivity array for interior hexes" );
    }

    dims[0] = hexexterior;
    dims[1] = hexexteriorsize;
    if( 0 != mesh_info.bdy_hexes.size() &&
        NC_NOERR != nc_def_var( ncFile, "hexahedron_exterior", NC_LONG, 2, dims, &dum_var ) )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to create connectivity array for exterior hexes" );
    }

    dims[0] = tetinterior;
    dims[1] = tetinteriorsize;
    if( 0 != mesh_info.num_int_tets &&
        NC_NOERR != nc_def_var( ncFile, "tetrahedron_exterior", NC_LONG, 2, dims, &dum_var ) )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to create connectivity array for interior tets" );
    }

    dims[0] = tetexterior;
    dims[1] = tetexteriorsize;
    if( 0 != mesh_info.bdy_tets.size() &&
        NC_NOERR != nc_def_var( ncFile, "tetrahedron_exterior", NC_LONG, 2, dims, &dum_var ) )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to create connectivity array for exterior tets" );
    }

    /* Node coordinate arrays: */

    dims[0] = ncoords;
    dims[1] = coord_size;
    if( NC_NOERR != nc_def_var( ncFile, "coords", NC_DOUBLE, 2, dims, &dum_var ) )
    {
        MB_SET_ERR( MB_FAILURE, "WriteSLAC: failed to define node coordinate array" );
    }

    return MB_SUCCESS;
}

ErrorCode WriteSLAC::open_file( const char* filename )
{
    // Not a valid filname
    if( strlen( (const char*)filename ) == 0 )
    {
        MB_SET_ERR( MB_FAILURE, "Output filename not specified" );
    }

    int fail = nc_create( filename, NC_CLOBBER, &ncFile );
    // File couldn't be opened
    if( NC_NOERR != fail )
    {
        MB_SET_ERR( MB_FAILURE, "Cannot open " << filename );
    }

    return MB_SUCCESS;
}

ErrorCode WriteSLAC::get_neuset_elems( EntityHandle neuset,
                                       int current_sense,
                                       Range& forward_elems,
                                       Range& reverse_elems )
{
    Range ss_elems, ss_meshsets;

    // Get the sense tag; don't need to check return, might be an error if the tag
    // hasn't been created yet
    Tag sense_tag = 0;
    mbImpl->tag_get_handle( "SENSE", 1, MB_TYPE_INTEGER, sense_tag );

    // Get the entities in this set
    ErrorCode result = mbImpl->get_entities_by_handle( neuset, ss_elems, true );
    if( MB_FAILURE == result ) return result;

    // Now remove the meshsets into the ss_meshsets; first find the first meshset,
    Range::iterator range_iter = ss_elems.begin();
    while( TYPE_FROM_HANDLE( *range_iter ) != MBENTITYSET && range_iter != ss_elems.end() )
        ++range_iter;

    // Then, if there are some, copy them into ss_meshsets and erase from ss_elems
    if( range_iter != ss_elems.end() )
    {
        std::copy( range_iter, ss_elems.end(), range_inserter( ss_meshsets ) );
        ss_elems.erase( range_iter, ss_elems.end() );
    }

    // OK, for the elements, check the sense of this set and copy into the right range
    // (if the sense is 0, copy into both ranges)

    // Need to step forward on list until we reach the right dimension
    Range::iterator dum_it = ss_elems.end();
    --dum_it;
    int target_dim = CN::Dimension( TYPE_FROM_HANDLE( *dum_it ) );
    dum_it         = ss_elems.begin();
    while( target_dim != CN::Dimension( TYPE_FROM_HANDLE( *dum_it ) ) && dum_it != ss_elems.end() )
        ++dum_it;

    if( current_sense == 1 || current_sense == 0 ) std::copy( dum_it, ss_elems.end(), range_inserter( forward_elems ) );
    if( current_sense == -1 || current_sense == 0 )
        std::copy( dum_it, ss_elems.end(), range_inserter( reverse_elems ) );

    // Now loop over the contained meshsets, getting the sense of those and calling this
    // function recursively
    for( range_iter = ss_meshsets.begin(); range_iter != ss_meshsets.end(); ++range_iter )
    {
        // First get the sense; if it's not there, by convention it's forward
        int this_sense;
        if( 0 == sense_tag || MB_FAILURE == mbImpl->tag_get_data( sense_tag, &( *range_iter ), 1, &this_sense ) )
            this_sense = 1;

        // Now get all the entities on this meshset, with the proper (possibly reversed) sense
        get_neuset_elems( *range_iter, this_sense * current_sense, forward_elems, reverse_elems );
    }

    return result;
}

}  // namespace moab