ReadNASTRAN.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.
 *
 */
 
#include "ReadNASTRAN.hpp"
 
#include <iostream>
#include <sstream>
#include <fstream>
#include <vector>
#include <cstdlib>
#include <cassert>
#include <cmath>
 
#include "moab/Interface.hpp"
#include "moab/ReadUtilIface.hpp"
#include "Internals.hpp" // For MB_START_ID
#include "moab/Range.hpp"
#include "moab/FileOptions.hpp"
#include "FileTokenizer.hpp"
#include "MBTagConventions.hpp"
#include "moab/CN.hpp"
 
namespace moab
{
 
ReaderIface* ReadNASTRAN::factory( Interface* iface )
{
 return new ReadNASTRAN( iface );
}
 
// Constructor
ReadNASTRAN::ReadNASTRAN( Interface* impl ) : MBI( impl )
{
 assert( NULL != impl );
 MBI->query_interface( readMeshIface );
 assert( NULL != readMeshIface );
}
 
// Destructor
ReadNASTRAN::~ReadNASTRAN()
{
 if( readMeshIface )
 {
 MBI->release_interface( readMeshIface );
 readMeshIface = 0;
 }
}
 
ErrorCode ReadNASTRAN::read_tag_values( const char* /*file_name*/,
 const char* /*tag_name*/,
 const FileOptions& /*opts*/,
 std::vector< int >& /*tag_values_out*/,
 const SubsetList* /*subset_list*/ )
{
 return MB_NOT_IMPLEMENTED;
}
 
// Load the file as called by the Interface function
ErrorCode ReadNASTRAN::load_file( const char* filename,
 const EntityHandle* /* file_set */,
 const FileOptions& /* opts */,
 const ReaderIface::SubsetList* subset_list,
 const Tag* file_id_tag )
{
 // At this time there is no support for reading a subset of the file
 if( subset_list )
 {
 MB_SET_ERR( MB_UNSUPPORTED_OPERATION, "Reading subset of files not supported for NASTRAN" );
 }
 
 nodeIdMap.clear();
 elemIdMap.clear();
 
 bool debug = false;
 if( debug ) std::cout << "begin ReadNASTRAN::load_file" << std::endl;
 ErrorCode result;
 
 // Count the entities of each type in the file. This is used to allocate the node array.
 int entity_count[MBMAXTYPE];
 for( int i = 0; i < MBMAXTYPE; i++ )
 entity_count[i] = 0;
 
 /* Determine the line_format of the first line. Assume that the entire file
 has the same format. */
 std::string line;
 std::ifstream file( filename );
 if( !getline( file, line ) ) return MB_FILE_DOES_NOT_EXIST;
 line_format format;
 result = determine_line_format( line, format );
 if( MB_SUCCESS != result ) return result;
 
 /* Count the number of each entity in the file. This allows one to allocate
 a sequential array of vertex handles. */
 while( !file.eof() )
 {
 // Cut the line into fields as determined by the line format.
 // Use a vector to allow for an unknown number of tokens (continue lines).
 // Continue lines are not implemented.
 std::vector< std::string > tokens;
 tokens.reserve( 10 ); // assume 10 fields to avoid extra vector resizing
 result = tokenize_line( line, format, tokens );
 if( MB_SUCCESS != result ) return result;
 
 // Process the tokens of the line. The first token describes the entity type.
 EntityType type;
 result = determine_entity_type( ( tokens.empty() ) ? "" : tokens.front(), type );
 if( MB_SUCCESS != result ) return result;
 entity_count[type]++;
 getline( file, line );
 }
 
 if( debug )
 {
 for( int i = 0; i < MBMAXTYPE; i++ )
 {
 std::cout << "entity_count[" << i << "]=" << entity_count[i] << std::endl;
 }
 }
 
 // Keep list of material sets
 std::vector< Range > materials;
 
 // Now that the number of vertices is known, create the vertices.
 EntityHandle start_vert = 0;
 std::vector< double* > coord_arrays( 3 );
 result = readMeshIface->get_node_coords( 3, entity_count[0], MB_START_ID, start_vert, coord_arrays );
 if( MB_SUCCESS != result ) return result;
 if( 0 == start_vert ) return MB_FAILURE; // check for NULL
 int id, vert_index = 0;
 if( debug ) std::cout << "allocated coord arrays" << std::endl;
 
 // Read the file again to create the entities.
 file.clear(); // Clear eof state from object
 file.seekg( 0 ); // Rewind file
 while( !file.eof() )
 {
 getline( file, line );
 
 // Cut the line into fields as determined by the line format.
 // Use a vector to allow for an unknown number of tokens (continue lines).
 // Continue lines are not implemented.
 std::vector< std::string > tokens;
 tokens.reserve( 10 ); // assume 10 fields to avoid extra vector resizing
 result = tokenize_line( line, format, tokens );
 if( MB_SUCCESS != result ) return result;
 
 // Process the tokens of the line. The first token describes the entity type.
 EntityType type;
 result = determine_entity_type( tokens.front(), type );
 if( MB_SUCCESS != result ) return result;
 
 // Create the entity.
 if( MBVERTEX == type )
 {
 double* coords[3] = { coord_arrays[0] + vert_index, coord_arrays[1] + vert_index,
 coord_arrays[2] + vert_index };
 result = read_node( tokens, debug, coords, id );
 if( MB_SUCCESS != result ) return result;
 if( !nodeIdMap.insert( id, start_vert + vert_index, 1 ).second ) return MB_FAILURE; // Duplicate IDs!
 ++vert_index;
 }
 else
 {
 result = read_element( tokens, materials, type, debug );
 if( MB_SUCCESS != result ) return result;
 }
 }
 
 result = create_materials( materials );
 if( MB_SUCCESS != result ) return result;
 
 result = assign_ids( file_id_tag );
 if( MB_SUCCESS != result ) return result;
 
 file.close();
 nodeIdMap.clear();
 elemIdMap.clear();
 return MB_SUCCESS;
}
 
/* Determine the type of NASTRAN line: small field, large field, or free field.
 small field: each line has 10 fields of 8 characters
 large field: 1x8, 4x16, 1x8. Field 1 must have an asterisk following the character string
 free field: each line entry must be separated by a comma
 Implementation tries to avoid more searches than necessary. */
ErrorCode ReadNASTRAN::determine_line_format( const std::string& line, line_format& format )
{
 std::string::size_type found_asterisk = line.find( "*" );
 if( std::string::npos != found_asterisk )
 {
 format = LARGE_FIELD;
 return MB_SUCCESS;
 }
 else
 {
 std::string::size_type found_comma = line.find( "," );
 if( std::string::npos != found_comma )
 {
 format = FREE_FIELD;
 return MB_SUCCESS;
 }
 else
 {
 format = SMALL_FIELD;
 return MB_SUCCESS;
 }
 }
}
 
/* Tokenize the line. Continue-lines have not been implemented. */
ErrorCode ReadNASTRAN::tokenize_line( const std::string& line,
 const line_format format,
 std::vector< std::string >& tokens )
{
 size_t line_size = line.size();
 switch( format )
 {
 case SMALL_FIELD: {
 // Expect 10 fields of 8 characters.
 // The sample file does not have all 10 fields in each line
 const int field_length = 8;
 unsigned int n_tokens = line_size / field_length;
 for( unsigned int i = 0; i < n_tokens; i++ )
 {
 tokens.push_back( line.substr( i * field_length, field_length ) );
 }
 break;
 }
 case LARGE_FIELD:
 return MB_NOT_IMPLEMENTED;
 case FREE_FIELD:
 return MB_NOT_IMPLEMENTED;
 default:
 return MB_FAILURE;
 }
 
 return MB_SUCCESS;
}
 
ErrorCode ReadNASTRAN::determine_entity_type( const std::string& first_token, EntityType& type )
{
 if( 0 == first_token.compare( "GRID " ) )
 type = MBVERTEX;
 else if( 0 == first_token.compare( "CTETRA " ) )
 type = MBTET;
 else if( 0 == first_token.compare( "CPENTA " ) )
 type = MBPRISM;
 else if( 0 == first_token.compare( "CHEXA " ) )
 type = MBHEX;
 else
 return MB_NOT_IMPLEMENTED;
 
 return MB_SUCCESS;
}
 
/* Some help from Jason:
 Nastran floats must contain a decimal point, may contain
 a leading '-' and may contain an exponent. The 'E' is optional
 when specifying an exponent. A '-' or '+' at any location other
 than the first position indicates an exponent. For a positive
 exponent, either a '+' or an 'E' must be specified. For a
 negative exponent, the 'E' is option and the '-' is always specified.
 Examples for the real value 7.0 from mcs2006 quick reference guide:
 7.0 .7E1 0.7+1 .70+1 7.E+0 70.-1
 
 From the test file created in SC/Tetra:
 GRID 1 03.9804546.9052-15.6008-1
 has the coordinates: ( 3.980454, 6.9052e-1, 5.6008e-1 )
 GRID 200005 04.004752-3.985-15.4955-1
 has the coordinates: ( 4.004752, -3.985e-1, 5.4955e-1 ) */
ErrorCode ReadNASTRAN::get_real( const std::string& token, double& real )
{
 std::string significand = token;
 std::string exponent = "0";
 
 // Cut off the first digit because a "-" could be here indicating a negative
 // number. Instead we are looking for a negative exponent.
 std::string back_token = token.substr( 1 );
 
 // A minus that is not the first digit is always a negative exponent
 std::string::size_type found_minus = back_token.find( "-" );
 if( std::string::npos != found_minus )
 {
 // separate the significand from the exponent at the "-"
 exponent = token.substr( found_minus + 1 );
 significand = token.substr( 0, found_minus + 1 );
 
 // If the significand has an "E", remove it
 if( std::string::npos != significand.find( "E" ) )
 // Assume the "E" is at the end of the significand.
 significand = significand.substr( 1, significand.size() - 2 );
 
 // If a minus does not exist past the 1st digit, but an "E" or "+" does, then
 // it is a positive exponent. First look for an "E",
 }
 else
 {
 std::string::size_type found_E = token.find( "E" );
 if( std::string::npos != found_E )
 {
 significand = token.substr( 0, found_E - 1 );
 exponent = token.substr( found_E + 1 );
 // If there is a "+" on the exponent, cut it off
 std::size_t found_plus = exponent.find( "+" );
 if( std::string::npos != found_plus )
 {
 exponent = exponent.substr( found_plus + 1 );
 }
 }
 else
 {
 // If there is a "+" on the exponent, cut it off
 std::size_t found_plus = token.find( "+" );
 if( std::string::npos != found_plus )
 {
 significand = token.substr( 0, found_plus - 1 );
 exponent = token.substr( found_plus + 1 );
 }
 }
 }
 
 // Now assemble the real number
 double signi = atof( significand.c_str() );
 double expon = atof( exponent.c_str() );
 
 if( HUGE_VAL == signi || HUGE_VAL == expon ) return MB_FAILURE;
 
 real = signi * pow( 10, expon );
 
 return MB_SUCCESS;
}
 
/* It has been determined that this line is a vertex. Read the rest of
 the line and create the vertex. */
ErrorCode ReadNASTRAN::read_node( const std::vector< std::string >& tokens,
 const bool debug,
 double* coords[3],
 int& id )
{
 // Read the node's id (unique)
 ErrorCode result;
 id = atoi( tokens[1].c_str() );
 
 // Read the node's coordinate system number
 // "0" or blank refers to the basic coordinate system.
 int coord_system = atoi( tokens[2].c_str() );
 if( 0 != coord_system )
 {
 std::cerr << "ReadNASTRAN: alternative coordinate systems not implemented" << std::endl;
 return MB_NOT_IMPLEMENTED;
 }
 
 // Read the coordinates
 for( unsigned int i = 0; i < 3; i++ )
 {
 result = get_real( tokens[i + 3], *coords[i] );
 if( MB_SUCCESS != result ) return result;
 if( debug ) std::cout << "read_node: coords[" << i << "]=" << coords[i] << std::endl;
 }
 
 return MB_SUCCESS;
}
 
/* The type of element has already been identified. Read the rest of the
 line and create the element. Assume that all of the nodes have already
 been created. */
ErrorCode ReadNASTRAN::read_element( const std::vector< std::string >& tokens,
 std::vector< Range >& materials,
 const EntityType element_type,
 const bool /*debug*/ )
{
 // Read the element's id (unique) and material set
 ErrorCode result;
 int id = atoi( tokens[1].c_str() );
 int material = atoi( tokens[2].c_str() );
 
 // Resize materials list if necessary. This code is somewhat complicated
 // so as to avoid copying of Ranges
 if( material >= (int)materials.size() )
 {
 if( (int)materials.capacity() < material )
 materials.resize( material + 1 );
 else
 {
 std::vector< Range > new_mat( material + 1 );
 for( size_t i = 0; i < materials.size(); ++i )
 new_mat[i].swap( materials[i] );
 materials.swap( new_mat );
 }
 }
 
 // The size of the connectivity array depends on the element type
 int n_conn = CN::VerticesPerEntity( element_type );
 EntityHandle conn_verts[27];
 assert( n_conn <= (int)( sizeof( conn_verts ) / sizeof( EntityHandle ) ) );
 
 // Read the connected node ids from the file
 for( int i = 0; i < n_conn; i++ )
 {
 int n = atoi( tokens[3 + i].c_str() );
 conn_verts[i] = nodeIdMap.find( n );
 if( !conn_verts[i] ) // invalid vertex id
 return MB_FAILURE;
 }
 
 // Create the element and set the global id from the NASTRAN file
 EntityHandle element;
 result = MBI->create_element( element_type, conn_verts, n_conn, element );
 if( MB_SUCCESS != result ) return result;
 elemIdMap.insert( id, element, 1 );
 
 materials[material].insert( element );
 return MB_SUCCESS;
}
 
ErrorCode ReadNASTRAN::create_materials( const std::vector< Range >& materials )
{
 ErrorCode result;
 Tag material_tag;
 int negone = -1;
 result = MBI->tag_get_handle( MATERIAL_SET_TAG_NAME, 1, MB_TYPE_INTEGER, material_tag, MB_TAG_SPARSE | MB_TAG_CREAT,
 &negone );
 if( MB_SUCCESS != result ) return result;
 
 for( size_t i = 0; i < materials.size(); ++i )
 {
 if( materials[i].empty() ) continue;
 
 // Merge with existing or create new? Original code effectively
 // created new by only merging with existing in current file set,
 // so do the same here. - j.kraftcheck
 
 EntityHandle handle;
 result = MBI->create_meshset( MESHSET_SET, handle );
 if( MB_SUCCESS != result ) return result;
 
 result = MBI->add_entities( handle, materials[i] );
 if( MB_SUCCESS != result ) return result;
 
 int id = i;
 result = MBI->tag_set_data( material_tag, &handle, 1, &id );
 if( MB_SUCCESS != result ) return result;
 }
 
 return MB_SUCCESS;
}
 
ErrorCode ReadNASTRAN::assign_ids( const Tag* file_id_tag )
{
 // Create tag
 ErrorCode result;
 Tag id_tag = MBI->globalId_tag();
 
 RangeMap< int, EntityHandle >::iterator i;
 for( int t = 0; t < 2; ++t )
 {
 RangeMap< int, EntityHandle >& fileIdMap = t ? elemIdMap : nodeIdMap;
 for( i = fileIdMap.begin(); i != fileIdMap.end(); ++i )
 {
 Range range( i->value, i->value + i->count - 1 );
 
 result = readMeshIface->assign_ids( id_tag, range, i->begin );
 if( MB_SUCCESS != result ) return result;
 
 if( file_id_tag && *file_id_tag != id_tag )
 {
 result = readMeshIface->assign_ids( *file_id_tag, range, i->begin );
 if( MB_SUCCESS != result ) return result;
 }
 }
 }
 
 return MB_SUCCESS;
}
 
} // namespace moab