AddFieldtoPG2.cpp File Reference

Example demonstrating addition of field data from phys grid to PG2 mesh. More...

#include "moab/ProgOptions.hpp"
#include "moab/Core.hpp"
#include <iostream>

Include dependency graph for AddFieldtoPG2.cpp:

Go to the source code of this file.

Functions
int	main (int argc, char *argv[])

Detailed Description

Example demonstrating addition of field data from phys grid to PG2 mesh.

This example shows how to:

• Load PG2 mesh and phys grid solution files
• Extract variable data from phys grid
• Match entities between phys grid and PG2 mesh using global IDs
• Copy variable data to PG2 mesh cells
• Write enhanced PG2 mesh files for visualization

This tool is useful for transferring field data from phys grid solutions to PG2 mesh representations for climate model analysis.

Author

MOAB Development Team

Date

2024

Description: Add field data from phys grid to PG2 mesh for visualization and analysis

Parameters

argc	Number of command line arguments
argv	Command line arguments array

Returns

0 on success, 1 on failure

Definition in file AddFieldtoPG2.cpp.

Function Documentation

main()

int main	(	int	argc,
		char *	argv[]
	)

Definition at line 32 of file AddFieldtoPG2.cpp.

{
 
    ProgOptions opts;
 
    std::string inputfile, outfile( "out.h5m" ), physgridfile, variable_name;
 
    opts.addOpt< std::string >( "input,i", "input mesh filename", &inputfile );
    opts.addOpt< std::string >( "output,o", "output mesh filename", &outfile );
    opts.addOpt< std::string >( "phys,p", "phys grid solution filename", &physgridfile );
    opts.addOpt< std::string >( "var,v", "variable to extract and add to output file", &variable_name );
 
    opts.parseCommandLine( argc, argv );
 
    if( inputfile.empty() )
    {
        opts.printHelp();
        return 0;
    }
    ErrorCode rval;
    Core* mb = new Core();
 
    EntityHandle fset1, fset2;
    MB_CHK_SET_ERR( mb->create_meshset( MESHSET_SET, fset1 ), "can't create mesh set" );
    MB_CHK_SET_ERR( mb->load_file( inputfile.c_str(), &fset1 ), "can't load input file" );
 
    cout << " opened " << inputfile << " with initial h5m data.\n";
 
    MB_CHK_SET_ERR( mb->create_meshset( MESHSET_SET, fset2 ), "can't create mesh set" );
    MB_CHK_SET_ERR( mb->load_file( physgridfile.c_str(), &fset2 ), "can't load phys grid file" );
 
    Tag tagv;
    MB_CHK_SET_ERR( mb->tag_get_handle( variable_name.c_str(), tagv ), "can't get tag handle" );
 
    Tag gitag = mb->globalId_tag();
 
    Range verts;  // from phys grid
    MB_CHK_SET_ERR( mb->get_entities_by_dimension( fset2, 0, verts ), "can't get vertices" );
    std::vector< int > gids;
    gids.resize( verts.size() );
    MB_CHK_SET_ERR( mb->tag_get_data( gitag, verts, &gids[0] ), "can't get gi tag values" );
    std::vector< double > valsTag;
    valsTag.resize( verts.size() );
    MB_CHK_SET_ERR( mb->tag_get_data( tagv, verts, &valsTag[0] ), "can't get tag vals" );
    Range cells;
 
    MB_CHK_SET_ERR( mb->get_entities_by_dimension( fset1, 2, cells ), "can't get cells" );
 
    std::map< int, double > valsByID;
    for( int i = 0; i < (int)gids.size(); i++ )
        valsByID[gids[i]] = valsTag[i];
 
    // set now cells values
    std::vector< int > cellsIds;
    cellsIds.resize( cells.size() );
    MB_CHK_SET_ERR( mb->tag_get_data( gitag, cells, &cellsIds[0] ), "can't get cells ids" );
    for( int i = 0; i < (int)cells.size(); i++ )
    {
        valsTag[i] = valsByID[cellsIds[i]];
    }
    MB_CHK_SET_ERR( mb->tag_set_data( tagv, cells, &valsTag[0] ), "can't set  cells tags" );
 
    MB_CHK_SET_ERR( mb->write_file( outfile.c_str(), 0, 0, &fset1, 1 ), "can't write file" );
 
    return 0;
}

References ProgOptions::addOpt(), moab::Core::create_meshset(), ErrorCode, moab::Core::get_entities_by_dimension(), moab::Core::globalId_tag(), moab::Core::load_file(), mb, MB_CHK_SET_ERR, MESHSET_SET, ProgOptions::parseCommandLine(), ProgOptions::printHelp(), moab::Range::size(), moab::Core::tag_get_data(), moab::Core::tag_get_handle(), moab::Core::tag_set_data(), and moab::Core::write_file().