Mesh Oriented datABase  (version 5.5.1)
An array-based unstructured mesh library
VisTags.cpp

tool for visualizing multi level tags
To run: VisTags <inp_file> <outfile> -O <read_opts> -t <tags> -l <levels> -d <dim>

In this example, it is shown how to create some simple tags for those tags that come from climate data, multiple levels. you can read directly nc data, or *.h5m file that will have the tag with multi levels output will be a vtk file with dense tags of form tag_name_<level> the tag name might contain a time index too, like T0 or U0 <tag> is a list of tags, separated by commas, no spaces <levels> is a list of levels, separated by commas, no spaces dimension of entities with the tags will be specified with -d (default 2)

an example of use

VisTags gcrm_r3.nc out.vtk -O VARIABLE=u -t u0,u1 -l 0,1,2 -d 2 (we knew that it had variable u in the file, that it had 256 levels, that there are 2 time steps, etc)

or VisTags gcrm_r3.nc out.vtk -t u0 -l 0,1,2 -d 2 (it will read all variables, but we need to know that u0 will be created as a tag)

the out.vtk file will contain u0_0, u0_1, as simple dense double tags

/** @example VisTags.cpp \n
* \brief tool for visualizing multi level tags \n
* <b>To run</b>: VisTags <inp_file> <outfile> -O <read_opts> -t <tags> -l <levels> -d <dim> \n
*
* In this example, it is shown how to create some simple tags for those tags that come from
* climate data, multiple levels.
* you can read directly nc data, or *.h5m file that will have the tag with multi levels
* output will be a vtk file with dense tags of form tag_name_<level>
* the tag name might contain a time index too, like T0 or U0
* <tag> is a list of tags, separated by commas, no spaces
* <levels> is a list of levels, separated by commas, no spaces
* dimension of entities with the tags will be specified with -d (default 2)
*
* an example of use
*
* VisTags gcrm_r3.nc out.vtk -O VARIABLE=u -t u0,u1 -l 0,1,2 -d 2
* (we knew that it had variable u in the file, that it had 256 levels, that there are 2 time
* steps, etc)
*
* or
* VisTags gcrm_r3.nc out.vtk -t u0 -l 0,1,2 -d 2
* (it will read all variables, but we need to know that u0 will be created as a tag)
*
* the out.vtk file will contain u0_0, u0_1, as simple dense double tags
*/
#include <iostream>
#include <vector>
#include <sstream>
#include <string>
// Include header for MOAB instance and tag conventions
#include "moab/Core.hpp"
#ifdef MOAB_HAVE_MPI
#endif
using namespace moab;
using namespace std;
int main( int argc, char** argv )
{
#ifdef MOAB_HAVE_NETCDF
#ifdef MOAB_HAVE_MPI
MPI_Init( &argc, &argv );
#endif
ErrorCode rval;
string file_input, file_output;
string read_opts, tags; // Tags to write, separated by commas; it is the name of the tag
if( argc < 2 )
{
file_input = string( MESH_DIR ) + string( "/io/gcrm_r3.nc" );
file_output = "VisTagsOut.vtk";
}
else
{
file_input = argv[1];
file_output = argv[2];
}
read_opts = "";
tags = "";
// Instantiate
Interface* mb = new( std::nothrow ) Core;
if( NULL == mb ) return 1;
int dimension = 2;
// In MOAB, it may have index after reading (T0, T1, etc)
char* levels = NULL; // Levels, separated by commas, no spaces (like 0, 1, 19)
if( argc > 3 )
{
int index = 3;
while( index < argc )
{
if( !strcmp( argv[index], "-O" ) ) // This is for reading options, optional
read_opts = argv[++index];
if( !strcmp( argv[index], "-t" ) ) tags = argv[++index];
if( !strcmp( argv[index], "-l" ) ) levels = argv[++index];
if( !strcmp( argv[index], "-d" ) ) dimension = atoi( argv[++index] );
index++;
}
}
ostringstream opts;
opts << ";;TAGS=" << tags << ";LEVELS=" << levels << "\0";
FileOptions fo( opts.str().c_str() );
vector< string > tagsNames;
vector< int > levelsArray;
fo.get_strs_option( "TAGS", tagsNames );
fo.get_ints_option( "LEVELS", levelsArray );
// Load the input file with the specified options
rval = mb->load_file( file_input.c_str(), 0, read_opts.c_str() );MB_CHK_SET_ERR( rval, "not loading file" );
Range ents;
rval = mb->get_entities_by_dimension( 0, dimension, ents );MB_CHK_SET_ERR( rval, "not getting ents" );
// Now create double tags for entities of dimension
for( size_t i = 0; i < tagsNames.size(); i++ )
{
string tagName = tagsNames[i];
Tag tagh;
rval = mb->tag_get_handle( tagName.c_str(), tagh );
if( MB_SUCCESS != rval )
{
cout << "not getting tag " << tagName.c_str() << "\n";
continue;
}
int len = 0;
rval = mb->tag_get_length( tagh, len );
if( MB_SUCCESS != rval )
{
cout << "not getting tag len " << tagName.c_str() << "\n";
continue;
}
DataType type;
rval = mb->tag_get_data_type( tagh, type );
if( MB_SUCCESS != rval )
{
cout << "not getting tag type " << tagName.c_str() << "\n";
continue;
}
int count;
void* dataptr; // Assume double tags, for simplicity
rval = mb->tag_iterate( tagh, ents.begin(), ents.end(), count, dataptr );
if( MB_SUCCESS != rval || count != (int)ents.size() )
{
cout << "not getting tag iterate right " << tagName.c_str() << "\n";
continue;
}
// Now create a new tag, with a new name, concatenated, and copy data there , for each level
for( size_t j = 0; j < levelsArray.size(); j++ )
{
int level = levelsArray[j];
if( level >= len )
{
cout << "level too big at " << level << "\n";
continue;
}
ostringstream newTagName;
newTagName << tagName << "_" << level;
Tag newTagh;
rval = mb->tag_get_handle( newTagName.str().c_str(), 1, type, newTagh, MB_TAG_DENSE | MB_TAG_CREAT );
if( MB_SUCCESS != rval )
{
cout << "not getting new tag " << newTagName.str() << "\n";
continue;
}
void* newDataPtr;
rval = mb->tag_iterate( newTagh, ents.begin(), ents.end(), count, newDataPtr );
if( MB_SUCCESS != rval || count != (int)ents.size() )
{
cout << "not getting new tag iterate " << newTagName.str() << "\n";
continue;
}
if( MB_TYPE_DOUBLE == type )
{
double* ptrD = (double*)newDataPtr;
double* oldData = (double*)dataptr;
for( int k = 0; k < count; k++, ptrD++ )
*ptrD = oldData[level + count * k];
}
} // for (size_t j = 0; j < levelsArray.size(); j++)
mb->tag_delete( tagh ); // No need for the tag anymore, write it to the new file
} // for (size_t i = 0; i < tagsNames.size(); i++)
rval = mb->write_file( file_output.c_str() );MB_CHK_SET_ERR( rval, "Can't write file " << file_output );
cout << "Successfully wrote file " << file_output << "\n";
delete mb;
#ifdef MOAB_HAVE_MPI
MPI_Finalize();
#endif
#else
std::cout << " configure with netcdf for this example to work\n";
#endif
return 0;
}