#include <mpi.h>
void Graphcomm::Get dims(int nnodes[], int nedges[]) const
INPUT PARAMETER
comm
Communicator for group with graph structure (handle).
OUTPUT PARAMETERS
nnodes
Number of nodes in graph (integer).
nedges
Number of edges in graph (integer).
IERROR
Fortran only: Error status (integer).
DESCRIPTION
Functions MPI_Graphdims_get and MPI_Graph_get retrieve the graph-topology information that was associated with a communicator by MPI_Graph_create.
The information provided by MPI_Graphdims_get can be used to dimension the vectors index and edges correctly for a call to MPI_Graph_get.
ERRORS
Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ functions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism will be used to throw an MPI:Exception object.
Before the error value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.