NAME

       MPI_Graphdims_get -  Retrieves graph topology information associated with a  communicator

SYNOPSIS

       int MPI_Graphdims_get(MPI_Comm comm, int *nnodes, int *nedges)

INPUT PARAMETERS

       comm   - communicator for group with graph structure (handle)

OUTPUT PARAMETERS

       nnodes - number of nodes in graph (integer)
       nedges - number of edges in graph (integer)

THREAD AND INTERRUPT SAFETY

       This  routine is both thread- and interrupt-safe.  This means that this routine may safely
       be used by multiple threads and from within a signal handler.

NOTES FOR FORTRAN

       All MPI routines in Fortran (except for MPI_WTIME  and  MPI_WTICK  )  have  an  additional
       argument  ierr  at  the  end  of  the  argument list.  ierr is an integer and has the same
       meaning as the  return  value  of  the  routine  in  C.   In  Fortran,  MPI  routines  are
       subroutines, and are invoked with the call statement.

       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in Fortran.

ERRORS

       All  MPI  routines  (except MPI_Wtime and MPI_Wtick ) return an error value; C routines as
       the value of the function and Fortran routines in the last argument.  Before the value  is
       returned,  the current MPI error handler is called.  By default, this error handler aborts
       the MPI  job.   The  error  handler  may  be  changed  with  MPI_Comm_set_errhandler  (for
       communicators),  MPI_File_set_errhandler  (for files), and MPI_Win_set_errhandler (for RMA
       windows).  The MPI-1 routine MPI_Errhandler_set may be used but  its  use  is  deprecated.
       The  predefined  error  handler  MPI_ERRORS_RETURN may be used to cause error values to be
       returned.  Note that MPI does not guarentee that an  MPI  program  can  continue  past  an
       error; however, MPI implementations will attempt to continue whenever possible.

       MPI_SUCCESS
              - No error; MPI routine completed successfully.
       MPI_ERR_TOPOLOGY
              - Invalid topology.  Either there is no topology associated with this communicator,
              or it is not the correct type (e.g., MPI_CART when expecting MPI_GRAPH ).
       MPI_ERR_COMM
              - Invalid communicator.  A common error is to use a null  communicator  in  a  call
              (not even allowed in MPI_Comm_rank ).
       MPI_ERR_ARG
              -  Invalid  argument.  Some argument is invalid and is not identified by a specific
              error class (e.g., MPI_ERR_RANK ).

                                            11/12/2016                       MPI_Graphdims_get(3)