NAME

       MPI_Graph_neighbors_count -  Returns the number of neighbors of a node associated with a graph topology

SYNOPSIS

       int MPI_Graph_neighbors_count(MPI_Comm comm, int rank, int *nneighbors)

INPUT PARAMETERS

       comm   - communicator with graph topology (handle)
       rank   - rank of process in group of comm (integer)

OUTPUT PARAMETERS

       nneighbors
              - number of neighbors of specified process (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 ).
       MPI_ERR_RANK
              - Invalid source or destination rank.  Ranks must be between zero and the size of the communicator
              minus  one;  ranks  in  a  receive  (  MPI_Recv  ,  MPI_Irecv  ,  MPI_Sendrecv , etc.) may also be
              MPI_ANY_SOURCE .

                                                   11/12/2016                       MPI_Graph_neighbors_count(3)