MPI_GRAPH_NEIGHBORS_COUNT, MPI_Graph_neighbors_count

Purpose

Returns the number of neighbors of the given task.

C synopsis

#include <mpi.h>
MPI_Graph_neighbors_count(MPI_Comm comm,int rank,
int *neighbors);

C++ synopsis

#include mpi.h
int MPI::Graphcomm::Get_neighbors_count(int rank) const;

FORTRAN synopsis

include 'mpif.h' or use mpi
MPI_GRAPH_NEIGHBORS_COUNT(INTEGER COMM,INTEGER RANK,
INTEGER NEIGHBORS(*),INTEGER IERROR)

Parameters

comm
     is a communicator with graph topology (handle) (IN)

rank
     is the rank of a task within comm (integer) (IN)

neighbors
     is the number of neighbors of the specified task (integer) (OUT)

IERROR
     is the FORTRAN return code. It is always the last argument.

Description

This subroutine returns the number of neighbors of the given task.

Errors

Invalid rank
     rank < 0 or rank > = groupsize

MPI not initialized

MPI already finalized

Invalid communicator

No graph topology associated with communicator

Invalid topology type

Related information

     MPI_GRAPH_CREATE