MPI_GRAPHDIMS_GET, MPI_Graphdims_get

Purpose

Retrieves graph topology information from a communicator.

C synopsis

#include <mpi.h>
MPI_Graphdims_get(MPI_Comm comm,int *nnodes,int *nedges);

C++ synopsis

#include mpi.h
void MPI::Graphcomm::Get_dims(int nnodes[],
                              int nedges[])
                              const;

FORTRAN synopsis

include 'mpif.h' or use mpi
MPI_GRAPHDIMS_GET(INTEGER COMM,INTEGER NNDODES,INTEGER NEDGES,
      INTEGER IERROR)

Parameters

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

nnodes
     is an integer specifying the number of nodes in the graph. The number
     of nodes and the number of tasks in the group are equal. (OUT)

nedges
     is an integer specifying the number of edges in the graph. (OUT)

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

Description

This subroutine retrieves the number of nodes and the number of edges in
the graph topology associated with a communicator.

Errors

MPI not initialized

MPI already finalized

Invalid communicator

No topology

Invalid topology type
     topology type must be graph

Related information

     MPI_GRAPH_CREATE