MPI_GRAPH_GET, MPI_Graph_get

Purpose

Retrieves graph topology information from a communicator.

C synopsis

#include <mpi.h>
MPI_Graph_get(MPI_Comm comm,int maxindex,int maxedges,
      int *index,int *edges);

C++ synopsis

#include mpi.h
void MPI::Graphcomm::Get_topo(int maxindex, int maxedges, int index[],
                              int edges[]) const;

FORTRAN synopsis

include 'mpif.h' or use mpi
MPI_GRAPH_GET(INTEGER COMM,INTEGER MAXINDEX,INTEGER MAXEDGES,
      INTEGER INDEX(*),INTEGER EDGES(*),INTEGER IERROR)

Parameters

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

maxindex
     is an integer specifying the length of index in the calling program
     (IN)

maxedges
     is an integer specifying the length of edges in the calling program
     (IN)

index
     is an array of integers containing node degrees (OUT)

edges
     is an array of integers containing node neighbors (OUT)

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

Description

This subroutine retrieves the index and edges graph topology information
associated with a communicator.

Errors

MPI not initialized

MPI already finalized

Invalid communicator

No topology

Invalid topology type
     topology type must be graph

Invalid array size
     maxindex < 0 or maxedges < 0

Related information

     MPI_GRAPH_CREATE