MPI_Graph_create(3)

NAME
     MPI_Graph_create - Makes a new communicator and attaches topology
     information

SYNOPSIS
     C:

          #include <mpi.h>

          int MPI_Graph_create ( comm_old, nnodes, index, edges,
          reorder, comm_graph )
          MPI_Comm  comm_old;
          int       nnodes;
          int      *index;
          int      *edges;
          int       reorder;
          MPI_Comm *comm_graph;


     C++:

          #include <mpi.h>

          Graphcomm Intracomm::Create_graph(
          int               nnodes,
          const int         index[],
          const int         edges[],
          bool              reorder) const


     Fortran:

          INCLUDE "mpif.h" (or USE MPI)

          INTEGER comm_old, *Vnnodes, index(*), edges(*),
          comm_graph, ierror
          LOGICAL reorder

          CALL MPI_GRAPH_CREATE(comm_old, *Vnnodes, index(*), edges(*),
          reorder, comm_graph, ierror)


STANDARDS
     This release implements the MPI 1.2 standard, as documented by the MPI
     Forum in the spring 1997 release of MPI:  A Message Passing Interface
     Standard.

DESCRIPTION
     The MPI_Graph_create routine makes a new communicator and attaches
     topology information.  This routine accepts the following parameters:
     comm_old       Specifies the input communicator without topology
                    (handle).

     nnodes         Specifies the number of nodes in the graph (integer).

     index          Specifies an array of integers describing node degrees.

     edges          Specifies an array of integers describing graph edges.

     reorder        Specifies that ranking can be reordered (true) or cannot
                    be ordered (false) (logical).

     comm_graph     Returns the communicator with graph topology added
                    (handle).

     ierror         Specifies the return code value for successful completion,
                    which is in MPI_SUCCESS.  MPI_SUCCESS is defined in the
                    mpif.h file.