MPI_GRAPH_MAP, MPI_Graph_map

Purpose

Computes placement of tasks on the physical processor.

C synopsis

#include <mpi.h>
MPI_Graph_map(MPI_Comm comm,int nnodes,int *index,int *edges,int *newrank);

C++ synopsis

#include mpi.h
int MPI::Graphcomm::Map(int nnodes, const int index[],
                        const int edges[]) const;

FORTRAN synopsis

include 'mpif.h' or use mpi
MPI_GRAPH_MAP(INTEGER COMM,INTEGER NNODES,INTEGER INDEX(*),
              INTEGER EDGES(*),INTEGER NEWRANK,INTEGER IERROR)

Parameters

comm
     is the input communicator (handle) (IN)

nnodes
     is the number of graph nodes (integer) (IN)

index
     is an integer array specifying node degrees (IN)

edges
     is an integer array specifying node adjacency (IN)

newrank
     is the reordered rank,or MPI_Undefined if the calling task does not
     belong to the graph (integer) (OUT)

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

Description

MPI_GRAPH_MAP allows MPI to compute an optimal placement for the calling
task on the physical processor by reordering the tasks in comm.

Notes

MPI_CART_MAP returns newrank as the original rank of the calling task if it
belongs to the grid or MPI_UNDEFINED if it does not.

Errors

Invalid communicator

Invalid communicator type
     must be intracommunicator

Invalid nnodes
     nnodes < 0 or nnodes > groupsize

Invalid node degree
     index[i] < 0

Invalid neighbors
     edges[i] < 0 or edges[i] >= nnodes

MPI not initialized

MPI already finalized

Related information

     MPI_CART_MAP