17.2.176. MPI_Graph_map

MPI_Graph_map - Maps process to graph topology information.

17.2.176.1. Syntax

17.2.176.1.1. C Syntax

#include <mpi.h>

int MPI_Graph_map(MPI_Comm comm, int nnodes, const int index[],
    const int edges[], int *newrank)

17.2.176.1.2. Fortran Syntax

USE MPI
! or the older form: INCLUDE 'mpif.h'

MPI_GRAPH_MAP(COMM, NNODES, INDEX, EDGES, NEWRANK, IERROR)
    INTEGER COMM, NNODES, INDEX(*), EDGES(*), NEWRANK, IERROR

17.2.176.1.3. Fortran 2008 Syntax

USE mpi_f08

MPI_Graph_map(comm, nnodes, index, edges, newrank, ierror)
    TYPE(MPI_Comm), INTENT(IN) :: comm
    INTEGER, INTENT(IN) :: nnodes, index(nnodes), edges(*)
    INTEGER, INTENT(OUT) :: newrank
    INTEGER, OPTIONAL, INTENT(OUT) :: ierror

17.2.176.2. Input Parameters

comm : Input communicator (handle).
nnodes : Number of graph nodes (integer).
index : Integer array specifying the graph structure, see MPI_Graph_create.
edges : Integer array specifying the graph structure.

17.2.176.3. Output Parameters

newrank : Reordered rank of the calling process; MPI_UNDEFINED if the calling process does not belong to graph (integer).
IERROR : Fortran only: Error status (integer).

17.2.176.4. Description

MPI_Cart_map and MPI_Graph_map can be used to implement all other topology functions. In general they will not be called by the user directly, unless he or she is creating additional virtual topology capability other than that provided by MPI.

17.2.176.5. Errors

Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument.

Before the error value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.