Copyright 2010 Cisco Systems, Inc. All rights reserved.
Copyright 2006-2008 Sun Microsystems, Inc.
Copyright (c) 1996 Thinking Machines Corporation
$COPYRIGHT$
#include <mpi.h> int MPI_Group_difference(MPI_Group group1, MPI_Group group2, MPI_Group *newgroup)
USE MPI ! or the older form: INCLUDE 'mpif.h' MPI_GROUP_DIFFERENCE(GROUP1, GROUP2, NEWGROUP, IERROR) INTEGER GROUP1, GROUP2, NEWGROUP, IERROR
USE mpi_f08 MPI_Group_difference(group1, group2, newgroup, ierror) TYPE(MPI_Group), INTENT(IN) :: group1, group2 TYPE(MPI_Group), INTENT(OUT) :: newgroup INTEGER, OPTIONAL, INTENT(OUT) :: ierror
#include <mpi.h> static Group Group::Difference(const Group& group1, const Group& group2)
1i group1 First group (handle).
1i group2 Second group (handle).
1i newgroup Difference group (handle).
1i IERROR Fortran only: Error status (integer).
o union -- All elements of the first group (group1), followed by all elements of second group (group2) that are not in the first group
o intersect -- all elements of the first group that are also in the second group, ordered as in first group
o difference -- all elements of the first group that are not in the second group, ordered as in the first group
Note that for these operations the order of processes in the output group is determined primarily by order in the first group (if possible) and then, if necessary, by order in the second group. Neither union nor intersection are commutative, but both are associative. The new group can be empty, that is, equal to MPI_GROUP_EMPTY.