Routines for constructing groups

Constructing Groups

• Set-wise operations on pairs of groups: union, intersection, and difference.
• List ranks to be included in new group:

  mpi_group_incl (group, n, ranks, newgroup, ierr)

  ranks(i) in group has rank i in newgroup.

  List ranks to be excluded from new group:

  mpi_group_excl (group, n, ranks, newgroup, ierr)

  Can also form new groups by specifying ranges of ranks to be included in or excluded from new group.

  mpi_group_range_incl (group, n, ranges, 
                        newgroup, ierr)

  ranges is array of n triplets giving (first, last, stride) of each range included.

  mpi_group_range_excl (group, n, ranges, 
                        newgroup, ierr)