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MPI_Group_intersection(3) man page (version 1.3.4)

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NAME

       MPI_Group_intersection   -  Produces a group at the intersection of two
       existing groups.

SYNTAX


C Syntax

       #include <mpi.h>
       int MPI_Group_intersection(MPI_Group group1, MPI_Group group2,
            MPI_Group *newgroup)

Fortran Syntax

       INCLUDE 'mpif.h'
       MPI_GROUP_INTERSECTION(GROUP1, GROUP2, NEWGROUP, IERROR)
            INTEGER   GROUP1, GROUP2, NEWGROUP, IERROR

C++ Syntax

       #include <mpi.h>
       static Group Group::Intersect(const Group& group1, const Group& group2)

INPUT PARAMETERS

       group1    First group (handle).

       group2    Second group (handle).

OUTPUT PARAMETERS

       newgroup  Intersection group (handle).

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       The set-like operations are defined as follows:

         o    union -- All elements of the first group (group1),  followed  by
              all elements of second group (group2) not in first.

         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.

ERRORS

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

SEE ALSO

       MPI_Group_free

1.3.4                            Nov 11, 2009        MPI_Group_intersection(3)

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