mpi_group_difference(3openmpi) [osx man page]

MPI_Group_difference(3OpenMPI)											    MPI_Group_difference(3OpenMPI)

NAME

       MPI_Group_difference  - Makes a group from the difference of two groups.

SYNTAX

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

Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_GROUP_DIFFERENCE(GROUP1, GROUP2, NEWGROUP, IERROR)
	    INTEGER   GROUP1, GROUP2, NEWGROUP, IERROR

C++ Syntax
       #include <mpi.h>
       static Group Group::Difference(const Group& group1, const Group& group2)

INPUT PARAMETERS

       group1	 First group (handle).

       group2	 Second group (handle).

OUTPUT PARAMETERS

       newgroup  Difference 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) 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.

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-
       tions  do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism
       will be used to throw an MPI:Exception object.

       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.

SEE ALSO

       MPI_Group_free

Open MPI 1.2							  September 2006				    MPI_Group_difference(3OpenMPI)

MPI_Group_excl(3OpenMPI)												  MPI_Group_excl(3OpenMPI)

NAME

       MPI_Group_excl - Produces a group by reordering an existing group and taking only unlisted members.

SYNTAX

C Syntax
       #include <mpi.h>
       int MPI_Group_excl(MPI_Group group, int n, int *ranks,
	    MPI_Group *newgroup)

Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_GROUP_EXCL(GROUP, N, RANKS, NEWGROUP, IERROR)
	    INTEGER   GROUP, N, RANKS(*), NEWGROUP, IERROR

C++ Syntax
       #include <mpi.h>
       Group Group::Excl(int n, const int ranks[]) const

INPUT PARAMETERS

       group	 Group (handle).

       n	 Number of elements in array ranks (integer).

       ranks	 Array of integer ranks in group not to appear in newgroup.

OUTPUT PARAMETERS

       newgroup  New group derived from above, preserving the order defined by group (handle).

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       The  function  MPI_Group_excl  creates  a  group  of  processes newgroup that is obtained by deleting from group those processes with ranks
       ranks[0], ... ranks[n-1]. The ordering of processes in newgroup is identical to the ordering in group. Each of the n elements of ranks must
       be  a  valid  rank  in  group  and all elements must be distinct; otherwise, the call is erroneous. If n = 0, then newgroup is identical to
       group.

NOTE

       Currently, each of the ranks to exclude must be a valid rank in the group and all elements must be distinct or the function  is	erroneous.
       This restriction is per the draft.

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-
       tions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception  mechanism
       will be used to throw an MPI:Exception object.

       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.

SEE ALSO

       MPI_Group_range_excl
       MPI_Group_free

Open MPI 1.2							  September 2006					  MPI_Group_excl(3OpenMPI)