
Signed-off-by: Fangcong Yin <fyin2@nd.edu> Convert MPI_Graph_create.3in - MPI_Group_intersection.3in to md files Update ompi/mpi/man/man3/MPI_Grequest_complete.md Signed-off-by: Fangcong Yin <fyin2@nd.edu> Co-authored-by: Jeff Squyres <jsquyres@users.noreply.github.com> Update ompi/mpi/man/man3/MPI_Group_excl.md Signed-off-by: Fangcong Yin <fyin2@nd.edu> Co-authored-by: Jeff Squyres <jsquyres@users.noreply.github.com>
2.2 KiB
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
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_GROUP_INTERSECTION(GROUP1, GROUP2, NEWGROUP, IERROR)
INTEGER GROUP1, GROUP2, NEWGROUP, IERROR
Fortran 2008 Syntax
USE mpi_f08
MPI_Group_intersection(group1, group2, newgroup, ierror)
TYPE(MPI_Group), INTENT(IN) :: group1, group2
TYPE(MPI_Group), INTENT(OUT) :: newgroup
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
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:
union
-- All elements of the first group (group1
), followed by all elements of second group (group2
) not in first.intersect
-- all elements of the first group that are also in the second group, ordered as in first group.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.
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.