NAME

MPI_Group_incl - Produces a group by reordering an existing group and taking only listed members.

SYNTAX

C Syntax

#include <mpi.h>
int MPI_Group_incl(MPI_Group group, int n, const int ranks[],
	MPI_Group *newgroup)

Fortran Syntax

USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_GROUP_INCL(GROUP, N, RANKS, NEWGROUP, IERROR)
	INTEGER	GROUP, N, RANKS(*), NEWGROUP, IERROR

C++ Syntax

#include <mpi.h>
Group Group::Incl(int n, const int ranks[]) const

INPUT PARAMETERS

group: Group (handle).
n: Number of elements in array ranks (and size of newgroup)(integer).
ranks: Ranks of processes in group to appear in newgroup (array of integers).

OUTPUT PARAMETERS

newgroup: New group derived from above, in the order defined by ranks (handle).
IERROR: Fortran only: Error status (integer).

DESCRIPTION

The function MPI_Group_incl creates a group group_out that consists of the n processes in group with ranks rank[0], ..., rank[n-1]; the process with rank i in group_out is the process with rank ranks[i] in group. Each of the n elements of ranks must be a valid rank in group and all elements must be distinct, or else the program is erroneous. If n = 0, then group_out is MPI_GROUP_EMPTY. This function can, for instance, be used to reorder the elements of a group.

NOTE

This implementation does not currently check to ensure that there are no duplicates in the list of ranks.

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++ functions 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.