17.2.185. MPI_Group_excl

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, const int ranks[],
    MPI_Group *newgroup) Fortran Syntax

! or the older form: INCLUDE 'mpif.h'

    INTEGER GROUP, N, RANKS(*), NEWGROUP, IERROR Fortran 2008 Syntax

USE mpi_f08

MPI_Group_excl(group, n, ranks, newgroup, ierror)
    TYPE(MPI_Group), INTENT(IN) :: group
    INTEGER, INTENT(IN) :: n, ranks(n)
    TYPE(MPI_Group), INTENT(OUT) :: newgroup
    INTEGER, OPTIONAL, INTENT(OUT) :: ierror 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.

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.