MPI_Group_excl(3)							MPI							 MPI_Group_excl(3)

NAME

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

SYNOPSIS

       int MPI_Group_excl(MPI_Group group, int n, int *ranks, MPI_Group *newgroup)

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 PARAMETER

       newgroup
	      - new group derived from above, preserving the order defined by group (handle)

NOTE

       The  MPI  standard  requires  that each of the ranks to excluded must be a valid rank in the group and all elements must be distinct or the
       function is erroneous.

THREAD AND INTERRUPT SAFETY

       This routine is thread-safe.  This means that this routine may be safely used by multiple threads without the need  for	any  user-provided
       thread  locks.  However, the routine is not interrupt safe.  Typically, this is due to the use of memory allocation routines such as malloc
       or other non-MPICH runtime routines that are themselves not interrupt-safe.

NOTES FOR FORTRAN

       All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have an additional argument ierr at the end of the argument  list.   ierr
       is  an integer and has the same meaning as the return value of the routine in C.  In Fortran, MPI routines are subroutines, and are invoked
       with the call statement.

       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in Fortran.

ERRORS

       All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error value; C routines as the value of the function and Fortran  routines	in
       the  last  argument.  Before the value is returned, the current MPI error handler is called.  By default, this error handler aborts the MPI
       job.  The error handler may  be	changed  with  MPI_Comm_set_errhandler	(for  communicators),  MPI_File_set_errhandler	(for  files),  and
       MPI_Win_set_errhandler  (for  RMA  windows).   The  MPI-1 routine MPI_Errhandler_set may be used but its use is deprecated.  The predefined
       error handler MPI_ERRORS_RETURN may be used to cause error values to be returned.  Note that MPI does not guarentee that an MPI program can
       continue past an error; however, MPI implementations will attempt to continue whenever possible.

       MPI_SUCCESS
	      - No error; MPI routine completed successfully.
       MPI_ERR_GROUP
	      - Null or invalid group passed to function.
       MPI_ERR_INTERN
	      - This error is returned when some part of the MPICH implementation is unable to acquire memory.
       MPI_ERR_ARG
	      - Invalid argument.  Some argument is invalid and is not identified by a specific error class (e.g., MPI_ERR_RANK ).
       MPI_ERR_RANK
	      -  Invalid  source or destination rank.  Ranks must be between zero and the size of the communicator minus one; ranks in a receive (
	      MPI_Recv , MPI_Irecv , MPI_Sendrecv , etc.) may also be MPI_ANY_SOURCE .

SEE ALSO

       MPI_Group_free

LOCATION

       group_excl.c

								     11/6/2010							 MPI_Group_excl(3)