MPI_Group_excl(3)

NAME
MPI_Group_excl - Create an group from the ranks not listed

SYNOPSIS
#include <mpi.h>
int MPI_Group_excl(MPI_Group group, int n, int *ranks, MPI_Group *out);

#include <pmpi.h>
int PGroup_excl(MPI_Group group, int n, int *ranks, MPI_Group *out);

#include <mpi.h>
MPI::Group MPI::Group::Excl(int n, const int *ranks) const;

INCLUDE 'mpif.h'
MPI_GROUP_EXCL(group, n, ranks, out, ierr)
INTEGER group, n, ranks(*), out, ierr

INPUT PARAMETERS
group
    - group (handle)
n   - number of ranks in array (integer)
ranks
    - array of ranks not in new group (integer array)

OUTPUT PARAMETER
out - the new group (handle).

DESCRIPTION
The MPI_Group_excl() function is used to create a new group from the ranks of an original group. An array of size n ranks is used to determine which ranks are in the new group. Any in that array are not included. If the resulting group is empty, then MPI_GROUP_EMPTY is returned. Otherwise the newly constructed group is returned in out. This new group should eventually be freed with the MPI_Group_free() function. The C++ version of this function passes the new group as the return value. Note that the initial group must be valid (not MPI_GROUP_NULL). PMPI_Group_excl() is the profiling version of this function.

ERRORS
All MPI routines except for MPI_Wtime and MPI_Wtick return an error code. The the current MPI error handler is invoked if the return value is not MPI_SUCCESS. The default error handler aborts, but this may be changed with by using the MPI_Errhandler_set() function. The predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned instead. Note that MPI does not guarentee that an MPI program can continue past an error. In this implementation, all errors except MPI_ERR_INTERN or MPI_ERR_OTHER should always be recoverable. In C, the error code is passed as the return value. In FORTRAN, all functions have an parameter ierr which returns the error code. MPI C++ functions do not directly return an error code. However, C++ users may want to use the MPI::ERRORS_THROW_EXCEPTIONS handler. This will throw an MPI::Exception with the corresponding error code. To prevent exceptions from being raised from within C and Fortran code, they will see all error return values as MPI_ERR_PENDING when this handler is chosen. In this implementation, call MPI::throw_exception() to throw the correct exception if this occurs.
MPI_SUCCESS
    - No error;
MPI_ERR_PENDING
    - Pending exception;
MPI_ERR_GROUP
    - Invalid group;
MPI_ERR_ARG
    - Invalid argument;
MPI_ERR_RANK
    - Invalid rank within the array;
MPI_ERR_INTERN
    - Out of Memory, cannot create a new group.

SEE ALSO
MPI_Group_free(3), MPI_Group_difference(3), MPI_Group_incl(3), MPI_Group_intersection(3), MPI_Group_range_excl(3), MPI_Group_range_incl(3), MPI_Group_union(3)