mpi_comm_group(3openmpi) [osx man page]

MPI_Comm_group(3OpenMPI)												  MPI_Comm_group(3OpenMPI)

NAME

       MPI_Comm_group  - Returns the group associated with a communicator.

SYNTAX

C Syntax
       #include <mpi.h>
       int MPI_Comm_group(MPI_Comm comm, MPI_Group *group)

Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_COMM_GROUP(COMM, GROUP, IERROR)
	    INTEGER   COMM, GROUP, IERROR

C++ Syntax
       #include <mpi.h>
       Group Comm::Get_group() const

INPUT PARAMETER

       comm	 Communicator.

OUTPUT PARAMETERS

       group	 Group in communicator (handle).

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       If the communicator is an intercommunicator (enables communication between two groups of processes), this function returns the local group.
       To return the remote group, use the MPI_Comm_remote_group function.

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++ func-
       tions  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.

Open MPI 1.2							  September 2006					  MPI_Comm_group(3OpenMPI)

MPI_Comm_rank(3OpenMPI) 												   MPI_Comm_rank(3OpenMPI)

NAME

       MPI_Comm_rank - Determines the rank of the calling process in the communicator.

SYNTAX

C Syntax
       #include <mpi.h>
       int MPI_Comm_rank(MPI_Comm comm, int *rank)

Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_COMM_RANK(COMM, RANK, IERROR)
	    INTEGER   COMM, RANK, IERROR

C++ Syntax
       #include <mpi.h>
       int Comm::Get_rank() const

INPUT PARAMETERS

       comm	 Communicator (handle).

OUTPUT PARAMETERS

       rank	 Rank of the calling process in group of comm (integer).

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       This  function gives the rank of the process in the particular communicator's group. It is equivalent to accessing the communicator's group
       with MPI_Comm_group, computing the rank using MPI_Group_rank, and then freeing the temporary group via MPI_Group_free.

       Many programs will be written with the master-slave model, where one process (such as the rank-zero process) will play a supervisory  role,
       and  the  other	processes  will  serve as compute nodes. In this framework, MPI_Comm_size and MPI_Comm_rank are useful for determining the
       roles of the various processes of a communicator.

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++ func-
       tions  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.

SEE ALSO

       MPI_Comm_group
       MPI_Comm_size
       MPI_Comm_compare

Open MPI 1.2							  September 2006					   MPI_Comm_rank(3OpenMPI)