MPI_Cart_sub(3)

NAME
     MPI_Cart_sub - Partitions a communicator into subgroups, which form
     lower-dimensional Cartesian subgrids

SYNOPSIS
     C:

          #include <mpi.h>

          int MPI_Cart_sub ( comm, remain_dims, comm_new )
          MPI_Comm  comm;
          int      *remain_dims;
          MPI_Comm *comm_new;


     C++:

          #include <mpi.h>

          Cartcomm Cartcomm::Sub(
          const bool        remain_dims[]) const


     Fortran:

          INCLUDE "mpif.h" (or USE MPI)

          INTEGER comm, newcomm, ierror
          LOGICAL remain_dims(*)

          CALL MPI_CART_SUB(comm, remain_dims(*), newcomm,
          ierror)


STANDARDS
     This release implements the MPI 1.2 standard, as documented by the MPI
     Forum in the spring 1997 release of MPI:  A Message Passing Interface
     Standard.

DESCRIPTION
     The MPI_Cart_sub routine partitions a communicator into subgroups, which
     form lower-dimensional Cartesian subgrids.  This routine accepts the
     following parameters:

     comm           Specifies a communicator with Cartesian structure (handle)

     remain_dims    Specifies whether the ith dimension (indicated by the ith
                    entry of remain_dims) is kept in the subgrid (true) or is
                    dropped (false) (logical vector)
     comm_new       Returns a communicator that contains the subgrid that
                    includes the calling process (handle)

     ierror         Specifies the return code value for successful completion,
                    which is in MPI_SUCCESS.  MPI_SUCCESS is defined in the
                    mpif.h file.