MPI_Cart_sub(MPI_Comm comm, int *remain_dims, MPI_Comm *newcomm)
MPI_CART_SUB(COMM, REMAIN_DIMS, NEWCOMM, IERROR)INTEGER COMM, NEWCOMM, IERROR
LOGICAL REMAIN_DIMS(*)
If a Cartesian topology has been created with MPI_CART_CREATE, the function MPI_CART_SUB can be used to partition the communicator group into subgroups that form lower-dimensional Cartesian subgrids, and to build for each subgroup a communicator with the associated subgrid Cartesian topology. This call is collective.