Typically, the functions already presented are used to create and use Cartesian topologies. However, some applications may want more control over the process. MPI_CART_MAP returns the Cartesian map recommended by the MPI system, in order to map well the virtual communication graph of the application on the physical machine topology. This call is collective.
MPI_Cart_map(MPI_Comm comm, int ndims, int *dims, int *periods, int *newrank)
MPI_CART_MAP(COMM, NDIMS, DIMS, PERIODS, NEWRANK, IERROR)INTEGER COMM, NDIMS, DIMS(*), NEWRANK, IERROR
MPI_CART_MAP computes an ``optimal'' placement for the calling process on the physical machine.