MPI Functions

int MPI_Comm_dup( MPI_Comm old_comm,

MPI_Comm *new_comm);

int MPI_Comm_free( MPI_Comm comm);

int MPI_Comm_compare( MPI_Comm comm1,

MPI_Comm comm2,

int *result);

goups and contexts identical, returns MPI_IDENT

groups identical but contexts different, returns MPI_CONGRUENT

groups contain the same processes but the order if different, returns MPI_SIMILAR

otherwise, returns MPI_UNEQUAL

int MPI_Group_translate_ranks( MPI_Group group1,

int array_size,

int *ranks_in_g1,

MPI_Group group2,

int *ranks_in_g2);

if process i in group 1 with rank array ranks_in_g1[i] is in group 2, return rank in group 2

othersize, return MPI_UNDEFINED