Introduction So far, the communicator that you are familiar with is MPI COMM WORLD This is a communicator defined by MPI to permit all processes of your program to communicate with each other at run time, either between two processes( point to-point )or among all processes( collective For some applications however, communications among a selected subgroup of processes may be desirable or required In this section, you will learn how to create new communicators for these situationsIntroduction • So far, the communicator that you are familiar with is MPI_COMM_WORLD. • This is a communicator defined by MPI to permit all processes of your program to communicate with each other at run time, either between two processes ( point￾to-point ) or among all processes ( collective ). • For some applications however, communications among a selected subgroup of processes may be desirable or required. • In this section, you will learn how to create new communicators for these situations