For a collective operation, indicates that this process is the same group as the root but is
not the root (and thus is not receiving any data). These processes should pass this is as
the root for calls to collective communication procedures. Processes
in the group sending to the root should use the root process' local rank. The root process
should pass in Root.
Namespace:
MPIAssembly: MPI (in MPI.dll)
Version: 1.0.0.0 (1.0.0.0)