is a simple wrapper around MPI_Send. Its main purpose is
to allow for some experimentation / tuning of this simple routine.
Successful completion is indicated by the returned error code
MPI_SUCCESS. In the case of messages of length less than or equal to
zero, this function returns immediately.
SBUF (local input) double *
On entry, SBUF specifies the starting address of buffer to be
SCOUNT (local input) int
On entry, SCOUNT specifies the number of double precision
entries in SBUF. SCOUNT must be at least zero.
DEST (local input) int
On entry, DEST specifies the rank of the receiving process in
the communication space defined by COMM.
STAG (local input) int
On entry, STAG specifies the message tag to be used for this
COMM (local input) MPI_Comm
The MPI communicator identifying the communication space.