= MPI_Comm_size =
Determines the size of the group associated with a communictor
= Synopsis =
{{{
  #include "mpi.h"
  int MPI_Comm_size ( MPI_Comm comm, int *size )
}}}
= Input Parameter =
{{{
  comm  communicator (handle) 
}}}
= Output Parameter =
{{{
  size  number of processes in the group of comm (integer) 
}}}
= Notes =
MPI_COMM_NULL is not considered a valid argument to this function.
= Example =
[wiki:mpich/point_to_point/demo1]