MPI_Comm_createCreates a new communicator
#include "mpi.h" int MPI_Comm_create ( comm, group, comm_out ) MPI_Comm comm; MPI_Group group; MPI_Comm *comm_out;
|group||group, which is a subset of the group of comm (handle)
- new communicator (handle)
Notes for FortranAll MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK) have an additional argument ierr at the end of the argument list. ierr is an integer and has the same meaning as the return value of the routine in C. In Fortran, MPI routines are subroutines, and are invoked with the call statement.
All MPI objects (e.g., MPI_Datatype, MPI_Comm) are of type INTEGER in Fortran.
All MPI routines (except MPI_Wtime and MPI_Wtick) return an error value; C routines as the value of the function and Fortran routines in the last argument. Before the value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job. The error handler may be changed with MPI_Errhandler_set; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarentee that an MPI program can continue past an error.
- No error; MPI routine completed successfully.
- Invalid communicator. A common error is to use a null communicator in a call (not even allowed in MPI_Comm_rank).
- Null group passed to function.
- This error is returned when some part of the MPICH implementation is unable to acquire memory.