2: #include petsc.h 6: /*@C 7: PetscSetCommWorld - Sets a communicator to be PETSc world communicator 8: (default is MPI_COMM_WORLD). Must call BEFORE PetscInitialize(). 10: Collective on MPI_Comm 12: Input Parameter: 13: . comm - the communicator 15: Note: 16: This routine is intended for users who need to initialize PETSc on a 17: subset of processors within a larger job. Thus, most users need not 18: call this routine. 20: Level: advanced 22: Concepts: communicator^setting for PETSc 23: Concepts: MPI communicator^setting for PETSc 24: Concepts: PETSC_COMM_WORLD^setting 26: @*/ 27: PetscErrorCode PetscSetCommWorld(MPI_Comm comm) 28: { 30: if (PetscInitializeCalled) SETERRQ(PETSC_ERR_ARG_WRONGSTATE,"Must call before PetscInitialize()"); 31: PETSC_COMM_WORLD = comm; 32: return(0); 33: }