MPI_Cart_map(3) MPI MPI_Cart_map(3) NAME MPI_Cart_map - Maps process to Cartesian topology information SYNOPSIS #include "mpi.h" int MPI_Cart_map ( MPI_Comm comm_old, int ndims, int *dims, int *periods, int *newrank) INPUT PARAMETERS comm - input communicator (handle) ndims - number of dimensions of Cartesian structure (integer) dims - integer array of size ndims specifying the number of processes in each coordinate direction periods - logical array of size ndims specifying the periodicity speci- fication in each coordinate direction OUTPUT PARAMETER newrank - reordered rank of the calling process; MPI_UNDEFINED if call- ing process does not belong to grid (integer) NOTES FOR FORTRAN All 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. ERRORS 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 prede- fined 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. MPI_SUCCESS - No error; MPI routine completed successfully. MPI_ERR_COMM - Invalid communicator. A common error is to use a null commu- nicator in a call (not even allowed in MPI_Comm_rank ). MPI_ERR_DIMS - Illegal dimension argument. A dimension argument is null or its length is less than or equal to zero. MPI_ERR_ARG - Invalid argument. Some argument is invalid and is not identi- fied by a specific error class (e.g., MPI_ERR_RANK ). LOCATION cart_map.c 3/28/2002 MPI_Cart_map(3)