MPI_Cart_rank

Determines process rank in communicator given Cartesian location

Synopsis

#include "mpi.h"
int MPI_Cart_rank ( 
        MPI_Comm comm, 
        int *coords, 
        int *rank )

Input Parameters

	comm	communicator with cartesian structure (handle)
	coords	integer array (of size ndims) specifying the cartesian coordinates of a process

Output Parameter

rank

rank of specified process (integer)

Notes

Out-of-range coordinates are erroneous for non-periodic dimensions. Versions of MPICH before 1.2.2 returned MPI_PROC_NULL for the rank in this case.

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 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.

MPI_SUCCESS

No error; MPI routine completed successfully.

MPI_ERR_TOPOLOGY

Invalid topology. Either there is no topology associated with this communicator, or it is not the correct type (e.g., MPI_CART when expecting MPI_GRAPH).

MPI_ERR_RANK

Invalid source or destination rank. Ranks must be between zero and the size of the communicator minus one; ranks in a receive (MPI_Recv, MPI_Irecv, MPI_Sendrecv, etc.) may also be MPI_ANY_SOURCE.

MPI_ERR_ARG

Invalid argument. Some argument is invalid and is not identified by a specific error class (e.g., MPI_ERR_RANK).

Location:cart_rank.c