17.2.34. MPI_Cart_coords

MPI_Cart_coords - Determines process coords in Cartesian topology given rank in group.

17.2.34.1. Syntax

17.2.34.1.1. C Syntax

#include <mpi.h>

int MPI_Cart_coords(MPI_Comm comm, int rank, int maxdims,
    int coords[])

17.2.34.1.2. Fortran Syntax

USE MPI
! or the older form: INCLUDE 'mpif.h'

MPI_CART_COORDS(COMM, RANK, MAXDIMS, COORDS, IERROR)
    INTEGER COMM, RANK, MAXDIMS, COORDS(*), IERROR

17.2.34.1.3. Fortran 2008 Syntax

USE mpi_f08

MPI_Cart_coords(comm, rank, maxdims, coords, ierror)
    TYPE(MPI_Comm), INTENT(IN) :: comm
    INTEGER, INTENT(IN) :: rank, maxdims
    INTEGER, INTENT(OUT) :: coords(maxdims)
    INTEGER, OPTIONAL, INTENT(OUT) :: ierror

17.2.34.2. Input Parameters

  • comm : Communicator with Cartesian structure (handle).

  • rank : Rank of a process within group of comm (integer).

  • maxdims : Length of vector coords in the calling program (integer). Length of vector coords in the calling program (integer).

17.2.34.3. Output Parameters

  • coords : Integer array (of size ndims,which was defined by MPI_Cart_create call) containing the Cartesian coordinates of specified process (integer).

  • IERROR : Fortran only: Error status (integer).

17.2.34.4. Description

MPI_Cart_coords provides a mapping of ranks to Cartesian coordinates.

17.2.34.5. Errors

Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. Before the error value is returned, the current MPI error handler is called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.