NAME¶

MPI_Cart_get - Retrieves Cartesian topology information associated with a communicator.

SYNTAX¶

C Syntax¶

#include <mpi.h>
int MPI_Cart_get(MPI_Comm comm, int maxdims, int dims[], int periods[],
	int coords[])

Fortran Syntax¶

USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_CART_GET(COMM, MAXDIMS, DIMS, PERIODS, COORDS, IERROR)
	INTEGER	COMM, MAXDIMS, DIMS(*), COORDS(*), IERROR
	LOGICAL	PERIODS(*)

Fortran 2008 Syntax¶

USE mpi_f08
MPI_Cart_get(comm, maxdims, dims, periods, coords, ierror)
	TYPE(MPI_Comm), INTENT(IN) :: comm
	INTEGER, INTENT(IN) :: maxdims
	INTEGER, INTENT(OUT) :: dims(maxdims), coords(maxdims)
	LOGICAL, INTENT(OUT) :: periods(maxdims)
	INTEGER, OPTIONAL, INTENT(OUT) :: ierror

C++ Syntax¶

#include <mpi.h>
void Cartcomm::Get_topo(int maxdims, int dims[],
	bool periods[], int coords[]) const

INPUT PARAMETERS¶

comm

Communicator with Cartesian structure (handle).

maxdims

Length of vectors dims, periods, and coords in the calling program (integer).

OUTPUT PARAMETERS¶

dims

Number of processes for each Cartesian dimension (array of integers).

periods

Periodicity (true/false) for each Cartesian dimension (array of logicals).

coords

Coordinates of calling process in Cartesian structure (array of integers).

IERROR

Fortran only: Error status (integer).

DESCRIPTION¶

The functions MPI_Cartdim_get and MPI_Cart_get return the Cartesian topology information that was associated with a communicator by MPI_Cart_create.

ERRORS¶

Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ functions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism will be used to throw an MPI::Exception object.

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.

SEE ALSO¶

MPI_Cartdim_get
MPI_Cart_create