mpi_cart_map(3openmpi) [osx man page]

MPI_Cart_map(3OpenMPI)													    MPI_Cart_map(3OpenMPI)

NAME

       MPI_Cart_map  -	Maps process to Cartesian topology information.

SYNTAX

C Syntax
       #include <mpi.h>
       int MPI_Cart_map(MPI_Comm comm, int ndims, int *dims,
	    int *periods, int *newrank)

Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_CART_MAP(COMM, NDIMS, DIMS, PERIODS, NEWRANK, IERROR)
	    INTEGER   COMM, NDIMS, DIMS(*), NEWRANK, IERROR
	    LOGICAL   PERIODS(*)

C++ Syntax
       #include <mpi.h>
       int Cartcomm::Map(int ndims, const int dims[],
	    const bool periods[]) const

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 specification in each coordinate direction.

OUTPUT PARAMETERS

       newrank	 Reordered rank of the calling process; MPI_UNDEFINED if calling process does not belong to grid (integer).

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       MPI_Cart_map  and  MPI_Graph_map  can  be  used	to  implement all other topology functions. In general they will not be called by the user
       directly, unless he or she is creating additional virtual topology capability other than that provided by MPI.

       MPI_Cart_map computes an "optimal" placement for the calling process on the physical machine. A possible implementation of this function is
       to always return the rank of the calling process, that is, not to perform any reordering.

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++ func-
       tions 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_Graph_map

Open MPI 1.2							  September 2006					    MPI_Cart_map(3OpenMPI)

MPI_Cart_map(3) 						      LAM/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, 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 specification in each coordinate direction

OUTPUT PARAMETER

       newrank
	      - reordered rank of the calling process; MPI_UNDEFINED if calling 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

       If an error occurs in an MPI function, the current MPI error handler is called to handle it.  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  (in  C and Fortran; this error handler is less useful in with the C++ MPI bindings.  The predefined error handler
       MPI::ERRORS_THROW_EXCEPTIONS should be used in C++ if the error value needs to be recovered).  Note that MPI does not guarantee that an MPI
       program can continue past an error.

       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.  The C++ bindings for MPI do not return error values; instead, error values are communicated by throwing  exceptions	of
       type MPI::Exception (but not by default).  Exceptions are only thrown if the error value is not MPI::SUCCESS
	.

       Note  that  if the MPI::ERRORS_RETURN handler is set in C++, while MPI functions will return upon an error, there will be no way to recover
       what the actual error value was.
       MPI_SUCCESS
	      - No error; MPI routine completed successfully.
       MPI_ERR_COMM
	      - Invalid communicator.  A common error is to use a null communicator 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 identified by a specific error class.  This is typically a NULL pointer	or
	      other such error.

MORE INFORMATION

       For  more  information,	please	see the official MPI Forum web site, which contains the text of both the MPI-1 and MPI-2 standards.  These
       documents contain detailed information about each MPI function (most of which is not duplicated in these man pages).

       http://www.mpi-forum.org/

ACKNOWLEDGEMENTS

       The LAM Team would like the thank the MPICH Team for the handy program to generate man pages ("doctext" from ftp://ftp.mcs.anl.gov/pub/sow-
       ing/sowing.tar.gz ), the initial formatting, and some initial text for most of the MPI-1 man pages.

LOCATION

       cartmap.c

LAM
/MPI 6.5.8							    11/10/2002							   MPI_Cart_map(3)