MPICartmap(3OpenMPI) MPICartmap(3OpenMPI)

NAME
       MMPPIICCaarrttmmaapp  -  Maps process to Cartesian topology information.


SSYYNNTTAAXX
CC SSyynnttaaxx
       #include 
       int MPICartmap(MPIComm comm, int ndims, int *dims,
            int *periods, int *newrank)


FFoorrttrraann SSyynnttaaxx
       INCLUDE 'mpif.h'
       MPICARTMAP(COMM, NDIMS, DIMS, PERIODS, NEWRANK, IERROR)
            INTEGER   COMM, NDIMS, DIMS(*), NEWRANK, IERROR
            LOGICAL   PERIODS(*)


CC++++ SSyynnttaaxx
       #include 
       int Cartcomm::Map(int ndims, const int dims[],
            const bool periods[]) const


IINNPPUUTT PPAARRAAMMEETTEERRSS
       comm      Input communicator (handle).

       ndims     Number of dimensions of Cartesian structure (integer).

       dims      Integer  array  of  size  ndims specifying the number of pro-
                 cesses in each coordinate direction.

       periods   Logical array of size ndims specifying the periodicity speci-
                 fication in each coordinate direction.


OOUUTTPPUUTT PPAARRAAMMEETTEERRSS
       newrank   Reordered rank of the calling process; MPIUNDEFINED if call-
                 ing process does not belong to grid (integer).

       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       MPICartmap and MPIGraphmap 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.

       MPICartmap 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.


EERRRROORRSS
       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::ERRORSTHROWEXCEPTIONS, 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
       MPICommseterrhandler; the predefined error handler MPIERRORSRETURN
       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
       MPIGraphmap



Open MPI 1.2                    September 2006          MPICartmap(3OpenMPI)