MPICartcreate(3OpenMPI) MPICartcreate(3OpenMPI)

NAME
       MMPPIICCaarrttccrreeaattee  - Makes a new communicator to which Cartesian topology
       information has been attached.


SSYYNNTTAAXX
CC SSyynnttaaxx
       #include 
       int MPICartcreate(MPIComm commold, int ndims, int *dims,
            int *periods, int reorder, MPIComm *commcart)


FFoorrttrraann SSyynnttaaxx
       INCLUDE 'mpif.h'
       MPICARTCREATE(COMMOLD, NDIMS, DIMS, PERIODS, REORDER,
                 COMMCART, IERROR)
            INTEGER   COMMOLD, NDIMS, DIMS(*), COMMCART, IERROR
            LOGICAL   PERIODS(*), REORDER


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


IINNPPUUTT PPAARRAAMMEETTEERRSS
       commold  Input communicator (handle).

       ndims     Number of dimensions of Cartesian grid (integer).

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

       periods   Logical  array  of  size ndims specifying whether the grid is
                 periodic (true) or not (false) in each dimension.

       reorder   Ranking may be reordered (true) or not (false) (logical).


OOUUTTPPUUTT PPAARRAAMMEETTEERRSS
       commcart Communicator with new Cartesian topology (handle).

       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       MPICartcreate returns a handle to a new  communicator  to  which  the
       Cartesian topology information is attached. If reorder = false then the
       rank of each process in the new group is identical to its rank  in  the
       old  group. Otherwise, the function may reorder the processes (possibly
       so as to choose a good embedding of the virtual topology onto the phys-
       ical  machine). If the total size of the Cartesian grid is smaller than
       the size of the  group  of  comm,  then  some  processes  are  returned
       MPICOMMNULL,  in  analogy to MPICommsplit. The call is erroneous if
       it specifies a grid that is larger than the group size.


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.




Open MPI 1.2                    September 2006       MPICartcreate(3OpenMPI)