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MPI_Graphdims_get(3OpenMPI)                                                      MPI_Graphdims_get(3OpenMPI)



NAME
       MPI_Graphdims_get  - Retrieves graph topology information associated with a communicator.


SYNTAX
C Syntax
       #include <mpi.h>
       int MPI_Graphdims_get(MPI_Comm comm, int *nnodes, int *nedges)


Fortran Syntax
       INCLUDE 'mpif.h'
       MPI_GRAPHDIMS_GET(COMM, NNODES, NEDGES, IERROR)
            INTEGER   COMM, NNODES, NEDGES, IERROR


C++ Syntax
       #include <mpi.h>
       void Graphcomm::Get dims(int nnodes[], int nedges[]) const


INPUT PARAMETER
       comm      Communicator for group with graph structure (handle).


OUTPUT PARAMETERS
       nnodes    Number of nodes in graph (integer).

       nedges    Number of edges in graph (integer).

       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       Functions  MPI_Graphdims_get and MPI_Graph_get retrieve the graph-topology information that was asso-ciated associated
       ciated with a communicator by MPI_Graph_create.

       The information provided by MPI_Graphdims_get can be used to dimension the vectors  index  and  edges
       correctly for a call to MPI_Graph_get.


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_Graph_create
       MPI_Graph_get




Open MPI 1.2                                   September 2006                    MPI_Graphdims_get(3OpenMPI)