MPI_Graphdims_get(3)               Open MPI               MPI_Graphdims_get(3)



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 associated 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




1.4.1                            Jan 14, 2010             MPI_Graphdims_get(3)
