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.. _mpi_graphdims_get:
MPI_Graphdims_get
=================
.. include_body
:ref:`MPI_Graphdims_get` |mdash| Retrieves graph topology information associated with
a communicator.
SYNTAX
------
C Syntax
^^^^^^^^
.. code-block:: c
#include <mpi.h>
int MPI_Graphdims_get(MPI_Comm comm, int *nnodes, int *nedges)
Fortran Syntax
^^^^^^^^^^^^^^
.. code-block:: fortran
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_GRAPHDIMS_GET(COMM, NNODES, NEDGES, IERROR)
INTEGER COMM, NNODES, NEDGES, IERROR
Fortran 2008 Syntax
^^^^^^^^^^^^^^^^^^^
.. code-block:: fortran
USE mpi_f08
MPI_Graphdims_get(comm, nnodes, nedges, ierror)
TYPE(MPI_Comm), INTENT(IN) :: comm
INTEGER, INTENT(OUT) :: nnodes, nedges
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
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 :ref:`MPI_Graphdims_get` and :ref:`MPI_Graph_get` retrieve the
graph-topology information that was associated with a communicator by
:ref:`MPI_Graph_create`.
The information provided by :ref:`MPI_Graphdims_get` can be used to dimension
the vectors index and edges correctly for a call to :ref:`MPI_Graph_get`.
ERRORS
------
.. include:: ./ERRORS.rst
.. seealso:: :ref:`MPI_Graph_create`
|
