int MPI_Dist_graph_create(MPI_Comm comm_old, int n, const int sources[], const int degrees[], const int destinations[], const int weights[], MPI_Info info, int reorder, MPI_Comm *comm_dist_graph)

**comm_old**- input communicator (handle)
**n**- number of source nodes for which this process specifies edges (non-negative integer)
**sources**- array containing the n source nodes for which this process specifies edges (array of non-negative integers)
**degrees**- array specifying the number of destinations for each source node in the source node array (array of non-negative integers)
**destinations**- destination nodes for the source nodes in the source node array (array of non-negative integers)
**weights**- weights for source to destination edges (array of non-negative integers or MPI_UNWEIGHTED)
**info**- hints on optimization and interpretation of weights (handle)
**reorder**- the process may be reordered (true) or not (false) (logical)

**comm_dist_graph**- communicator with distributed graph topology added (handle)

This routine is thread-safe. This means that this routine may be
safely used by multiple threads without the need for any user-provided
thread locks. However, the routine is not interrupt safe. Typically,
this is due to the use of memory allocation routines such as `malloc
`or other non-MPICH runtime routines that are themselves not interrupt-safe.

All MPI objects (e.g., `MPI_Datatype`, `MPI_Comm`) are of type `INTEGER
`in Fortran.

All MPI routines (except `MPI_Wtime` and `MPI_Wtick`) return an error value;
C routines as the value of the function and Fortran routines in the last
argument. Before the value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job. The error handler
may be changed with `MPI_Comm_set_errhandler` (for communicators),
`MPI_File_set_errhandler` (for files), and `MPI_Win_set_errhandler` (for
RMA windows). The MPI-1 routine `MPI_Errhandler_set` may be used but
its use is deprecated. The predefined error handler
`MPI_ERRORS_RETURN` may be used to cause error values to be returned.
Note that MPI does *not* guarentee that an MPI program can continue past
an error; however, MPI implementations will attempt to continue whenever
possible.

**MPI_SUCCESS**- No error; MPI routine completed successfully.

**MPI_ERR_ARG**- Invalid argument. Some argument is invalid and is not
identified by a specific error class (e.g.,
`MPI_ERR_RANK`).

**MPI_ERR_OTHER**- Other error; use
`MPI_Error_string`to get more information about this error code.

**Location:**src/mpi/topo/dist_gr_create.c