MPI_Graph_neighbors_count(3) Open MPI MPI_Graph_neighbors_count(3)NAMEMPI_Graph_neighbors_count - Returns the number of neighbors of a node
associated with a graph topology.
SYNTAXC Syntax
#include <mpi.h>
int MPI_Graph_neighbors_count(MPI_Comm comm, int rank,
int *nneighbors)
Fortran Syntax
INCLUDE 'mpif.h'
MPI_GRAPH_NEIGHBORS_COUNT(COMM, RANK, NNEIGHBORS, IERROR)
INTEGER COMM, RANK, NNEIGHBORS, IERROR
C++ Syntax
#include <mpi.h>
int Graphcomm::Get_neighbors_count(int rank) const
INPUT PARAMETERS
comm Communicator with graph topology (handle).
rank Rank of process in group of comm (integer).
OUTPUT PARAMETERS
nneighbors
Number of neighbors of specified process (integer).
IERROR Fortran only: Error status (integer).
DESCRIPTIONMPI_Graph_neighbors_count and MPI_Graph_neighbors provide adjacency
information for a general, graph topology. MPI_Graph_neighbors_count
returns the number of neighbors for the process signified by rank.
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++ func‐
tions 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_neighbors
1.7.4 Feb 04, 2014 MPI_Graph_neighbors_count(3)
