MPI_Dist_graph_neighbors(3) Open MPI MPI_Dist_graph_neighbors(3)NAMEMPI_Dist_graph_neighbors - Returns the neighbors of the calling
process in a distributed graph topology.
SYNTAXC Syntax
#include <mpi.h>
int MPI_Dist_graph_neighbors(MPI_Comm comm, int maxindegree, int sources[], int sourceweights[],
int maxoutdegree, int destinations[], int destweights[])
Fortran Syntax
INCLUDE 'mpif.h'
MPI_DIST_GRAPH_NEIGHBORS(COMM, MAXINDEGREE, SOURCES, SOURCEWEIGHTS,
MAXOUTDEGREE, DESTINATIONS, DESTWEIGHTS, IERROR)
INTEGER COMM, MAXINDEGREE, SOURCES(*), SOURCEWEIGHTS(*), MAXOUTDEGREE,
DESTINATIONS(*), DESTWEIGHTS(*), IERROR
INPUT PARAMETERS
comm Communicator with distributed graph topology (handle).
maxindegree
Size of sources and sourceweights arrays (non-negative inte‐
ger).
maxoutdegree
Size of destinations and destweights arrays (non-negative
integer).
OUTPUT PARAMETERS
sources Processes for which the calling process is a destination
(array of non-negative integers).
sourceweights
Weights of the edges into the calling process (array of non-
negative integers).
destinations
Processes for which the calling process is a source (array of
non-negative integers).
destweights
Weights of the edges out of the calling process (array of
non-negative integers).
IERROR Fortran only: Error status (integer).
DESCRIPTIONMPI_Dist_graph_neighbors returns the source and destination ranks in a
distributed graph topology for the calling process. This call will
return up to maxindegree source ranks in the sources array and up to
maxoutdegree destination ranks in the destinations array. If weights
were specified at the time of the communicator's creation then the
associated weights are returned in the sourceweights and destweights
arrays. If the communicator was created with MPI_Dist_graph_cre‐
ate_adjacent then the order of the values in sources and destinations
is identical to the input that was used by the process with the same
rank in comm_old in the creation call.
ERRORS
Almost all MPI routines return an error value; C routines as the value
of the function and Fortran routines in the last argument.
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_Dist_graph_neighbors_count
1.7.4 Feb 04, 2014 MPI_Dist_graph_neighbors(3)
