def main(args):
parser = argparse.ArgumentParser()
parser.add_argument('output',
metavar='graph.pickle',
help='Ouput graph file')
parser.add_argument(
'--connection',
default='postgresql://*****:*****@localhost/osrm',
help='Postgres connection string. Default %(default)s')
parser.add_argument('--prune',
action='store_true',
help='Collapse redundant edges, prune tails')
parser.add_argument('--verbose',
action='store_true',
help='Increase logging level')
args = parser.parse_args()
logging.basicConfig(
level=logging.INFO if args.verbose else logging.WARNING)
log.info("Creating DB engine")
engine = create_engine(args.connection, echo=False)
log.info("Creating DB session")
Session = sessionmaker(bind=engine)
session = Session()
g = build_graph(session)
if args.prune:
log.info("Collapsing unidirectional strings")
pruned = graphtools.collapse_degree_2_vtxs(g)
log.info("Removed %i thru-nodes", pruned)
log.info("Collapsing bidirectional strings")
pruned = graphtools.collapse_bidirectional_streets(g)
log.info("Removed %i thru-nodes", pruned)
log.info("Snipping tails")
snipped = graphtools.delete_degree_1_vtxs(g)
log.info("Removed %i tails", snipped)
loners = graphtools.delete_degree_0_vtxs(g)
log.info("Removed %i loner-nodes (should be zero)", loners)
redundancies = graphtools.identify_rendudant_nodes(g)
log.info("Marked %i nodes as redundant", redundancies)
log.info("Saving graph to %s", args.output)
g.save(args.output)
def main(args):
parser = argparse.ArgumentParser()
parser.add_argument('output', metavar='graph.pickle',
help='Ouput graph file')
parser.add_argument(
'--connection',
default='postgresql://*****:*****@localhost/osrm',
help='Postgres connection string. Default %(default)s'
)
parser.add_argument('--prune', action='store_true',
help='Collapse redundant edges, prune tails')
parser.add_argument('--verbose', action='store_true',
help='Increase logging level')
args = parser.parse_args()
logging.basicConfig(
level=logging.INFO if args.verbose else logging.WARNING)
log.info("Creating DB engine")
engine = create_engine(args.connection, echo=False)
log.info("Creating DB session")
Session = sessionmaker(bind=engine)
session = Session()
g = build_graph(session)
if args.prune:
log.info("Collapsing unidirectional strings")
pruned = graphtools.collapse_degree_2_vtxs(g)
log.info("Removed %i thru-nodes", pruned)
log.info("Collapsing bidirectional strings")
pruned = graphtools.collapse_bidirectional_streets(g)
log.info("Removed %i thru-nodes", pruned)
log.info("Snipping tails")
snipped = graphtools.delete_degree_1_vtxs(g)
log.info("Removed %i tails", snipped)
loners = graphtools.delete_degree_0_vtxs(g)
log.info("Removed %i loner-nodes (should be zero)", loners)
redundancies = graphtools.identify_rendudant_nodes(g)
log.info("Marked %i nodes as redundant", redundancies)
log.info("Saving graph to %s", args.output)
g.save(args.output)
def test_delete_degree_1_vtxs():
g = igraph.Graph(directed=True)
# a square with a tail
g.add_vertices(5)
g.add_edges([
(0, 1),
(1, 2),
(2, 3),
(3, 0),
(2, 4) # the tail
])
eq_(len(g.vs), 5)
eq_(len(g.es), 5)
eq_(len(g.vs.select(_degree_eq=1)), 1)
eq_(len(g.vs.select(_degree_eq=2)), 3)
eq_(len(g.vs.select(_degree_eq=3)), 1)
ret = gt.delete_degree_1_vtxs(g)
eq_(ret, 1)
# Now it is clean
eq_(len(g.vs), 4)
eq_(len(g.es), 4)
eq_(len(g.vs.select(_degree_eq=1)), 0)
eq_(len(g.vs.select(_degree_eq=2)), 4)
eq_(len(g.vs.select(_degree_eq=3)), 0)