def test_no_contraction_if_each_edge_is_different(self):
g = self.create_graph(number_nodes=6)
g.add_edge(
Edge(s=0, t=1, forward=True, backward=True, data=self.edge_data(name="a"))
)
g.add_edge(
Edge(
s=1,
t=2,
forward=True,
backward=True,
data=self.edge_data(name="a", highway="b"),
)
)
g.add_edge(
Edge(
s=2,
t=3,
forward=True,
backward=False,
data=self.edge_data(name="a", highway="b"),
)
)
g.add_edge(
Edge(
s=3,
t=4,
forward=True,
backward=True,
data=self.edge_data(name="a", highway="b"),
)
)
g.add_edge(
Edge(
s=4,
t=5,
forward=True,
backward=True,
data=self.edge_data(name="a", highway="b", max_v=123),
)
)
contracted_graph = ContractGraph(g).contract()
self.assertEqual(len(contracted_graph.vertices), 6)
self.assertEqual(len(contracted_graph.edges), 5)
result_edge_data = [e.data for e in contracted_graph.edges]
expected_edge_data = [
self.edge_data(name="a"),
self.edge_data(name="a", highway="b"),
self.edge_data(name="a", highway="b"),
self.edge_data(name="a", highway="b"),
self.edge_data(name="a", highway="b", max_v=123),
]
self.assertCountEqual(result_edge_data, expected_edge_data)
def test_contract_a_path_to_two_nodes_and_one_edge(self):
g = self.create_graph(number_nodes=3)
g.add_edge(Edge(s=0, t=1, forward=True, backward=True, data=self.edge_data()))
g.add_edge(Edge(s=1, t=2, forward=True, backward=True, data=self.edge_data()))
contracted_graph = ContractGraph(g).contract()
self.assertEqual(len(contracted_graph.vertices), 2)
self.assertEqual(len(contracted_graph.edges), 1)
def test_three_vertex_should_three_edges_test(self):
v1 = Vertex(23, VertexData(1, 1))
v2 = Vertex(24, VertexData(2, 1))
v3 = Vertex(1, VertexData(5, 6))
e1 = Edge(v1.id, v2.id, True, True, EdgeData(123, "", 50, ""))
e2 = Edge(v2.id, v3.id, True, True, EdgeData(123, "", 50, ""))
e3 = Edge(v1.id, v3.id, True, True, EdgeData(123, "", 50, ""))
g = gf.build_graph_from_vertices_edges([v1, v2, v3], [e1, e2, e3])
self.assertTrue(len(g.vertices) == 3)
self.assertTrue(len(g.edges) == 3)
def test_add_edges_correct_in_out_neighbors_test(self):
g = Graph()
v1, v2, v3, v4 = (
self._get_vertex(0),
self._get_vertex(1),
self._get_vertex(2),
self._get_vertex(3),
)
e_forward = Edge(v1.id, v2.id, True, False, EdgeData(1, " ", 100, "Test"))
e_backward = Edge(v2.id, v3.id, False, True, EdgeData(1, " ", 100, "Test"))
e_nothing = Edge(v3.id, v4.id, False, False, EdgeData(1, " ", 100, "Test"))
e_both = Edge(v4.id, v1.id, True, True, EdgeData(1, " ", 100, "Test"))
g.add_node(v1)
g.add_node(v2)
g.add_node(v3)
g.add_node(v4)
g.add_edge(e_forward)
g.add_edge(e_backward)
g.add_edge(e_nothing)
g.add_edge(e_both)
self.assertEqual(len(g.edges), 4)
self.assertEqual(g.edges[0], e_forward)
self.assertEqual(g.edges[1], e_backward)
self.assertEqual(g.edges[2], e_nothing)
self.assertEqual(g.edges[3], e_both)
self.assertIn(e_forward.s, g.inneighbors[e_forward.t])
self.assertIn(e_forward.t, g.outneighbors[e_forward.s])
self.assertNotIn(e_forward.s, g.outneighbors[e_forward.t])
self.assertNotIn(e_forward.t, g.inneighbors[e_forward.s])
self.assertNotIn(e_backward.s, g.inneighbors[e_backward.t])
self.assertNotIn(e_backward.t, g.outneighbors[e_backward.s])
self.assertIn(e_backward.s, g.outneighbors[e_backward.t])
self.assertIn(e_backward.t, g.inneighbors[e_backward.s])
self.assertNotIn(e_nothing.s, g.inneighbors[e_nothing.t])
self.assertNotIn(e_nothing.t, g.outneighbors[e_nothing.s])
self.assertNotIn(e_nothing.s, g.outneighbors[e_nothing.t])
self.assertNotIn(e_nothing.t, g.inneighbors[e_nothing.s])
self.assertIn(e_both.s, g.inneighbors[e_both.t])
self.assertIn(e_both.t, g.outneighbors[e_both.s])
self.assertIn(e_both.s, g.outneighbors[e_both.t])
self.assertIn(e_both.t, g.inneighbors[e_both.s])
def test_contract_loop_to_nothing(self):
g = self.create_graph(number_nodes=4)
# loop
g.add_edge(Edge(s=0, t=1, forward=True, backward=True, data=self.edge_data()))
g.add_edge(Edge(s=1, t=2, forward=True, backward=True, data=self.edge_data()))
g.add_edge(Edge(s=2, t=0, forward=True, backward=True, data=self.edge_data()))
# connection (otherwise no intersections will be found)
g.add_edge(Edge(s=0, t=3, forward=True, backward=True, data=self.edge_data()))
contracted_graph = ContractGraph(g).contract()
self.assertEqual(len(contracted_graph.vertices), 2)
self.assertEqual(len(contracted_graph.edges), 1)
def test_two_vertex_should_fail_test(self):
v1 = Vertex(23, VertexData(1, 1))
v2 = Vertex(24, VertexData(2, 1))
e = Edge(21, 24, True, True, EdgeData(123, "", 50, ""))
g = gf.build_graph_from_vertices_edges([v1, v2], [e])
self.assertTrue(len(g.vertices) == 2)
self.assertTrue(len(g.edges) == 0)
def test_if_data_is_converted(self):
g = self.create_graph(number_nodes=2)
edge_data = self.edge_data()
g.add_edge(Edge(s=0, t=1, forward=True, backward=True, data=edge_data))
nx_graph = convert_to_networkx(g)
self.assertEqual(len(nx_graph.nodes), 2)
self.assertEqual(len(nx_graph.edges), 2)
nx_edges = nx_graph.edges(data=True)
e0, e1 = nx_edges
self.assertCountEqual([(e0[0], e0[1]), (e1[0], e1[1])], [(0, 1),
(1, 0)])
self.assertDictEqual(
e0[2],
{
"highway": edge_data.highway,
"length": edge_data.length,
"max_v": edge_data.max_v,
"name": edge_data.name,
},
)
self.assertDictEqual(
e1[2],
{
"highway": edge_data.highway,
"length": edge_data.length,
"max_v": edge_data.max_v,
"name": edge_data.name,
},
)
def test_two_vertex_should_be_one_edge_test(self):
v1 = Vertex(23, VertexData(1, 1))
v2 = Vertex(24, VertexData(2, 1))
e = Edge(23, 24, True, True, EdgeData(123, "", 50, ""))
g = gf.build_graph_from_vertices_edges([v1, v2], [e])
self.assertTrue(len(g.vertices) == 2)
self.assertTrue(len(g.edges) == 1)
self.assertEqual(g.edges[0].data.length, 123)
def add_edges_correct_in_out_neighbors_test(self):
g = Graph()
v1, v2, v3, v4 = self.get_vertex(0), self.get_vertex(
1), self.get_vertex(2), self.get_vertex(3)
e_forward = Edge(v1.id, v2.id, 1, " ", 100, True, False, "Test")
e_backward = Edge(v2.id, v3.id, 1, " ", 100, False, True, "Test")
e_nothing = Edge(v3.id, v4.id, 1, " ", 100, False, False, "Test")
e_both = Edge(v4.id, v1.id, 1, " ", 100, True, True, "Test")
g.add_node(v1)
g.add_node(v2)
g.add_node(v3)
g.add_node(v4)
g.add_edge(e_forward)
g.add_edge(e_backward)
g.add_edge(e_nothing)
g.add_edge(e_both)
self.assertEqual(len(g.edges), 4)
self.assertEqual(g.edges[0], e_forward)
self.assertEqual(g.edges[1], e_backward)
self.assertEqual(g.edges[2], e_nothing)
self.assertEqual(g.edges[3], e_both)
self.assertTrue(e_forward.s in g.inneighbors[e_forward.t])
self.assertTrue(e_forward.t in g.outneighbors[e_forward.s])
self.assertTrue(e_forward.s not in g.outneighbors[e_forward.t])
self.assertTrue(e_forward.t not in g.inneighbors[e_forward.s])
self.assertTrue(e_backward.s not in g.inneighbors[e_backward.t])
self.assertTrue(e_backward.t not in g.outneighbors[e_backward.s])
self.assertTrue(e_backward.s in g.outneighbors[e_backward.t])
self.assertTrue(e_backward.t in g.inneighbors[e_backward.s])
self.assertTrue(e_nothing.s not in g.inneighbors[e_nothing.t])
self.assertTrue(e_nothing.t not in g.outneighbors[e_nothing.s])
self.assertTrue(e_nothing.s not in g.outneighbors[e_nothing.t])
self.assertTrue(e_nothing.t not in g.inneighbors[e_nothing.s])
self.assertTrue(e_both.s in g.inneighbors[e_both.t])
self.assertTrue(e_both.t in g.outneighbors[e_both.s])
self.assertTrue(e_both.s in g.outneighbors[e_both.t])
self.assertTrue(e_both.t in g.inneighbors[e_both.s])
def test_add_edges_correct_set_of_neighbors_test(self):
g = Graph()
v1, v2, v3 = self._get_vertex(0), self._get_vertex(1), self._get_vertex(2)
e_forward = Edge(v1.id, v2.id, True, False, EdgeData(1, " ", 100, "Test"))
e_backward = Edge(v2.id, v3.id, False, True, EdgeData(1, " ", 100, "Test"))
e_both = Edge(v3.id, v1.id, True, True, EdgeData(1, " ", 100, "Test"))
g.add_node(v1)
g.add_node(v2)
g.add_node(v3)
g.add_edge(e_forward)
g.add_edge(e_backward)
g.add_edge(e_both)
self.assertTrue(self._checkEqual([v2.id, v3.id], g.all_neighbors(v1.id)))
self.assertTrue(self._checkEqual([v1.id, v3.id], g.all_neighbors(v2.id)))
self.assertTrue(self._checkEqual([v1.id, v2.id], g.all_neighbors(v3.id)))
def add_edge_adds_one_edge_test(self):
g = Graph()
v1, v2 = self.get_vertex(0), self.get_vertex(1)
e = Edge(v1.id, v2.id, 1, " ", 100, True, True, "Test")
g.add_node(v1)
g.add_node(v2)
g.add_edge(e)
self.assertEqual(len(g.edges), 1)
self.assertEqual(g.edges[0], e)
def test_add_edge_adds_one_edge_test(self):
g = Graph()
v1, v2 = self._get_vertex(0), self._get_vertex(1)
data = EdgeData(23.4, "", 100, "")
e = Edge(v1.id, v2.id, True, True, data)
g.add_node(v1)
g.add_node(v2)
g.add_edge(e)
self.assertEqual(len(g.edges), 1)
self.assertEqual(g.edges[0], e)
def test_converting_K4_graph(self):
g = self.create_graph(number_nodes=4)
g.add_edge(
Edge(s=0, t=1, forward=True, backward=True, data=self.edge_data()))
g.add_edge(
Edge(s=1, t=2, forward=True, backward=True, data=self.edge_data()))
g.add_edge(
Edge(s=2, t=3, forward=True, backward=True, data=self.edge_data()))
g.add_edge(
Edge(s=3, t=0, forward=True, backward=True, data=self.edge_data()))
g.add_edge(
Edge(s=1, t=3, forward=True, backward=True, data=self.edge_data()))
g.add_edge(
Edge(s=0, t=2, forward=True, backward=True, data=self.edge_data()))
nx_graph = convert_to_networkx(g)
self.assertEqual(len(nx_graph.nodes), 4)
self.assertEqual(len(nx_graph.edges), 12)
def test_contracting_stops_at_intersections(self):
g = self.create_graph(number_nodes=7)
# path of 5 nodes
g.add_edge(Edge(s=0, t=1, forward=True, backward=True, data=self.edge_data()))
g.add_edge(Edge(s=1, t=2, forward=True, backward=True, data=self.edge_data()))
g.add_edge(Edge(s=2, t=3, forward=True, backward=True, data=self.edge_data()))
g.add_edge(Edge(s=3, t=4, forward=True, backward=True, data=self.edge_data()))
# path of two nodes attached in the middle of the path above
g.add_edge(Edge(s=2, t=5, forward=True, backward=True, data=self.edge_data()))
g.add_edge(Edge(s=5, t=6, forward=True, backward=True, data=self.edge_data()))
# expected outcome: 4 nodes remain, and 3 edges, one deg 3 node, all others are deg 1 nodes
contracted_graph = ContractGraph(g).contract()
self.assertEqual(len(contracted_graph.vertices), 4)
self.assertEqual(len(contracted_graph.edges), 3)
nmb_neigbors = [len(contracted_graph.all_neighbors(n_id)) for n_id in range(4)]
self.assertCountEqual(nmb_neigbors, [3, 1, 1, 1])
def test_contracting_stops_if_edge_is_different(self):
g = self.create_graph(number_nodes=10)
g.add_edge(
Edge(
s=0,
t=1,
forward=True,
backward=True,
data=self.edge_data(length=2, name="abc"),
)
)
g.add_edge(
Edge(
s=1,
t=2,
forward=True,
backward=True,
data=self.edge_data(length=3, name="abc"),
)
)
g.add_edge(
Edge(
s=2,
t=3,
forward=True,
backward=True,
data=self.edge_data(length=5, name="def"),
)
)
g.add_edge(
Edge(
s=3,
t=4,
forward=True,
backward=True,
data=self.edge_data(length=7, name="def"),
)
)
g.add_edge(
Edge(
s=4,
t=5,
forward=True,
backward=True,
data=self.edge_data(length=11, name="ghi"),
)
)
g.add_edge(
Edge(
s=5,
t=6,
forward=True,
backward=True,
data=self.edge_data(length=13, name="ghi"),
)
)
g.add_edge(
Edge(
s=6,
t=7,
forward=True,
backward=True,
data=self.edge_data(length=17, name="jkl"),
)
)
g.add_edge(
Edge(
s=7,
t=8,
forward=True,
backward=True,
data=self.edge_data(length=23, name="mno"),
)
)
g.add_edge(
Edge(
s=8,
t=9,
forward=True,
backward=True,
data=self.edge_data(length=29, name="mno"),
)
)
# input: 0-1-2-3-4-5-6-7-8-9
# expected outcome: 0-2-4-6-7-9
contracted_graph = ContractGraph(g).contract()
self.assertEqual(len(contracted_graph.vertices), 6)
self.assertEqual(len(contracted_graph.edges), 5)
result_edge_data = [e.data for e in contracted_graph.edges]
expected_edge_data = [
self.edge_data(length=5, name="abc"),
self.edge_data(length=12, name="def"),
self.edge_data(length=24, name="ghi"),
self.edge_data(length=17, name="jkl"),
self.edge_data(length=52, name="mno"),
]
self.assertCountEqual(result_edge_data, expected_edge_data)
def _find_new_edges(self) -> Set[Edge]:
# maintain a list L of nodes from which we want to start searches to find new contracted edges
# initialize L with all intersection nodes (i.e., all nodes with degree != 2)
# for each node n in L
# for each of n's neighbor
# search until:
# - an intersection node is found or edge is found
# - the next edge is different in it's structure (e.g., different highway type, different max speed, ...)
self.start_nodes = self._find_all_intersections()
self.seen_start_nodes = set(self.start_nodes)
new_edges = set()
bidirectional_edges: Set[Tuple[int, int]] = set()
out_edges_per_node = self._get_out_edges()
while len(self.start_nodes) > 0:
node_id = self.start_nodes.popleft()
out_edges = out_edges_per_node[node_id]
for first_out_edge in out_edges:
start_node_id = node_id
edges_to_merge, final_node_id = self._find_edges_to_merge(
start_node_id, first_out_edge
)
if len(edges_to_merge) == 0:
continue
sum_edge_lengths = sum([e.data.length for e in edges_to_merge])
data = replace(edges_to_merge[0].data, length=sum_edge_lengths)
if edges_to_merge[0].backward:
# deduplication measure; if not for this for bidirectional edges, that are
# removed between intersections, 2 new edges would be created
smaller_node_id = (
start_node_id
if start_node_id < final_node_id
else final_node_id
)
bigger_node_id = (
start_node_id
if start_node_id > final_node_id
else final_node_id
)
if (smaller_node_id, bigger_node_id) in bidirectional_edges:
# already added this edge skip it
continue
bidirectional_edges.add((smaller_node_id, bigger_node_id))
merged_edge = Edge(
smaller_node_id,
bigger_node_id,
True,
edges_to_merge[0].backward,
data,
)
else:
merged_edge = Edge(
start_node_id,
final_node_id,
True,
edges_to_merge[0].backward,
data,
)
new_edges.add(merged_edge)
return new_edges
