def test_wheel(self):
G = self.graph_factory.make_wheel(n=self.N, directed=False)
self.assertFalse(G.is_directed())
self.assertEqual(G.v(), self.N)
self.assertEqual(G.e(), 2 * self.N - 2)
self.assertTrue(is_wheel(G))
self.assertRaises(ValueError, self.graph_factory.make_wheel, 1)
self.assertRaises(ValueError, self.graph_factory.make_wheel, 2)
self.assertRaises(ValueError, self.graph_factory.make_wheel, 3)
def test_wheel_true(self):
v = 10
G = Graph(v, False)
for node in range(v):
G.add_node(node)
hub = 0
for node in range(1, v):
G.add_edge(Edge(hub, node))
G.add_edge(Edge(node, node+1 if node < v-1 else 1))
self.assertTrue(is_wheel(G))
algorithm = WheelGraph(G)
algorithm.run()
self.assertEqual(algorithm.hub, hub)
def test_wheel(self):
G = self.graph_factory.make_wheel(n=self.N, directed=False)
self.assertFalse(G.is_directed())
self.assertEqual(G.v(), self.N)
self.assertEqual(G.e(), 2 * self.N - 2)
self.assertTrue(is_wheel(G))
faces = list(G.iterfaces())
self.assertEqual(G.f(), self.N)
self.assertEqual(len(faces), self.N)
#print "faces", faces
self.assertRaises(ValueError, self.graph_factory.make_wheel, 1)
self.assertRaises(ValueError, self.graph_factory.make_wheel, 2)
self.assertRaises(ValueError, self.graph_factory.make_wheel, 3)
def test_wheel(self):
G = self.graph_factory.make_wheel(n=self.N)
self.assertFalse(G.is_directed())
self.assertEqual(G.v(), self.N)
self.assertEqual(G.e(), 2 * self.N - 2)
self.assertTrue(is_wheel(G))
faces = list(G.iterfaces())
self.assertEqual(G.f(), self.N)
self.assertEqual(len(faces), self.N)
#print "faces", faces
self.assertRaises(ValueError, self.graph_factory.make_wheel, 1)
self.assertRaises(ValueError, self.graph_factory.make_wheel, 2)
self.assertRaises(ValueError, self.graph_factory.make_wheel, 3)
def test_wheel_false2(self):
# 1---2 missing Edge(0, 3) or Edge(1, 3)
# |\ /|
# | 0 |
# |/ |
# 4---3
v = 5
G = Graph(v, False)
for node in range(v):
G.add_node(node)
edges = [
Edge(0, 1), Edge(0, 2), Edge(0, 4),
Edge(1, 2), Edge(2, 3), Edge(3, 4), Edge(1, 4)]
for edge in edges:
G.add_edge(edge)
G.add_edge(Edge(2, 4)) # bad edge
self.assertFalse(is_wheel(G))
self.assertRaises(ValueError, lambda: WheelGraph(G).run())
def test_wheel_false(self):
# 0---+ +---5 windmill graph
# |\ \ / /| https://en.wikipedia.org/wiki/Windmill_graph
# | 1---3---4 |
# |/ / \ \|
# 2---+ +---6
v = 7
G = Graph(v, False)
for node in range(v):
G.add_node(node)
edges = [
Edge(0, 1), Edge(1, 2), Edge(0, 2), Edge(4, 5),
Edge(5, 6), Edge(4, 6), Edge(0, 3), Edge(1, 3),
Edge(2, 3), Edge(3, 5), Edge(3, 4), Edge(3, 6)]
for edge in edges:
G.add_edge(edge)
self.assertFalse(is_wheel(G))
self.assertRaises(ValueError, lambda: WheelGraph(G).run())
def test_is_wheel(self):
G = self.graph_factory.make_complete(n=3, directed=False)
self.assertFalse(is_wheel(G))
self.assertRaises(ValueError, lambda: WheelGraph(G).run())
def test_k4(self): # complete graph K4 = W4
G = self.graph_factory.make_complete(n=4, directed=False)
self.assertTrue(is_wheel(G))
algorithm = WheelGraph(G)
algorithm.run()
self.assertEqual(algorithm.hub, 0)
#!/usr/bin/python
from graphtheory.structures.edges import Edge
from graphtheory.structures.graphs import Graph
from graphtheory.structures.factory import GraphFactory
from graphtheory.planarity.halin import HalinGraph
from graphtheory.planarity.wheels import is_wheel
V = 10
graph_factory = GraphFactory(Graph)
#G = graph_factory.make_prism(size=3) # V=2*size=6
#G = graph_factory.make_complete(n=4) # V=4
#G = graph_factory.make_wheel(n=V) # V > 3
G = graph_factory.make_necklace(n=V) # V even
G.show()
print ( "Recognition ..." )
print ( "is_wheel {}".format( is_wheel(G) ))
algorithm = HalinGraph(G)
algorithm.run()
print ( "outer {}".format( algorithm.outer ))
outer = algorithm.outer
#assert outer == set(range(1,V)) # wheel
assert outer == set(range(0,V,2)) | set([V-1]) # necklace
# EOF
from graphtheory.planarity.halinnodecolor import HalinNodeColoring
from graphtheory.planarity.halintools import make_halin
from graphtheory.planarity.halintools import make_halin_cubic
from graphtheory.planarity.wheels import is_wheel
graph_factory = GraphFactory(Graph)
#G = graph_factory.make_prism(size=3) # V=2*size=6
#G = graph_factory.make_complete(n=4) # V=4
#G = graph_factory.make_wheel(n=5) # V > 3
G = graph_factory.make_necklace(n=6) # V even
#G = make_halin(n=7) # V > 3
#G = make_halin_cubic(n=8) # V even
G.show()
print("Recognition ...")
print("is_wheel {}".format(is_wheel(G)))
algorithm = HalinGraph(G)
algorithm.run()
print("outer {}".format(algorithm.outer))
outer = algorithm.outer
print("Vertex coloring ...")
algorithm = HalinNodeColoring(G, outer)
algorithm.run()
print("parent {}".format(algorithm.parent))
assert len(algorithm.parent) == G.v()
print("color {}".format(algorithm.color))
all_colors = set(algorithm.color[node] for node in G.iternodes())
print("len(all_colors) {}".format(len(all_colors)))
assert len(algorithm.color) == G.v()
