def test_complete_graph(self):
N = 50
G = nx.complete_graph(N)
for (u, v) in G.edges():
G[u][v]['capacity'] = 5
assert_equal(nx.ford_fulkerson(G, 1, 2)[0], 5 * (N - 1))
assert_equal(nx.preflow_push(G, 1, 2)[0], 5 * (N - 1))
def test_preflow_push_global_relabel_freq():
G = nx.DiGraph()
G.add_edge(1, 2, capacity=1)
R = nx.preflow_push(G, 1, 2, global_relabel_freq=None)
assert_equal(R.graph['flow_value'], 1)
assert_raises(nx.NetworkXError, preflow_push, G, 1, 2,
global_relabel_freq=-1)
def _test_graph(self, G, s, t, soln, pred=assert_equal):
validate = partial(validate_flows, G, s, t, soln, pred=pred)
#validate(*nx.ford_fulkerson(G, s, t))
validate(*nx.edmonds_karp(G, s, t))
validate(*nx.preflow_push(G, s, t))
validate(*nx.shortest_augmenting_path(G, s, t, two_phase=False))
validate(*nx.shortest_augmenting_path(G, s, t, two_phase=True))
def _test_graph(self, G, s, t, soln, pred=assert_equal):
validate = partial(validate_flows, G, s, t, soln, pred=pred)
#validate(*nx.ford_fulkerson(G, s, t))
validate(*nx.edmonds_karp(G, s, t))
validate(*nx.preflow_push(G, s, t))
validate(*nx.shortest_augmenting_path(G, s, t, two_phase=False))
validate(*nx.shortest_augmenting_path(G, s, t, two_phase=True))
def test_preflow_push_global_relabel_freq(self):
G = nx.DiGraph()
G.add_edge(1, 2, capacity=1)
assert_equal(nx.preflow_push(G, 1, 2, global_relabel_freq=None)[0], 1)
assert_raises(nx.NetworkXError,
nx.preflow_push_value,
G,
1,
2,
global_relabel_freq=-1)
def test_pyramid(self):
N = 10
# N = 100 # this gives a graph with 5051 nodes
G = gen_pyramid(N)
assert_almost_equal(nx.ford_fulkerson(G, (0, 0), 't')[0], 1.)
assert_almost_equal(nx.preflow_push(G, (0, 0), 't')[0], 1.)
assert_almost_equal(nx.shortest_augmenting_path(
G, (0, 0), 't', two_phase=False)[0], 1.)
assert_almost_equal(nx.shortest_augmenting_path(
G, (0, 0), 't', two_phase=True)[0], 1.)
def compare_flows(G, s, t, solnFlows, solnValue, capacity = 'capacity'):
flowValue, flowDict = nx.ford_fulkerson(G, s, t, capacity)
assert_equal(flowValue, solnValue)
assert_equal(flowDict, solnFlows)
flowValue, flowDict = nx.preflow_push(G, s, t, capacity)
assert_equal(flowValue, solnValue)
validate_flows(G, s, t, flowDict, solnValue, capacity)
assert_equal(nx.min_cut(G, s, t, capacity), solnValue)
assert_equal(nx.max_flow(G, s, t, capacity), solnValue)
assert_equal(nx.ford_fulkerson_flow(G, s, t, capacity), solnFlows)
def test_complete_graph(self):
N = 50
G = nx.complete_graph(N)
for (u, v) in G.edges():
G[u][v]['capacity'] = 5
assert_equal(nx.ford_fulkerson(G, 1, 2)[0], 5 * (N - 1))
assert_equal(nx.preflow_push(G, 1, 2)[0], 5 * (N - 1))
assert_equal(nx.shortest_augmenting_path(G, 1, 2, two_phase=False)[0],
5 * (N - 1))
assert_equal(nx.shortest_augmenting_path(G, 1, 2, two_phase=True)[0],
5 * (N - 1))
def test_preflow_push_global_relabel_freq():
G = nx.DiGraph()
G.add_edge(1, 2, capacity=1)
R = nx.preflow_push(G, 1, 2, global_relabel_freq=None)
assert_equal(R.graph['flow_value'], 1)
assert_raises(nx.NetworkXError,
preflow_push,
G,
1,
2,
global_relabel_freq=-1)
def compare_flows(G, s, t, solnFlows, solnValue, capacity = 'capacity'):
flowValue, flowDict = nx.ford_fulkerson(G, s, t, capacity)
assert_equal(flowValue, solnValue)
assert_equal(flowDict, solnFlows)
flowValue, flowDict = nx.preflow_push(G, s, t, capacity)
assert_equal(flowValue, solnValue)
validate_flows(G, s, t, flowDict, solnValue, capacity)
flowValue, flowDict = nx.shortest_augmenting_path(G, s, t, capacity,
two_phase=False)
assert_equal(flowValue, solnValue)
validate_flows(G, s, t, flowDict, solnValue, capacity)
flowValue, flowDict = nx.shortest_augmenting_path(G, s, t, capacity,
two_phase=True)
assert_equal(flowValue, solnValue)
validate_flows(G, s, t, flowDict, solnValue, capacity)
assert_equal(nx.min_cut(G, s, t, capacity), solnValue)
assert_equal(nx.max_flow(G, s, t, capacity), solnValue)
assert_equal(nx.ford_fulkerson_flow(G, s, t, capacity), solnFlows)
def compare_flows(G, s, t, solnFlows, solnValue, capacity='capacity'):
flowValue, flowDict = nx.ford_fulkerson(G, s, t, capacity)
assert_equal(flowValue, solnValue)
assert_equal(flowDict, solnFlows)
flowValue, flowDict = nx.preflow_push(G, s, t, capacity)
assert_equal(flowValue, solnValue)
validate_flows(G, s, t, flowDict, solnValue, capacity)
flowValue, flowDict = nx.shortest_augmenting_path(G,
s,
t,
capacity,
two_phase=False)
assert_equal(flowValue, solnValue)
validate_flows(G, s, t, flowDict, solnValue, capacity)
flowValue, flowDict = nx.shortest_augmenting_path(G,
s,
t,
capacity,
two_phase=True)
assert_equal(flowValue, solnValue)
validate_flows(G, s, t, flowDict, solnValue, capacity)
assert_equal(nx.min_cut(G, s, t, capacity), solnValue)
assert_equal(nx.max_flow(G, s, t, capacity), solnValue)
assert_equal(nx.ford_fulkerson_flow(G, s, t, capacity), solnFlows)
def test_preflow_push_global_relabel(self):
G = read_graph('gw1')
assert_equal(nx.preflow_push(G, 1, len(G), global_relabel_freq=50)[0],
1202018)
def test_preflow_push_global_relabel_freq(self):
G = nx.DiGraph()
G.add_edge(1, 2, capacity=1)
assert_equal(nx.preflow_push(G, 1, 2, global_relabel_freq=None)[0], 1)
assert_raises(nx.NetworkXError, nx.preflow_push_value, G, 1, 2,
global_relabel_freq=-1)
def test_pyramid(self):
N = 10
# N = 100 # this gives a graph with 5051 nodes
G = gen_pyramid(N)
assert_almost_equal(nx.ford_fulkerson(G, (0, 0), 't')[0], 1.)
assert_almost_equal(nx.preflow_push(G, (0, 0), 't')[0], 1.)
def test_preflow_push_global_relabel(self):
G = read_graph('gw1')
R = nx.preflow_push(G, 1, len(G), global_relabel_freq=50)
assert_equal(R.graph['flow_value'], 1202018)
def test_preflow_push_global_relabel(self):
G = read_graph('gw1')
R = nx.preflow_push(G, 1, len(G), global_relabel_freq=50)
assert_equal(R.graph['flow_value'], 1202018)