def testNeighbors(self): # Directed G = nk.Graph(4, False, True) G.addEdge(0, 1) G.addEdge(0, 2) G.addEdge(3, 1) G.addEdge(3, 2) G.addEdge(1, 2) self.assertEqual(sorted(G.neighbors(0)), [1, 2]) self.assertEqual(sorted(G.neighbors(1)), [2]) self.assertEqual(sorted(G.neighbors(2)), []) self.assertEqual(sorted(G.neighbors(3)), [1, 2]) # Undirected G = nk.Graph(4, False, False) G.addEdge(0, 1) G.addEdge(0, 2) G.addEdge(3, 1) G.addEdge(3, 2) G.addEdge(1, 2) self.assertEqual(sorted(G.neighbors(0)), [1, 2]) self.assertEqual(sorted(G.neighbors(1)), [0, 2, 3]) self.assertEqual(sorted(G.neighbors(2)), [0, 1, 3]) self.assertEqual(sorted(G.neighbors(3)), [1, 2])
def testIterator(self):
# Undirected
G = nk.Graph(4, False, False)
G.addEdge(0, 1)
G.addEdge(0, 2)
G.addEdge(1, 2)
G.addEdge(3, 1)
G.addEdge(3, 2)
def nbrFunc(u, v, weight, edgeId):
forEdgesNbrs.append(v)
# Iterate through neighbours of node using iterNeighbors
def nodeIter(node):
nodeList = []
nbrs = G.iterNeighbors(node)
try:
while nbrs is not None:
nodeList.append(next(nbrs))
except StopIteration:
pass
return nodeList
for node in range(G.upperNodeIdBound()):
forEdgesNbrs = []
G.forEdgesOf(node, nbrFunc)
nodeNbrs = nodeIter(node)
self.assertEqual(sorted(forEdgesNbrs), sorted(nodeNbrs))
# Directed
G = nk.Graph(4, False, True)
G.addEdge(0, 1)
G.addEdge(0, 2)
G.addEdge(3, 1)
G.addEdge(3, 2)
G.addEdge(1, 2)
# Iterate through neighbours of node using iterNeighbors
def nodeInIter(node):
nodeList = []
nbrs = G.iterInNeighbors(node)
try:
while nbrs is not None:
nodeList.append(next(nbrs))
except StopIteration:
pass
return nodeList
for node in range(G.upperNodeIdBound()):
forEdgesNbrs = []
G.forInEdgesOf(node, nbrFunc)
nodeInNbrs = nodeInIter(node)
self.assertEqual(sorted(forEdgesNbrs), sorted(nodeInNbrs))
def testAddEdgeWithMissingNodes(self):
G = nk.Graph(0)
with self.assertRaises(RuntimeError):
G.addEdge(0, 1)
self.assertEqual(G.numberOfNodes(), 0)
self.assertEqual(G.numberOfEdges(), 0)
G.addEdge(0, 2, addMissing=True)
self.assertEqual(G.numberOfNodes(), 3)
self.assertEqual(G.numberOfEdges(), 1)
G.removeNode(1)
self.assertEqual(G.numberOfNodes(), 2)
self.assertEqual(G.numberOfEdges(), 1)
G.addEdge(0, 1, addMissing=True)
self.assertEqual(G.numberOfNodes(), 3)
self.assertEqual(G.numberOfEdges(), 2)
G.removeNode(2)
G.addEdge(1, 2, addMissing=True)
self.assertEqual(G.numberOfNodes(), 3)
self.assertEqual(G.numberOfEdges(), 2)
def testDegreePreservingShuffleDirectedTriangle(self):
"""Test whether a directed triangle is reoriented in 50% of cases"""
G = nk.Graph(3, False, True)
G.addEdge(0, 1)
G.addEdge(1, 2)
G.addEdge(2, 0)
num_clockwise = 0
num_iterations = 1000
for i in range(num_iterations):
dps = nk.randomization.DegreePreservingShuffle(G)
dps.run()
G2 = dps.getGraph()
check_graphs(G, G2)
# check orientation
clockwise = G2.hasEdge(0, 1)
anticlkw = G2.hasEdge(1, 0)
self.assertNotEqual(clockwise, anticlkw)
num_clockwise += clockwise
G = G2
# confidence interval with an error rate of ~ 1e-6
self.assertGreater(num_clockwise, 400)
self.assertLess(num_clockwise, 600)
def fit_ba(g, fully_connected_start):
random.seed(42, version=2)
networkit.setSeed(seed=42, useThreadId=False)
n, m = g.size()
m_0 = math.ceil(m / n)
ba = networkit.Graph(n)
nodes = ba.nodes()
edges_added = 0
if fully_connected_start:
start_connections = itertools.combinations(nodes[:m_0], 2)
else: # circle
start_connections = (
[(nodes[m_0-1], nodes[0])] +
[(nodes[i], nodes[i+1]) for i in range(m_0-1)]
)
for u, v in start_connections:
ba.addEdge(u, v)
edges_added += 1
for i, v in list(enumerate(nodes))[m_0:]:
num_new_edges = min(i, int((m-edges_added)/(n-i)))
to_connect = set()
while len(to_connect) < num_new_edges:
num_draws = num_new_edges - len(to_connect)
to_connect_draws = [
random.choice(ba.randomEdge())
for i in range(num_draws)
]
to_connect |= set(
u for u in to_connect_draws if not ba.hasEdge(v, u)
)
for u in to_connect:
ba.addEdge(u, v)
edges_added += num_new_edges
return ba
def get_commit_graph(repo, period='month'):
g = nk.Graph(weighted=True)
date_format = period_formatstring(period)
modularity = {}
nodes = {}
fp_commits = get_fp_chain(repo)
month = fp_commits[0].authored_datetime.strftime(date_format)
for parent_idx, commit in enumerate(fp_commits[1:]):
commit_month = commit.authored_datetime.strftime(date_format)
if commit_month > month:
community = nk.community.PLM(g) # PLP is ~5% faster but coarse
community.run()
partition = community.getPartition()
modularity[month] = (partition.numberOfSubsets(), len(nodes),
len(g.edges()))
month = commit_month
parent = fp_commits[parent_idx]
files = [] # files changed in this commit
for diff in commit.diff(parent):
fname = diff.a_path
if fname not in nodes:
nodes[fname] = g.addNode()
files.append(fname)
for i, file1 in enumerate(files[:-1]):
for file2 in files[i + 1:]:
g.increaseWeight(nodes[file1], nodes[file2], 1)
return g, modularity, nodes
def execute_with_networkit(file_name):
"""
Utilizzo le funzioni di networkit per verificare la correttezza degli algoritmi implementati.
Networkit fornisce lo stesso risultato degli algoritmi solamente nel caso in cui il grafo sia diretto (DIR=True)
poichè nella funzione addEdge di nk.Graph "It is not checked whether this edge already exists, thus it is possible
to create multi-edges.", il quale controllo invece viene effettuato nelle implementazioni realizzate,
presenti nel file Graph.py
"""
conn, ver = create_connections_from_file(file_name, networkit=True)
g = nk.Graph(n=max(ver) + 1, weighted=True, directed=True)
for tupla in conn:
g.addEdge(tupla[0], tupla[1], tupla[2])
dist = nk.distance.APSP(g)
dist.run()
matrix = dist.getDistances()
for riga in range(len(matrix)):
for col in range(len(matrix)):
if matrix[riga][col] > sys.maxsize / 2:
matrix[riga][
col] = sys.maxsize # per avere uguaglianza con Floyd-Warshall e Dijkstra
else:
matrix[riga][col] = int(matrix[riga][col])
mat = create_square_matrix(ver)
for i in range(len(ver)):
for j in range(len(ver)):
if i != j:
mat[i][j] = matrix[ver[i]][ver[j]]
return mat
def generateGraph(directed): G = nk.Graph(5, False, directed) G.addEdge(0, 1) G.addEdge(0, 2) G.addEdge(2, 1) G.addEdge(1, 3) G.addEdge(4, 2) return G
def make_graph_from_json(json_data):
G = nk.Graph()
for node in json_data:
for neighbor in json_data[node]:
G.addEdge(int(node), int(neighbor), addMissing=True)
return G
def testSubgraphFromNodes(self):
# Directed
G = nk.Graph(4, True, True)
G.addEdge(0, 1, 1.0)
G.addEdge(0, 2, 2.0)
G.addEdge(3, 1, 4.0)
G.addEdge(3, 2, 5.0)
G.addEdge(1, 2, 3.0)
res = G.subgraphFromNodes([0])
self.assertTrue(res.isWeighted())
self.assertTrue(res.isDirected())
self.assertEqual(res.numberOfNodes(), 1)
self.assertEqual(res.numberOfEdges(), 0)
res = G.subgraphFromNodes([0], True)
self.assertEqual(res.numberOfNodes(), 3)
self.assertEqual(res.numberOfEdges(), 2)
res = G.subgraphFromNodes([0, 1])
self.assertEqual(res.numberOfNodes(), 2)
self.assertEqual(res.numberOfEdges(), 1)
res = G.subgraphFromNodes([0, 1], True)
self.assertEqual(res.numberOfNodes(), 3)
self.assertEqual(res.numberOfEdges(), 3)
res = G.subgraphFromNodes([0, 1], True, True)
self.assertEqual(res.numberOfNodes(), 4)
self.assertEqual(res.numberOfEdges(), 4)
# Undirected
G = G.toUndirected()
res = G.subgraphFromNodes([0])
self.assertTrue(res.isWeighted())
self.assertFalse(res.isDirected())
self.assertEqual(res.numberOfNodes(), 1)
self.assertEqual(res.numberOfEdges(), 0)
res = G.subgraphFromNodes([0], True)
self.assertEqual(res.numberOfNodes(), 3)
self.assertEqual(res.numberOfEdges(), 2)
self.assertEqual(G.weight(0, 1), 1.0)
self.assertEqual(G.weight(0, 2), 2.0)
res = G.subgraphFromNodes([0, 1])
self.assertEqual(res.numberOfNodes(), 2)
self.assertEqual(res.numberOfEdges(), 1)
res = G.subgraphFromNodes([0, 1], True)
self.assertEqual(res.numberOfNodes(), 4)
self.assertEqual(res.numberOfEdges(), 4)
res = G.subgraphFromNodes(set([0, 1]), True)
self.assertEqual(res.numberOfNodes(), 4)
self.assertEqual(res.numberOfEdges(), 4)
def testNeighbors(self):
# Directed
G = nk.Graph(4, False, True)
G.addEdge(0, 1)
G.addEdge(0, 2)
G.addEdge(3, 1)
G.addEdge(3, 2)
G.addEdge(1, 2)
def getNeighbors(u):
neighbors = []
for v in G.iterNeighbors(u):
neighbors.append(v)
return sorted(neighbors)
def getInNeighbors(u):
inNeighbors = []
for v in G.iterInNeighbors(u):
inNeighbors.append(v)
return sorted(inNeighbors)
self.assertListEqual(getNeighbors(0), [1, 2])
self.assertListEqual(getNeighbors(1), [2])
self.assertListEqual(getNeighbors(2), [])
self.assertListEqual(getNeighbors(3), [1, 2])
self.assertListEqual(getInNeighbors(0), [])
self.assertListEqual(getInNeighbors(1), [0, 3])
self.assertListEqual(getInNeighbors(2), [0, 1, 3])
self.assertListEqual(getInNeighbors(3), [])
# Undirected
G = nk.Graph(4, False, False)
G.addEdge(0, 1)
G.addEdge(0, 2)
G.addEdge(3, 1)
G.addEdge(3, 2)
G.addEdge(1, 2)
self.assertEqual(getNeighbors(0), [1, 2])
self.assertEqual(getNeighbors(1), [0, 2, 3])
self.assertEqual(getNeighbors(2), [0, 1, 3])
self.assertEqual(getNeighbors(3), [1, 2])
def subgraph(g, s):
res = nk.Graph(len(s), weighted=g.isWeighted())
node_ids = OrderedDict(zip(s, range(len(s))))
for u in s:
for n in g.neighbors(u):
if u < n and n in s:
res.addEdge(node_ids[u], node_ids[n], g.weight(u, n))
return res
def make_graphs_into_one(G1, G2, num_edges_to_connect):
counter = 0
G = nk.Graph()
print(G.nodes())
print(G.edges())
G1_edges = list(G1.edges())
G2_edges = list(G2.edges())
G1_nodes = list(G1.nodes())
G2_nodes = list(G2.nodes())
size_of_G1 = len(G1_nodes)
G2_nodes = list(map(lambda x: size_of_G1 + x, G2_nodes))
for i in G1_nodes:
G.addNode()
for i in G2_nodes:
G.addNode()
#print(G.nodes())
print(len(G.nodes()))
for i, j in G1_edges:
G.addEdge(i, j)
print(G.edges())
#print(len(G.edges()))
for i, j in G2_edges:
u = size_of_G1 + i
v = size_of_G1 + j
G.addEdge(u, v)
print(G.edges())
print(len(G1.edges()))
print(len(G2.edges()))
print(len(G.edges()))
for i in range(num_edges_to_connect):
u = random.choice(G1_nodes)
v = random.choice(G2_nodes)
G.addEdge(u, v)
print(num_edges_to_connect)
print(len(G.edges()))
print(G.edges())
return G
def testGraphPickling(self):
G = nk.Graph(2)
G.addEdge(0, 1)
G.indexEdges()
pickledGraph = pickle.dumps(G)
G2 = pickle.loads(pickledGraph)
self.assertEqual(G.numberOfNodes(), G2.numberOfNodes())
self.assertEqual(G.numberOfEdges(), G2.numberOfEdges())
self.assertEqual(G.edgeId(0, 1), G2.edgeId(0, 1))
def getSmallGraph(self, weighted=False, directed=False):
G = nk.Graph(4, weighted, directed)
G.addEdge(0, 1, 1.0)
G.addEdge(0, 2, 2.0)
G.addEdge(3, 1, 4.0)
G.addEdge(3, 2, 5.0)
G.addEdge(1, 2, 3.0)
return G
def buildMesh(rows, cols):
G = nk.Graph(rows * cols, False, False)
for i in range(rows):
for j in range(cols):
if j < cols - 1:
G.addEdge(i * cols + j, i * cols + j + 1)
if i < rows - 1:
G.addEdge(i * cols + j, (i + 1) * cols + j)
return G
def plot_functions(g, outfile, recalculate=False):
x1, y1 = calculate_fractal_dimension(nk.Graph(g),
nk.centrality.DegreeCentrality,
recalculate)
x2, y2 = calculate_fractal_dimension(nk.Graph(g),
nk.centrality.Betweenness,
recalculate)
x3, y3 = calculate_fractal_dimension(nk.Graph(g), nk.centrality.Closeness,
recalculate)
x5, y5 = calculate_fractal_dimension(nk.Graph(g), random_ranking,
recalculate)
pylab.figure(1, dpi=500)
pylab.xlabel(r"Fraction of vertices removed ($\rho$)")
pylab.ylabel(r"Fractal dimension ($\sigma$)")
pylab.plot(x1, y1, "b-", alpha=0.6, linewidth=2.0)
pylab.plot(x2, y2, "g-", alpha=0.6, linewidth=2.0)
pylab.plot(x3, y3, "r-", alpha=0.6, linewidth=2.0)
pylab.plot(x5, y5, "k-", alpha=0.6, linewidth=2.0)
pylab.legend((r"Degree", "Betweenness", "Closeness", "Random"),
loc="upper right",
shadow=False)
pylab.savefig(outfile, format="png")
pylab.close(1)
# Generate csv file
import numpy as np
matrix = np.matrix([x1, y1, y2, y3, y5])
filename = outfile.rsplit(".", 1)[0] + ".csv"
header = ", degree, betweeness, closeness, random"
separator = ", "
np.savetxt(filename,
matrix.transpose(),
fmt="%s",
delimiter=separator,
header=header,
comments="")
def generateTwoComponents(directed, weighted):
G = nk.Graph(n, directed, weighted)
G.addEdge(0, 1)
G.addEdge(1, 2)
G.addEdge(2, 0)
G.addEdge(3, 4)
G.addEdge(4, 5)
G.addEdge(5, 3)
return G
def new_make_modular_network_ER(N, k_intra, k_inter, num_modules, SEED, alpha):
size_of_one_module = int(N / num_modules)
num_edges_to_connect = int(k_inter * N / 2)
counter = 0
G = nk.Graph()
nodes_list = []
size_G_nodes = 0
for mod_num in range(num_modules):
new_SEED = SEED * (mod_num + 2) + 1
print(size_of_one_module)
print(k_intra)
G_mod = make_ER_Graph(size_of_one_module, k_intra, new_SEED)
G_nodes = list(G_mod.nodes())
G_edges = list(G_mod.edges())
G_nodes = list(map(lambda x: x + size_G_nodes, G_nodes))
nodes_list.append(G_nodes)
for n in G_nodes:
G.addNode()
print(G_edges)
print(list(G.nodes()))
for (a, b) in G_edges:
u = size_G_nodes + a
v = size_G_nodes + b
G.addEdge(u, v)
size_G_nodes += len(G_nodes)
set_of_connected_nodes = set([])
for i in range(num_edges_to_connect):
(u, v) = get_random_u_v(nodes_list)
G.addEdge(u, v)
set_of_connected_nodes.add(u)
set_of_connected_nodes.add(v)
return (G, set_of_connected_nodes)
def iterative_rev_degree_order(depG):
G = nk.Graph(depG, weighted=True)
edges = sorted(G.edges(), key=lambda x: G.weightedDegree(x[0]) + G.weightedDegree(x[1]), reverse=True)
for u, v in edges:
try:
w = G.weight(u, v) / (G.weightedDegree(u) * G.weightedDegree(v))
except ZeroDivisionError as e:
continue
if w == 0:
G.removeEdge(u, v)
else:
G.setWeight(u, v, w=w)
return G
def testExtractLargestConnectedComponent(self): G = nk.Graph(10) for i in range(3): G.addEdge(i, i+1) for i in range(4, 9): G.addEdge(i, i+1) G1 = nk.components.ConnectedComponents.extractLargestConnectedComponent(G, True) self.assertEqual(G1.numberOfNodes(), 6) self.assertEqual(G1.numberOfEdges(), 5) G2 = nk.components.ConnectedComponents.extractLargestConnectedComponent(G, False) for i in range(G.numberOfNodes()): self.assertEqual(G2.hasNode(i), (4 <= i <= 9))
def make_graphs_into_one_multiple_graphs(G_list,num_edges_to_connect): counter = 0 G = nk.Graph() #print(G.nodes()) #print(G.edges()) nodes_list = [] size_G_nodes = 0 for G_mod in G_list: G_nodes = list(G_mod.nodes()) G_edges = list(G_mod.edges()) G_nodes = list(map(lambda x : x + size_G_nodes, G_nodes)) nodes_list.append(G_nodes) for n in G_nodes: G.addNode() print(G_edges) print(list(G.nodes())) for (a,b) in G_edges: u = size_G_nodes + a v = size_G_nodes + b G.addEdge(u,v) size_G_nodes += len(G_nodes) set_of_connected_nodes = set([]) for i in range(num_edges_to_connect): (u,v) = get_random_u_v(nodes_list) G.addEdge(u,v) set_of_connected_nodes.add(u) set_of_connected_nodes.add(v) return (G, set_of_connected_nodes)
def read_graph(fin):
n = int(fin.readline())
G = nk.Graph(n)
while True:
try:
line = fin.readline()
except:
break
line = line.split()
if len(line) == 0:
break
x = int(line[0][:-1])
arr = [int(y) for y in line[1:]]
for y in arr:
if not G.hasEdge(x, y):
G.addEdge(x, y, addMissing=True)
return G, n
def make_graphs_into_one_multiple_graphs_alpha(G_list, num_edges_to_connect,
alpha):
counter = 0
G = nk.Graph()
print(G.nodes())
print(G.edges())
nodes_list = []
alpha_nodes_list = []
size_G_nodes = 0
for i in G_list:
G_nodes = list(i.nodes())
G_edges = list(i.edges())
G_nodes = list(map(lambda x: x + size_G_nodes, G_nodes))
size_G_nodes += len(G_nodes)
nodes_list.append(G_nodes)
num_nodes_to_sample = len(G_nodes) * alpha
curr_alpha = random.sample(G_nodes, num_nodes_to_sample)
alpha_nodes_list.append(curr_alpha)
for n in G_nodes:
G.addNode()
for i, j in G_edges:
u = size_G_nodes + i
v = size_G_nodes + j
G.addEdge(u, v)
for i in range(num_edges_to_connect):
(u, v) = get_random_u_v(alpha_nodes_list)
G.addEdge(u, v)
return G
def build_networkit(edges, verbose=True, nnodes=None):
"""Builds a `networkit` graph from the input edges.
edges : array or list
The input graph edges as a list or array of two-element lists or
tuples.
Example: [(1,9), (2,3), (4,7), ...]
verbose : bool or int, optional, default: True
If True or 1, it produces lots of logging output.
**kwargs : dict
Additional keyword arguments for the `networkit.Graph`
function.
Returns
-------
G : `networkit` graph object
The output graph made from the input edges.
"""
if nnodes is None:
t0 = datetime.datetime.now()
unraveled = list(
chain.from_iterable(edges)) # TODO: np.concat is faster!
if not isinstance(unraveled[0], str) and not isinstance(
unraveled[1], str):
nnodes = max(
unraveled) + 1 # just enough nodes to construct the graph
else:
nnodes = len(unraveled) # length of ('a',5), ('f',2), ...
if verbose:
# Important: do not rely on this to cover all the isolated
# coords (as isolated nodes in the graph).
# That's why we used `np.arange` later to fill in the possible
# missing bits.
elapsed_seconds = round((datetime.datetime.now() - t0).seconds)
print(
f"It took {str(datetime.timedelta(seconds=elapsed_seconds))} hms to identify the number"
f"of nodes, i.e. `nnodes`={nnodes}.")
del unraveled
G = nk.Graph(nnodes, directed=False)
for edge in edges:
G.addEdge(*edge)
return G
def glove(depG, xmax=100, alpha=0.75):
G = nk.Graph(depG, weighted=True)
edges_list = depG.edges()
dico = dict()
tot = depG.totalEdgeWeight()
res = -1
for n1, n2 in edges_list:
w = depG.weight(n1, n2)
if (w > xmax):
res = 1
else:
res = (w / xmax) ** alpha
dico[(n1, n2)] = res
for n1, n2 in dico:
if dico[(n1, n2)] != 0:
G.setWeight(n1, n2, dico[(n1, n2)])
else:
G.removeEdge(n1, n2)
return G
def pmi(depG):
G = nk.Graph(depG, weighted=True)
edges_list = depG.edges()
dico = dict()
tot = depG.totalEdgeWeight()
for n1, n2 in edges_list:
w1 = depG.weightedDegree(n1)
w2 = depG.weightedDegree(n2)
w = depG.weight(n1, n2)
try:
pmi = log2((w * tot)/(w1 * w2))
except ZeroDivisionError as e:
pmi = 0
dico[(n1, n2)] = pmi
for n1, n2 in dico:
if dico[(n1, n2)] != 0:
G.setWeight(n1, n2, dico[(n1, n2)])
else:
G.removeEdge(n1, n2)
return G
def get_subgraph(self, mask_array):
masked_num = mask_array.sum()
new_graph = networkit.Graph(n=masked_num, directed=True, weighted=True)
# Map old (full) node ids to new (subgraph) node ids
full_to_sub = {}
for sub, full in enumerate(np.flatnonzero(mask_array)):
full_to_sub[full] = sub
# Insert edges
def insert_new_edges(from_node,to_node,edgeweight,edgeid):
new_from_node = full_to_sub.get(from_node,-99)
new_to_node = full_to_sub.get(to_node, -99)
if -99 in (new_from_node, new_to_node):
return
new_graph.addEdge(new_from_node,new_to_node,edgeweight)
for node in full_to_sub.keys():
self.graph.forEdgesOf(node, insert_new_edges)
return new_graph
def test_DegreeCentrality(self): g = nk.Graph(8, False, False) g.addEdge(0, 2) g.addEdge(0, 5) g.addEdge(1, 2) g.addEdge(2, 3) g.addEdge(2, 2) g.addEdge(2, 4) g.addEdge(3, 5) g.addEdge(4, 5) g.addEdge(5, 5) g.addEdge(5, 6) g.addEdge(5, 7) g.addEdge(7, 7) expected_result = [2.0, 1.0, 4.0, 2.0, 2.0, 5.0, 1.0, 1.0] dc = nk.centrality.DegreeCentrality(g).run().scores() self.assertListEqual(expected_result, dc)
def standard(depG):
G = nk.Graph(depG, weighted=True)
edges_list = depG.edges()
dico = dict()
tot = depG.totalEdgeWeight()
for n1, n2 in edges_list:
w1 = depG.weightedDegree(n1)
w2 = depG.weightedDegree(n2)
w = depG.weight(n1, n2)
try:
res = w / (w1 * w2)
except ZeroDivisionError as e:
# print(w1, w2, w)
res = 0
dico[(n1, n2)] = res
for n1, n2 in dico:
if dico[(n1, n2)] != 0:
G.setWeight(n1, n2, dico[(n1, n2)])
else:
G.removeEdge(n1, n2)
return G