def test_singleton(self, graph):
G = graph()
G.add_node("x")
assert nx.spectral_ordering(G) == ["x"]
G.add_edge("x", "x", weight=33)
G.add_edge("x", "x", weight=33)
assert nx.spectral_ordering(G) == ["x"]
def test_singleton(self):
for graph in (nx.Graph, nx.DiGraph, nx.MultiGraph, nx.MultiDiGraph):
G = graph()
G.add_node('x')
assert_equal(nx.spectral_ordering(G), ['x'])
G.add_edge('x', 'x', weight=33)
G.add_edge('x', 'x', weight=33)
assert_equal(nx.spectral_ordering(G), ['x'])
def test_singleton(self):
for graph in (nx.Graph, nx.DiGraph, nx.MultiGraph, nx.MultiDiGraph):
G = graph()
G.add_node("x")
assert nx.spectral_ordering(G) == ["x"]
G.add_edge("x", "x", weight=33)
G.add_edge("x", "x", weight=33)
assert nx.spectral_ordering(G) == ["x"]
def test_three_nodes(self):
G = nx.Graph()
G.add_weighted_edges_from([(1, 2, 1), (1, 3, 2), (2, 3, 1)],
weight='spam')
for method in self._methods:
order = nx.spectral_ordering(G, weight='spam', method=method)
assert_equal(set(order), set(G))
ok_(set([1, 3]) in (set(order[:-1]), set(order[1:])))
G = nx.MultiDiGraph()
G.add_weighted_edges_from([(1, 2, 1), (1, 3, 2), (2, 3, 1), (2, 3, 2)])
for method in self._methods:
order = nx.spectral_ordering(G, method=method)
assert_equal(set(order), set(G))
ok_(set([2, 3]) in (set(order[:-1]), set(order[1:])))
def test_three_nodes(self):
G = nx.Graph()
G.add_weighted_edges_from([(1, 2, 1), (1, 3, 2), (2, 3, 1)],
weight="spam")
for method in self._methods:
order = nx.spectral_ordering(G, weight="spam", method=method)
assert set(order) == set(G)
assert {1, 3} in (set(order[:-1]), set(order[1:]))
G = nx.MultiDiGraph()
G.add_weighted_edges_from([(1, 2, 1), (1, 3, 2), (2, 3, 1), (2, 3, 2)])
for method in self._methods:
order = nx.spectral_ordering(G, method=method)
assert set(order) == set(G)
assert {2, 3} in (set(order[:-1]), set(order[1:]))
def spectral_populate_subset(G, root, subset_size, gains, threshold):
if G.number_of_nodes() <= subset_size:
return list(G.nodes())
ordering = nx.spectral_ordering(G)
logging.info("Ordering: {}, root: {}, threshold: {}".format(
ordering, root, threshold))
left_it = ordering.index(root) - 1
right_it = left_it + 2
res_subset = {root}
while len(res_subset) < subset_size:
# move two pointers and add encountered vertices if the gain is larger than threshold
try:
left_cand = ordering[left_it]
if gains[left_cand] >= threshold:
res_subset.add(left_cand)
logging.info("Adding ordering[{}]={} with gain {}".format(
left_it, left_cand, gains[left_cand]))
left_it -= 1
except IndexError:
pass
try:
right_cand = ordering[right_it]
if gains[right_cand] >= threshold:
res_subset.add(right_cand)
logging.info("Adding ordering[{}]={} with gain {}".format(
right_it, right_cand, gains[right_cand]))
right_it += 1
except IndexError:
pass
return list(res_subset)
def test_three_nodes_multigraph(self, method):
pytest.importorskip("scipy")
G = nx.MultiDiGraph()
G.add_weighted_edges_from([(1, 2, 1), (1, 3, 2), (2, 3, 1), (2, 3, 2)])
order = nx.spectral_ordering(G, method=method)
assert set(order) == set(G)
assert {2, 3} in (set(order[:-1]), set(order[1:]))
def test_cycle(self):
path = list(range(10))
G = nx.Graph()
nx.add_path(G, path, weight=5)
G.add_edge(path[-1], path[0], weight=1)
A = nx.laplacian_matrix(G).todense()
for normalized in (False, True):
for method in methods:
try:
order = nx.spectral_ordering(G,
normalized=normalized,
method=method)
except nx.NetworkXError as e:
if e.args not in (
("Cholesky solver unavailable.", ),
("LU solver unavailable.", ),
):
raise
else:
if not normalized:
assert order in [
[1, 2, 0, 3, 4, 5, 6, 9, 7, 8],
[8, 7, 9, 6, 5, 4, 3, 0, 2, 1],
]
else:
assert order in [
[1, 2, 3, 0, 4, 5, 9, 6, 7, 8],
[8, 7, 6, 9, 5, 4, 0, 3, 2, 1],
]
def test_seed_argument(self, method):
path = list(range(10))
np.random.shuffle(path)
G = nx.Graph()
nx.add_path(G, path)
order = nx.spectral_ordering(G, method=method, seed=1)
assert order in [path, list(reversed(path))]
def test_path(self):
path = list(range(10))
shuffle(path)
G = nx.Graph()
G.add_path(path)
for method in self._methods:
order = nx.spectral_ordering(G, method=method)
ok_(order in [path, list(reversed(path))])
def test_path(self, method):
pytest.importorskip("scipy")
path = list(range(10))
np.random.shuffle(path)
G = nx.Graph()
nx.add_path(G, path)
order = nx.spectral_ordering(G, method=method)
assert order in [path, list(reversed(path))]
def test_path(self):
path = list(range(10))
shuffle(path)
G = nx.Graph()
G.add_path(path)
for method in self._methods:
order = nx.spectral_ordering(G, method=method)
ok_(order in [path, list(reversed(path))])
def test_cycle(self, normalized, expected_order, method):
pytest.importorskip("scipy")
path = list(range(10))
G = nx.Graph()
nx.add_path(G, path, weight=5)
G.add_edge(path[-1], path[0], weight=1)
A = nx.laplacian_matrix(G).todense()
order = nx.spectral_ordering(G, normalized=normalized, method=method)
assert order in expected_order
def test_seed_argument(self, method):
# based on setup_class numpy is installed if we get here
from numpy.random import shuffle
path = list(range(10))
shuffle(path)
G = nx.Graph()
nx.add_path(G, path)
order = nx.spectral_ordering(G, method=method, seed=1)
assert order in [path, list(reversed(path))]
def test_path(self):
# based on setupClass numpy is installed if we get here
from numpy.random import shuffle
path = list(range(10))
shuffle(path)
G = nx.Graph()
nx.add_path(G, path)
for method in self._methods:
order = nx.spectral_ordering(G, method=method)
ok_(order in [path, list(reversed(path))])
def test_disconnected(self):
G = nx.Graph()
nx.add_path(G, range(0, 10, 2))
nx.add_path(G, range(1, 10, 2))
for method in self._methods:
order = nx.spectral_ordering(G, method=method)
assert_equal(set(order), set(G))
seqs = [list(range(0, 10, 2)), list(range(8, -1, -2)),
list(range(1, 10, 2)), list(range(9, -1, -2))]
ok_(order[:5] in seqs)
ok_(order[5:] in seqs)
def test_disconnected(self, method):
G = nx.Graph()
nx.add_path(G, range(0, 10, 2))
nx.add_path(G, range(1, 10, 2))
order = nx.spectral_ordering(G, method=method)
assert set(order) == set(G)
seqs = [
list(range(0, 10, 2)),
list(range(8, -1, -2)),
list(range(1, 10, 2)),
list(range(9, -1, -2)),
]
assert order[:5] in seqs
assert order[5:] in seqs
def test_cycle(self, normalized, expected_order, method):
path = list(range(10))
G = nx.Graph()
nx.add_path(G, path, weight=5)
G.add_edge(path[-1], path[0], weight=1)
A = nx.laplacian_matrix(G).todense()
try:
order = nx.spectral_ordering(G, normalized=normalized, method=method)
except nx.NetworkXError as e:
if e.args not in (
("Cholesky solver unavailable.",),
("LU solver unavailable.",),
):
raise
else:
assert order in expected_order
def layout_two_column(H, spacing=2):
"""
Two column (bipartite) layout algorithm.
This algorithm first converts the hypergraph into a bipartite graph and
then computes connected components. Disonneccted components are handled
independently and then stacked together.
Within a connected component, the spectral ordering of the bipartite graph
provides a quick and dirty ordering that minimizes edge crossings in the
diagram.
Parameters
----------
H: Hypergraph
the entity to be drawn
spacing: float
amount of whitespace between disconnected components
"""
offset = 0
pos = {}
def stack(vertices, x, height):
for i, v in enumerate(vertices):
pos[v] = (x, i + offset + (height - len(vertices)) / 2)
G = H.bipartite()
for ci in nx.connected_components(G):
Gi = G.subgraph(ci)
key = {v: i for i, v in enumerate(nx.spectral_ordering(Gi))}.get
ci_vertices, ci_edges = [
sorted([v for v, d in Gi.nodes(data=True) if d["bipartite"] == j],
key=key) for j in [0, 1]
]
height = max(len(ci_vertices), len(ci_edges))
stack(ci_vertices, 0, height)
stack(ci_edges, 1, height)
offset += height + spacing
return pos
def main2():
""" spectral same part"""
method = 'pyomo'
if method == 'dwave':
solver = start_sapi()
embedding = get_native_embedding(solver)
num_reads = 1000
annealing_time = 200
#seed = random.randint(1,10000)
#seed = 8834
#print seed
random.seed(seed)
filename = sys.argv[1]
graph = data_to_graph(filename)
#print '%i nodes, %i edges' %(nx.number_of_nodes(graph), nx.number_of_edges(graph))
mod_matrix = nx.modularity_matrix(graph, nodelist=sorted(graph.nodes()))
nnodes = nx.number_of_nodes(graph)
hardware_size = 25
ptn = [1 - 2 * random.randint(0, 1) for _ in range(nnodes)]
#init_ptn = [1 for _ in range(nnodes)]
#init_ptn = [np.sign(i) for i in nx.fiedler_vector(graph).tolist()]
mod = compute_modularity(graph, mod_matrix, ptn)
#print 'init modularity:', mod, 0.25*mod/nx.number_of_edges(graph)
ptn_variables = {}
for node in sorted(graph.nodes()):
ptn_variables[node] = ptn[node]
sp_order = nx.spectral_ordering(graph)
for mynode in sorted(graph.nodes()):
free_nodes = spectral_neigh_same_part(mynode, graph, mod_matrix, ptn,
hardware_size, sp_order)
for node in free_nodes:
ptn_variables[node] = 'free'
if method == 'dwave':
new_ptn = sapi_refine_modularity(graph, solver, hardware_size,
ptn_variables, num_reads,
annealing_time, embedding)
else:
new_ptn = pyomo_refine(graph, ptn_variables)
for node in free_nodes:
ptn_variables[node] = new_ptn[node]
mod = compute_modularity(graph, mod_matrix, new_ptn)
def _basic_partitioning(G, n1, n2):
"""
Genera le 2 classi composte da n1 e n2 nodi a partire da G.
La divisione viene effettuata con l'algoritmo spettrale
Da usare all'interno di spectral_partitioning(G, class_nodes)
:param G: grafo semplice connesso
:param n1: nodi della prima classe
:param n2: nodi della seconda classe
:return: un sottografo, vista di G. La struttura del sottografo non può essere modificata
"""
# Lista di nodi ordinati secondo il vettore di Fiedler
ordered_nodes = nx.spectral_ordering(
G, method="lanczos") # Torna una list non un nunmpy array
group_test_1 = set(ordered_nodes[:n1]) # primi n1
group_test_2 = set(ordered_nodes[:n2]) # primi n2
cut_size_1 = nx.cut_size(G, group_test_1)
cut_size_2 = nx.cut_size(G, group_test_2)
# Scelgo la componente che dividerà il grafo in base al peso del suo insieme di taglio
if cut_size_1 < cut_size_2:
final_group = group_test_1
remaining_group = set(ordered_nodes[n1:])
G_1 = G.subgraph(final_group)
G_2 = G.subgraph(remaining_group)
else:
final_group = group_test_2 # n2
remaining_group = set(ordered_nodes[n2:]) #n1
G_1 = G.subgraph(remaining_group)
G_2 = G.subgraph(final_group)
# Fuori dall'if non va bene per il caso di spectral_partitioning([9,(5, 4)]
# G_1 = G.subgraph(final_group)
# G_2 = G.subgraph(remaining_group)
# G_1 avrà sempre big_class1_nodes e G_2 avrà sempre big_class2_nodes
# print('basic part. primo gruppo ha nodi: ', nx.number_of_nodes(G_1))
# print('basic part. secondo gruppo ha nodi: ', nx.number_of_nodes(G_2))
yield from (G_1, G_2)
def reorder(data,
absolute=False,
return_corr=False,
approx=False,
threshold=0,
split=True):
if data.shape[1] > 6:
approx = True
modified_corr = corr = pd.DataFrame(squareform(
[pearsonr(data[r], data[c])[0] for r, c in combinations(data, 2)]),
index=list(data),
columns=list(data)).fillna(0)
if absolute:
modified_corr = modified_corr.abs()
modified_corr = modified_corr * (modified_corr >= threshold)
if approx:
G = nx.from_pandas_adjacency(modified_corr)
data = data[nx.spectral_ordering(G)]
else:
values = modified_corr.values
split = int(split == True)
def objective(ii):
jj = np.roll(ii, 1)
return values[ii[split:], jj[split:]].sum()
best = max(map(np.array, permutations(range(len(values)))),
key=objective)
data = data[data.columns[best]]
if return_corr:
order = list(data)
return data, corr.loc[order, order]
return data
def test_cycle(self):
path = list(range(10))
G = nx.Graph()
nx.add_path(G, path, weight=5)
G.add_edge(path[-1], path[0], weight=1)
A = nx.laplacian_matrix(G).todense()
for normalized in (False, True):
for method in methods:
try:
order = nx.spectral_ordering(G, normalized=normalized,
method=method)
except nx.NetworkXError as e:
if e.args not in (('Cholesky solver unavailable.',),
('LU solver unavailable.',)):
raise
else:
if not normalized:
ok_(order in [[1, 2, 0, 3, 4, 5, 6, 9, 7, 8],
[8, 7, 9, 6, 5, 4, 3, 0, 2, 1]])
else:
ok_(order in [[1, 2, 3, 0, 4, 5, 9, 6, 7, 8],
[8, 7, 6, 9, 5, 4, 0, 3, 2, 1]])
def get_feature_order(X, eps=.25):
A = squareform(pdist(X.T, metric=lambda x, y: pearsonr(x, y)[0]))
A[A < eps] = 0
G = nx.relabel_nodes(nx.from_numpy_array(A), {i:s for i,s in enumerate(X.columns)})
return nx.spectral_ordering(G)
def test_spectral_ordering_tracemin_chol():
"""Test that "tracemin_chol" raises an exception."""
pytest.importorskip("scipy")
G = nx.barbell_graph(5, 4)
with pytest.raises(nx.NetworkXError):
nx.spectral_ordering(G, method="tracemin_chol")
def main():
#method = 'pyomo'
method = 'dwave'
free_node_method = 'top_gain'
#free_node_method = 'spectral'
#free_node_method = 'random'
#free_node_method = 'boundary_spectral'
#free_node_method = 'tg_sp_same_part'
if method == 'dwave':
solver = start_sapi()
embedding = get_native_embedding(solver)
num_reads = 1000
annealing_time = 200
filename = sys.argv[1]
graph = data_to_graph(filename)
#print graph.nodes()
print('%i nodes, %i edges' %
(nx.number_of_nodes(graph), nx.number_of_edges(graph)))
if nx.number_of_nodes(graph) > 600:
exit()
mod_matrix = nx.modularity_matrix(graph, nodelist=sorted(graph.nodes()))
nnodes = nx.number_of_nodes(graph)
hardware_size = 25
#init_ptn = [1 - 2*random.randint(0,1) for _ in range(nnodes)]
seeds = [
1070, 8173, 3509, 8887, 1314, 4506, 5219, 3765, 1420, 7778, 3734, 6509,
1266, 5063, 6496, 4622, 7018, 6052, 8932, 8215, 1254, 400, 3260, 5999,
1331, 8073, 7357, 2928, 7208, 3874
]
niters = []
mod_values = []
for __, seed in enumerate(seeds):
#print('exp %i' %__)
#seed = 0
random.seed(seed)
np.random.seed(seed)
init_ptn = [
1 - 2 * x for x in list(
np.random.randint(2, size=(graph.number_of_nodes(), )))
]
#print init_ptn
mod = compute_modularity(graph, mod_matrix, init_ptn)
#print('init modularity:', mod, 0.25*mod/nx.number_of_edges(graph))
ptn_variables = {}
for node in sorted(graph.nodes()):
ptn_variables[node] = init_ptn[node]
free_nodes = get_random_nodes(graph, hardware_size)
free_set = set(free_nodes)
sp_order = nx.spectral_ordering(graph)
#sp_order = list(reverse_cuthill_mckee_ordering(graph))
#print(sp_order)
free_nodes = get_free_nodes(graph,
mod_matrix,
init_ptn,
hardware_size,
sp_order,
method=free_node_method)
not_converge = True
myiter = 0
nconv = 5
best_soln = -float('inf')
while not_converge:
myiter += 1
#print len(free_nodes)
for node in free_nodes:
ptn_variables[node] = 'free'
if method == 'dwave':
new_ptn = sapi_refine_modularity(graph, solver, hardware_size,
ptn_variables, num_reads,
annealing_time, embedding)
else:
new_ptn = pyomo_refine(graph, ptn_variables)
for node in free_nodes:
ptn_variables[node] = new_ptn[node]
mod = compute_modularity(graph, mod_matrix, new_ptn)
#print(myiter, 'refine modularity:', mod, 0.25*mod/nx.number_of_edges(graph))
free_nodes = get_free_nodes(graph,
mod_matrix,
new_ptn,
hardware_size,
sp_order,
method=free_node_method)
current_free_set = set(free_nodes)
if mod > best_soln:
best_soln = mod
best_it = myiter
if free_set == current_free_set:
not_converge = False
elif myiter - best_it >= nconv:
not_converge = False
free_set = current_free_set
niters.append(myiter)
mod_values.append(0.25 * mod / nx.number_of_edges(graph))
#print(seed, myiter, 0.25*mod/nx.number_of_edges(graph))
best = max(mod_values)
worst = min(mod_values)
av = np.mean(mod_values)
std = np.std(mod_values)
b_it = min(niters)
w_it = max(niters)
av_it = np.mean(niters)
std_it = np.std(niters)
#print(seeds)
out = [worst, av, best, std, b_it, av_it, w_it, std_it]
out = '& '.join([str(round(i, 4)) for i in out])
print(out)
print('-------------------\n')
'''
sumfile.write(dens)
# analyze the network
hist = nx.degree_histogram(fb_net)
plt.figure(figsize=(10, 10))
plt.plot(hist, linestyle=':')
plt.title('Degree Historam')
plt.savefig('fbNet_Degree.png')
plt.close()
print('Degree Historam finished')
lap_spec = nx.laplacian_spectrum(fb_net)
plt.plot(lap_spec)
plt.title('Eigenvalues of the Laplacian')
plt.savefig('fbNet_LapSpec.png')
plt.close()
print('Eigenvalues of the Laplacian')
adj_spec = nx.adjacency_spectrum(fb_net)
plt.plot(adj_spec)
plt.title('Eigenvalues of the Adjaceny')
plt.savefig('fbNet_AdjSpec.png')
plt.close()
print('Eigenvalues of the Adjaceny')
spec_ordering = nx.spectral_ordering(fb_net)
plt.plot(spec_ordering)
plt.title('Spectral Ordering')
plt.savefig('fbNet_SpecOrder.png')
plt.close()
print('Spectral Ordering')
def setup(g, num_players, num_seeds):
return nx.spectral_ordering(g)
