def barabasi_albert(n,
n_init,
k=1,
node_names=None,
directed=False,
temporal=False):
"""
"""
if node_names is None:
node_names = [str(x) for x in range(n)]
assert len(
node_names
) >= n, 'Error: Number of node names not matching degree sequence length'
if not temporal:
network = Network(directed=directed)
else:
network = TemporalNetwork()
endpoints = []
time = 0
# initial network
for i in range(n_init):
for j in range(n_init):
if i < j:
if not temporal:
network.add_edge(str(node_names[i]), str(node_names[j]))
else:
network.add_edge(str(node_names[i]),
str(node_names[j]),
time,
directed=directed)
endpoints.append(str(node_names[i]))
endpoints.append(str(node_names[j]))
for i in range(n_init, n):
time += 1
# TODO: for k>1 we can choose different stubs of the same node in one step!
targets = _np.random.choice(endpoints, size=k, replace=False)
for t in targets:
if not temporal:
network.add_edge(str(node_names[i]), t)
else:
network.add_edge(str(node_names[i]),
t,
time,
directed=directed)
endpoints.append(str(node_names[i]))
endpoints.append(t)
return network
def erdoes_renyi_gnm(n,
m,
node_names=None,
self_loops=True,
directed=False,
temporal=False):
"""
"""
if node_names is None:
node_names = [str(x) for x in range(n)]
assert len(
node_names
) >= n, 'Error: Number of node names not matching degree sequence length'
if not temporal:
network = Network(directed=directed)
else:
network = TemporalNetwork()
# generate nodes
if not temporal:
for i in range(n):
network.add_node(str(node_names[i]))
time = -1
m_current = 0
edges = defaultdict(lambda: False)
# add edges
while m_current < m:
edge = _np.random.choice(n, size=2, replace=self_loops)
edge = [node_names[edge[0]], node_names[edge[1]]]
if not edges[(edge[0], edge[1])]:
edges[(edge[0], edge[1])] = True
if not directed:
edges[(edge[1], edge[0])] = True
if not temporal:
m_current += 1
network.add_edge(edge[0], edge[1])
else:
time += 1
m_current += 1
network.add_edge(edge[0], edge[1], time, directed=directed)
return network
def erdoes_renyi_gnp(n,
p,
node_names=None,
self_loops=True,
directed=False,
temporal=False):
"""
"""
if node_names is None:
node_names = [str(x) for x in range(n)]
assert len(
node_names
) >= n, 'Error: Number of node names not matching degree sequence length'
if not temporal:
network = Network(directed=directed)
else:
network = TemporalNetwork()
# make sure that isolated nodes exist
if not temporal:
for i in range(n):
network.add_node(str(node_names[i]))
time = -1
# add edges
for i in range(n):
for j in range(i + 1):
if i != j or self_loops:
if _np.random.rand() <= p:
if not temporal:
network.add_edge(node_names[i], node_names[j])
else:
time += 1
network.add_edge(node_names[i],
node_names[j],
time,
directed=directed)
return network