def __init__(self,
graph,
merges,
membership=None,
modularity=None,
params={}):
"""Creates a dendrogram object for a given graph.
@param graph: the graph that will be associated to the clustering
@param merges: the merges performed given in matrix form.
@param membership: the membership list. The length of the list must
be equal to the number of vertices in the graph. If C{None}, the
dendrogram will be cut at the level where the modularity is maximized
and the membership list will represent this state.
@param modularity: the modularity score of the clustering on each
level of the dendrogram starting from the fully decomposed state.
If C{None}, it will be calculated.
@param params: additional parameters to be stored in this object.
"""
if modularity is None:
# TODO: this is a fairly simple way to calculate the modularity
ms = range(graph.vcount())
communities = range(graph.vcount())
modularity = []
n = graph.vcount()
for step in xrange(min(n - 1, len(merges))):
ms = community_to_membership(merges, graph.vcount(), step)
modularity.append(graph.modularity(ms))
if membership is None:
maxmod = max(modularity)
maxidx = modularity.index(maxmod)
membership = community_to_membership(merges, graph.vcount(),
maxidx)
recoding, n = {}, 0
for idx, m in enumerate(membership):
try:
membership[idx] = recoding[m]
except KeyError:
recoding[m], membership[idx] = n, n
n += 1
else:
maxmod = None
Dendrogram.__init__(self, merges)
VertexClustering.__init__(self, graph, membership, maxmod, params)
def __init__(self, graph, merges, membership = None, modularity = None, params = {}):
"""Creates a dendrogram object for a given graph.
@param graph: the graph that will be associated to the clustering
@param merges: the merges performed given in matrix form.
@param membership: the membership list. The length of the list must
be equal to the number of vertices in the graph. If C{None}, the
dendrogram will be cut at the level where the modularity is maximized
and the membership list will represent this state.
@param modularity: the modularity score of the clustering on each
level of the dendrogram starting from the fully decomposed state.
If C{None}, it will be calculated.
@param params: additional parameters to be stored in this object.
"""
if modularity is None:
# TODO: this is a fairly simple way to calculate the modularity
ms = range(graph.vcount())
communities = range(graph.vcount())
modularity = []
n = graph.vcount()
for step in xrange(min(n-1, len(merges))):
ms = community_to_membership(merges, graph.vcount(), step)
modularity.append(graph.modularity(ms))
if membership is None:
maxmod = max(modularity)
maxidx = modularity.index(maxmod)
membership = community_to_membership(merges, graph.vcount(), maxidx)
recoding, n = {}, 0
for idx, m in enumerate(membership):
try:
membership[idx] = recoding[m]
except KeyError:
recoding[m], membership[idx] = n, n
n += 1
else:
maxmod = None
Dendrogram.__init__(self, merges)
VertexClustering.__init__(self, graph, membership, maxmod, params)
def cut(self, n):
"""Cuts the dendrogram at a given level.
@param n: the desired number of clusters. Merges are replayed from the
beginning until the membership vector has exactly M{n} distinct elements
or until there are no more recorded merges, whichever happens first.
@return: the membership vector
"""
num_elts = self._graph.vcount()
membership = community_to_membership(self._merges, num_elts, num_elts-n)
idgen = UniqueIdGenerator()
self._membership = [idgen[m] for m in membership]
self._len = max(self._membership) + 1
return self._membership[:]
def cut(self, n):
"""Cuts the dendrogram at a given level.
@param n: the desired number of clusters. Merges are replayed from the
beginning until the membership vector has exactly M{n} distinct elements
or until there are no more recorded merges, whichever happens first.
@return: the membership vector
"""
num_elts = self._graph.vcount()
membership = community_to_membership(self._merges, num_elts,
num_elts - n)
idgen = UniqueIdGenerator()
self._membership = [idgen[m] for m in membership]
self._len = max(self._membership) + 1
return self._membership[:]
def as_clustering(self, n=None):
"""Cuts the dendrogram at the given level and returns a corresponding
L{VertexClustering} object.
@param n: the desired number of clusters. Merges are replayed from the
beginning until the membership vector has exactly M{n} distinct elements
or until there are no more recorded merges, whichever happens first.
If C{None}, the current membership vector will be used.
@return: a new L{VertexClustering} object.
"""
if n is not None:
num_elts = self._graph.vcount()
membership = community_to_membership(self._merges, num_elts, num_elts-n)
idgen = UniqueIdGenerator()
membership = [idgen[m] for m in membership]
else:
membership = self.membership
return VertexClustering(self._graph, membership)
def as_clustering(self, n=None):
"""Cuts the dendrogram at the given level and returns a corresponding
L{VertexClustering} object.
@param n: the desired number of clusters. Merges are replayed from the
beginning until the membership vector has exactly M{n} distinct elements
or until there are no more recorded merges, whichever happens first.
If C{None}, the current membership vector will be used.
@return: a new L{VertexClustering} object.
"""
if n is not None:
num_elts = self._graph.vcount()
membership = community_to_membership(self._merges, num_elts,
num_elts - n)
idgen = UniqueIdGenerator()
membership = [idgen[m] for m in membership]
else:
membership = self.membership
return VertexClustering(self._graph, membership)
def comm_detection(g, algorithm, weights_input):
if algorithm == 1:
# (1)社区发现，newman快速算法，VertexDendrogram
comm = list(g.community_fastgreedy(weights=weights_input).as_clustering())
comm.sort(key=lambda i: len(i), reverse=True)
num = len(comm)
elif algorithm == 2:
# (2)社区发现，louvain算法，VertexClustering
comm = list(g.community_multilevel(weights=weights_input))
comm.sort(key=lambda i: len(i), reverse=True)
num = len(comm)
elif algorithm == 3:
# (3)社区发现，leading_eigenvector算法，VertexClustering
comm = list(g.community_leading_eigenvector(weights=weights_input))
comm.sort(key=lambda i: len(i), reverse=True)
num = len(comm)
elif algorithm == 4:
# (4)社区发现，label_propagation算法，VertexClustering
comm = list(g.community_label_propagation(weights=weights_input, initial=None, fixed=None))
comm.sort(key=lambda i: len(i), reverse=True)
num = len(comm)
elif algorithm == 5:
# (5)社区发现，walktrap算法，VertexDendrogram
comm = list(g.community_walktrap(weights=weights_input, steps=4).as_clustering())
comm.sort(key=lambda i: len(i), reverse=True)
num = len(comm)
elif algorithm == 6:
# (6)社区发现，GN算法，VertexDendrogram(时间久，不推荐大网络)
se = g.community_edge_betweenness(clusters=None, directed=False, weights=weights_input)
n = se._graph.vcount()
max_q, optimal_count = 0, 1
for step in range(min(n - 1, len(se._merges))):
membs = ig.community_to_membership(se._merges, n, step)
q = se._graph.modularity(membs, **se._modularity_params)
if q > max_q:
optimal_count = n - step
max_q = q
se._optimal_count = optimal_count
comm = list(se.as_clustering())
comm.sort(key=lambda i: len(i), reverse=True)
num = len(comm)
elif algorithm == 7:
# (7)社区发现，spinglass算法，VertexClustering(时间久，不推荐大网络)
clusters = g.clusters()
giant = clusters.giant()
comm = list(giant.community_spinglass())
comm.sort(key=lambda i: len(i), reverse=True)
num = len(comm)
elif algorithm == 8:
# (8)社区发现，infomap算法，VertexClustering
# 本算法需要给定簇团划分数量(trials=10)，初始值为10
comm = list(g.community_infomap(edge_weights=weights_input, vertex_weights=None, trials=10))
comm.sort(key=lambda i: len(i), reverse=True)
num = len(comm)
else:
print('算法指定错误')
return comm, num