def get_bbn_potential(self, node):
"""
Gets the potential associated with the specified BBN node.
:param node: BBN node.
:return: Potential.
"""
clique = node.metadata['parent.clique']
return PotentialUtil.normalize(
PotentialUtil.marginalize_for(self, clique, [node]))
def start(self):
"""
Starts the evidence distribution.
"""
self.start_clique.mark()
for sep_set_id in self.join_tree.get_neighbors(self.start_clique.id):
sep_set = self.join_tree.get_node(sep_set_id)
for clique_id in self.join_tree.get_neighbors(sep_set_id):
y = self.join_tree.get_node(clique_id)
if not y.is_marked():
PotentialUtil.pass_single_message(self.join_tree,
self.start_clique,
sep_set, y)
self.__walk__(self.start_clique, sep_set, y)
def start(self):
"""
Starts the evidence distribution.
"""
self.start_clique.mark()
sepsets, cliques = self.__get_neighboring_cliques__(
self.join_tree, self.start_clique)
for clique in cliques:
clique[1].mark()
for s, c in zip(sepsets, cliques):
PotentialUtil.pass_single_message(self.join_tree,
self.start_clique, s[1], c[1])
self.__walk__(self.start_clique, s[1], c[1])
def __walk__(self, x, s, y):
"""
Walks away from the specified x clique.
:param x: Clique.
:param s: Separation-set.
:param y: Clique.
"""
y.mark()
for sep_set_id in self.join_tree.get_neighbors(y.id):
sep_set = self.join_tree.get_node(sep_set_id)
for clique_id in self.join_tree.get_neighbors(sep_set_id):
clique = self.join_tree.get_node(clique_id)
if not clique.is_marked():
self.__walk__(y, sep_set, clique)
PotentialUtil.pass_single_message(self.join_tree, y, s, x)
def init(bbn):
"""
Initializes the BBN potentials.
:param bbn: BBN graph.
"""
for node in bbn.get_nodes():
parents = [bbn.get_node(parent_id) for parent_id in bbn.get_parents_ordered(node.id)]
potential = PotentialUtil.get_potential(node, parents)
node.potential = potential
def reinit(jt):
"""
Reinitialize potentials of BBN nodes in join tree.
:param jt: Join tree.
:return: None.
"""
for node, parents in jt.get_bbn_node_and_parents().items():
potential = PotentialUtil.get_potential(node, parents)
node.potential = potential
def __walk__(self, x, s, y):
"""
Walks away from the specified node y.
:param x: Clique.
:param s: Separation-set.
:param y: Clique.
"""
sepsets, cliques = self.__get_neighboring_cliques__(self.join_tree, y)
s_arr = []
c_arr = []
for sep, cli in zip(sepsets, cliques):
if not cli[1].is_marked():
cli[1].mark()
s_arr.append(sep)
c_arr.append(cli)
for sep, cli in zip(s_arr, c_arr):
PotentialUtil.pass_single_message(self.join_tree, y, sep[1],
cli[1])
self.__walk__(y, sep[1], cli[1])
def initialize(join_tree):
"""
Starts the initialization.
:param join_tree: Join tree.
:return: Join tree.
"""
for clique in join_tree.get_cliques():
potential = PotentialUtil.get_potential_from_nodes(clique.nodes)
join_tree.add_potential(clique, potential)
for sep_set in join_tree.get_sep_sets():
potential = PotentialUtil.get_potential_from_nodes(sep_set.nodes)
join_tree.add_potential(sep_set, potential)
nodes = join_tree.get_bbn_nodes()
for node in nodes:
clique = Initializer.get_clique(node, join_tree)
# print('{} mapped to clique {}'.format(node.variable.name, clique))
p1 = join_tree.potentials[clique.id]
p2 = node.potential
# print(p1)
# print('>>>>>')
# print(p2)
# print('----')
PotentialUtil.multiply(p1, p2)
# print(p1)
# print('****')
for node in nodes:
for value in node.variable.values:
clique = node.metadata['parent.clique']
clique_potential = join_tree.potentials[clique.id]
node_potential = join_tree.get_evidence(node, value)
PotentialUtil.multiply(clique_potential, node_potential)
# print(clique)
# print(clique_potential)
return join_tree