def test_heuristic_first_steps(self):
"""Test first steps of min_fill_in heuristic"""
graph = {
n: set(self.deterministic_graph[n]) - set([n])
for n in self.deterministic_graph
}
print("Graph {}:".format(graph))
elim_node = min_fill_in_heuristic(graph)
steps = []
while elim_node is not None:
print("Removing {}:".format(elim_node))
steps.append(elim_node)
nbrs = graph[elim_node]
for u, v in itertools.permutations(nbrs, 2):
if v not in graph[u]:
graph[u].add(v)
for u in graph:
if elim_node in graph[u]:
graph[u].remove(elim_node)
del graph[elim_node]
print("Graph {}:".format(graph))
elim_node = min_fill_in_heuristic(graph)
# check only the first 2 elements for equality
assert_equals(steps[:2], [6, 5])
def test_heuristic_first_steps(self):
"""Test first steps of min_fill_in heuristic"""
graph = {n: set(self.deterministic_graph[n]) - set([n])
for n in self.deterministic_graph}
print("Graph {}:".format(graph))
elim_node = min_fill_in_heuristic(graph)
steps = []
while elim_node is not None:
print("Removing {}:".format(elim_node))
steps.append(elim_node)
nbrs = graph[elim_node]
for u, v in itertools.permutations(nbrs, 2):
if v not in graph[u]:
graph[u].add(v)
for u in graph:
if elim_node in graph[u]:
graph[u].remove(elim_node)
del graph[elim_node]
print("Graph {}:".format(graph))
elim_node = min_fill_in_heuristic(graph)
# check only the first 2 elements for equality
assert_equals(steps[:2], [6, 5])
def treeDecomposition(G):
tree = []
graph = {n: set(G[n]) - set([n]) for n in G}
node_stack = []
elim_node = treewidth.min_fill_in_heuristic(graph)
while elim_node is not None:
neigh = graph[elim_node]
for u, v in itertools.permutations(neigh, 2):
if v not in graph[u]:
graph[u].add(v)
node_stack.append((elim_node, neigh))
for u in graph[elim_node]:
graph[u].remove(elim_node)
del graph[elim_node]
elim_node = treewidth.min_fill_in_heuristic(graph)
decomp = nx.Graph()
first_bag = frozenset(graph.keys())
tree.append(set(graph.keys()))
decomp.add_node(first_bag)
while node_stack:
# get node and its neighbors from the stack
(curr_node, nbrs) = node_stack.pop()
# find a bag all neighbors are in
old_bag = None
for bag in decomp.nodes:
if nbrs <= bag:
old_bag = bag
break
if old_bag is None:
# no old_bag was found: just connect to the first_bag
old_bag = first_bag
# create new node for decomposition
nbrs.add(curr_node)
new_bag = frozenset(nbrs)
# add edge to decomposition (implicitly also adds the new node)
decomp.add_edge(old_bag, new_bag)
tree.append((nbrs))
return tree, decomp
def test_heuristic_abort(self):
"""Test if min_fill_in returns None for fully connected graph"""
graph = {}
for u in self.complete:
graph[u] = set()
for v in self.complete[u]:
if u != v: # ignore self-loop
graph[u].add(v)
next_node = min_fill_in_heuristic(graph)
if next_node is None:
pass
else:
assert False
def test_heuristic_abort(self):
"""Test if min_fill_in returns None for fully connected graph"""
graph = {}
for u in self.complete:
graph[u] = set()
for v in self.complete[u]:
if u != v: # ignore self-loop
graph[u].add(v)
next_node = min_fill_in_heuristic(graph)
if next_node is None:
pass
else:
assert False
def treeDecomposition(G):
# T = nx.Graph()
# nodeList = copy.deepcopy(G.nodes())
# tree = list()
#
# for i in nodeList:
# vertex = i
# bag = list()
# bag.append(vertex)
#
# for j in T.neighbors(i):
# bag.append(j)
# tree.append((bag))
# T.add_node(frozenset(bag))
# G.remove_node(i)
#
# for n1 in range(len(nodeList)):
# checker = False
# for n2 in range(n1+1, len(nodeList)):
# if checker == False and len(nodeList[n1].intersection(nodeList[n2])) > 0:
# T.add_edge(nodeList[n1], nodeList[n2])
# checker = True
#
# nx.draw(T, with_labels=True, font_weight='bold')
tree = []
graph = {n: set(G[n]) - set([n]) for n in G}
node_stack = []
elim_node = treewidth.min_fill_in_heuristic(graph)
while elim_node is not None:
neigh = graph[elim_node]
for u, v in itertools.permutations(neigh, 2):
if v not in graph[u]:
graph[u].add(v)
node_stack.append((elim_node, neigh))
for u in graph[elim_node]:
graph[u].remove(elim_node)
del graph[elim_node]
elim_node = treewidth.min_fill_in_heuristic(graph)
decomp = nx.Graph()
first_bag = frozenset(graph.keys())
tree.append(set(graph.keys()))
decomp.add_node(first_bag)
while node_stack:
# get node and its neighbors from the stack
(curr_node, nbrs) = node_stack.pop()
# find a bag all neighbors are in
old_bag = None
for bag in decomp.nodes:
if nbrs <= bag:
old_bag = bag
break
if old_bag is None:
# no old_bag was found: just connect to the first_bag
old_bag = first_bag
# create new node for decomposition
nbrs.add(curr_node)
new_bag = frozenset(nbrs)
# add edge to decomposition (implicitly also adds the new node)
decomp.add_edge(old_bag, new_bag)
tree.append((nbrs))
return tree, decomp
