def test_sum(self):
# Empty graph
self.assertTrue(gtn.equal(gtn.union([]), gtn.Graph()))
# Check single graph is a no-op
g1 = gtn.Graph()
g1.add_node(True)
g1.add_node(False, True)
g1.add_arc(0, 1, 1)
self.assertTrue(gtn.equal(gtn.union([g1]), g1))
# Simple union
g1 = gtn.Graph()
g1.add_node(True)
g1.add_node(False, True)
g1.add_arc(0, 1, 1)
g2 = gtn.Graph()
g2.add_node(True)
g2.add_node(False, True)
g2.add_arc(0, 1, 0)
expected = gtn.Graph()
expected.add_node(True)
expected.add_node(True)
expected.add_node(False, True)
expected.add_node(False, True)
expected.add_arc(0, 2, 1)
expected.add_arc(1, 3, 0)
self.assertTrue(gtn.isomorphic(gtn.union([g1, g2]), expected))
# Check adding with an empty graph works
g1 = gtn.Graph()
g1.add_node(True)
g1.add_node(False, True)
g1.add_arc(0, 1, 1)
g2 = gtn.Graph()
g3 = gtn.Graph()
g3.add_node(True, True)
g3.add_arc(0, 0, 2)
expected = gtn.Graph()
expected.add_node(True)
expected.add_node(False, True)
expected.add_node(True, True)
expected.add_arc(0, 1, 1)
expected.add_arc(2, 2, 2)
self.assertTrue(gtn.isomorphic(gtn.union([g1, g2, g3]), expected))
def forward_fn(g):
paths = [
gtn.viterbi_path(g),
gtn.viterbi_path(g),
gtn.viterbi_path(g)
]
return gtn.forward_score(gtn.union(paths))
def token_graph(token_list):
"""
Constructs a graph with all the individual
token transition models.
"""
tokens = []
for i, wp in enumerate(token_list):
# We can consume one or more consecutive
# word pieces for each emission:
# E.g. [ab, ab, ab] transduces to [ab]
graph = gtn.Graph()
graph.add_node(True)
graph.add_node(False, True)
graph.add_arc(0, 1, i, i)
graph.add_arc(1, 1, i, gtn.epsilon)
tokens.append(graph)
return gtn.closure(gtn.union(tokens))
def lexicon_graph(word_pieces, letters_to_idx):
"""
Constructs a graph which transudces letters to word pieces.
"""
lex = []
for i, wp in enumerate(word_pieces):
graph = gtn.Graph()
graph.add_node(True)
for e, l in enumerate(wp):
if e == len(wp) - 1:
graph.add_node(False, True)
graph.add_arc(e, e + 1, letters_to_idx[l], i)
else:
graph.add_node()
graph.add_arc(e, e + 1, letters_to_idx[l], gtn.epsilon)
lex.append(graph)
return gtn.closure(gtn.union(lex))
def test_sum_grad(self):
g1 = gtn.Graph()
g1.add_node(True)
g1.add_node()
g1.add_node(False, True)
g1.add_arc(0, 1, 0)
g1.add_arc(1, 2, 1)
# Works with a no gradient graph
g2 = gtn.Graph()(False)
g2.add_node(True)
g2.add_node()
g2.add_node(False, True)
g2.add_arc(0, 1, 0)
g2.add_arc(1, 2, 1)
g3 = gtn.Graph()
g3.add_node(True)
g3.add_node()
g3.add_node(False, True)
g3.add_arc(0, 1, 0)
g3.add_arc(1, 2, 1)
gtn.backward(gtn.forward_score(gtn.union([g1, g2, g3])))
def forward_fn1(g, g2=g2, g3=g3):
return gtn.forward_score(gtn.union([g, g2, g3]))
self.assertTrue(numerical_grad_check(forward_fn1, g1, 1e-4, 1e-3))
def forward_fn2(g, g1=g1, g2=g2):
return gtn.forward_score(gtn.union([g1, g2, g]))
self.assertTrue(numerical_grad_check(forward_fn2, g3, 1e-4, 1e-3))
CHECK_THROWS(g2.grad())
def forward_fn2(g, g1=g1, g2=g2):
return gtn.forward_score(gtn.union([g1, g2, g]))
def forward_fn1(g, g2=g2, g3=g3):
return gtn.forward_score(gtn.union([g, g2, g3]))
g1.add_node(False, True)
g1.add_arc(0, 1, 0)
g1.add_arc(1, 2, 1)
g1.add_arc(2, 2, 0)
# Recognizes "ba"
g2 = gtn.Graph(False)
g2.add_node(True)
g2.add_node()
g2.add_node(False, True)
g2.add_arc(0, 1, 1)
g2.add_arc(1, 2, 0)
# Recognizes "ac"
g3 = gtn.Graph(False)
g3.add_node(True)
g3.add_node()
g3.add_node(False, True)
g3.add_arc(0, 1, 0)
g3.add_arc(1, 2, 2)
symbols = {0: "a", 1: "b", 2: "c"}
gtn.draw(g1, "/tmp/union_g1.pdf", symbols, symbols)
gtn.draw(g2, "/tmp/union_g2.pdf", symbols, symbols)
gtn.draw(g3, "/tmp/union_g3.pdf", symbols, symbols)
graph = gtn.union([g1, g2, g3])
gtn.draw(graph, "/tmp/union_graph.pdf", symbols, symbols)