def build_it(linesstring):
builder = SetGraphBuilder()
boxen = set()
for arc in StringIO.StringIO(linesstring):
parts = arc.split()
if not parts or parts[0].startswith("#"):
continue
if len(parts) == 1:
builder.add_node(*parts)
elif len(parts) == 2:
builder.add_arc(*parts)
else:
assert False, str(parts)
return FrozenGraph(builder)
def labels_to_lattice(labels):
"""
From a sequence of labels, build a linear lattice with labels on the arcs.
The result will have node labels which are guaranteed to be unique.
>>> label_dict = {'A': 1, 'B': 4, 'C': 9}
>>> labels_to_lattice(('A', 'B', 'C'))
FrozenGraph(GraphTables(((0, 1, 2, 3), (0, 1, 2), (1, 2, 3), ('A', 'B', 'C'))))
"""
gb = SetGraphBuilder()
counter = itertools.count()
start = gb.add_node(counter.next())
for l in labels:
end = gb.add_node(counter.next())
gb.add_arc(start, end, l)
start = end
return FrozenGraph(gb)
def build_it(linesstring):
builder = SetGraphBuilder()
boxen = set()
for arc in StringIO.StringIO(linesstring):
parts = arc.split()
if not parts or parts[0].startswith('#'):
continue
if len(parts) == 1:
builder.add_node(*parts)
elif len(parts) == 2:
builder.add_arc(*parts)
else:
assert False, str(parts)
return FrozenGraph(builder)
def labels_to_lattice(labels):
"""
From a sequence of labels, build a linear lattice with labels on the arcs.
The result will have node labels which are guaranteed to be unique.
>>> label_dict = {'A': 1, 'B': 4, 'C': 9}
>>> labels_to_lattice(('A', 'B', 'C'))
FrozenGraph(GraphTables(((0, 1, 2, 3), (0, 1, 2), (1, 2, 3), ('A', 'B', 'C'))))
"""
gb = SetGraphBuilder()
counter = itertools.count()
start = gb.add_node(counter.next())
for l in labels:
end = gb.add_node(counter.next())
gb.add_arc(start, end, l)
start = end
return FrozenGraph(gb)
def build_model_lattice(label_lattice, model_dict, epsilon_index):
"""
From a lattice with labels on the arcs and a dict mapping labels to model
indices, build a lattice with (node-index, model index) pairs on the nodes,
usable for constructing a TrainingGraph.
The resulting lattice may have new epsilon nodes as the new start and end
nodes; these will be given epsilon_index as their model indices. Note that
this function requires that label_lattice have unique labels on nodes. XXX
maybe do this node-labeling ourselves here?
>>> label_dict = {'A': 1, 'B': 4, 'C': 9}
>>> lat = labels_to_lattice(('A', 'B', 'C'))
>>> lat
FrozenGraph(GraphTables(((0, 1, 2, 3), (0, 1, 2), (1, 2, 3), ('A', 'B', 'C'))))
>>> result = build_model_lattice(lat, label_dict, 15)
>>> print result
FrozenGraph(GraphTables((((0, 1), (1, 4), (2, 9)), (0, 1), (1, 2), (None, None))))
# >>> result.dot_display()
"""
if not label_lattice.is_lattice() or label_lattice.has_self_loop():
raise ValueError("label_lattice is not a lattice or has a self loop")
counter = itertools.count()
# we need our node labels to be pairs of ints in which the first int is
# unique and the second is the index of the model from the callers
# label_dict
def model_node_labeler(pred_node_label, arc_label, succ_node_label):
if not model_dict.has_key(arc_label):
raise KeyError("Failed on lookup of label %s" % (arc_label))
model_index = model_dict[arc_label]
return (counter.next(), model_index)
def empty_arc_labeler(in_arc_label, node_label, out_arc_label):
return None
line_graph = label_lattice.get_line_graph(model_node_labeler,
empty_arc_labeler)
starts, ends = line_graph.get_terminals()
num_starts = len(starts)
num_ends = len(ends)
# If we started with a lattice, the line graph must have some terminals
assert num_starts >= 1 and num_ends >= 1
start_labels = (line_graph.get_label(node_id) for node_id in starts)
end_labels = (line_graph.get_label(node_id) for node_id in ends)
gb = SetGraphBuilder(line_graph)
# Tie terminals together with epsilons if necessary
if num_starts > 1:
new_start_label = gb.add_node((counter.next(), epsilon_index))
for node_label in start_labels:
gb.add_arc(new_start_label, node_label)
if num_ends > 1:
new_end_label = gb.add_node((counter.next(), epsilon_index))
for node_label in end_labels:
gb.new_arc(node_label, new_end_label)
return FrozenGraph(gb)
def build_model_lattice(label_lattice, model_dict, epsilon_index):
"""
From a lattice with labels on the arcs and a dict mapping labels to model
indices, build a lattice with (node-index, model index) pairs on the nodes,
usable for constructing a TrainingGraph.
The resulting lattice may have new epsilon nodes as the new start and end
nodes; these will be given epsilon_index as their model indices. Note that
this function requires that label_lattice have unique labels on nodes. XXX
maybe do this node-labeling ourselves here?
>>> label_dict = {'A': 1, 'B': 4, 'C': 9}
>>> lat = labels_to_lattice(('A', 'B', 'C'))
>>> lat
FrozenGraph(GraphTables(((0, 1, 2, 3), (0, 1, 2), (1, 2, 3), ('A', 'B', 'C'))))
>>> result = build_model_lattice(lat, label_dict, 15)
>>> print result
FrozenGraph(GraphTables((((0, 1), (1, 4), (2, 9)), (0, 1), (1, 2), (None, None))))
# >>> result.dot_display()
"""
if not label_lattice.is_lattice() or label_lattice.has_self_loop():
raise ValueError("label_lattice is not a lattice or has a self loop")
counter = itertools.count()
# we need our node labels to be pairs of ints in which the first int is
# unique and the second is the index of the model from the callers
# label_dict
def model_node_labeler(pred_node_label, arc_label, succ_node_label):
if not model_dict.has_key(arc_label):
raise KeyError("Failed on lookup of label %s" % (arc_label))
model_index = model_dict[arc_label]
return (counter.next(), model_index)
def empty_arc_labeler(in_arc_label, node_label, out_arc_label):
return None
line_graph = label_lattice.get_line_graph(model_node_labeler, empty_arc_labeler)
starts, ends = line_graph.get_terminals()
num_starts = len(starts)
num_ends = len(ends)
# If we started with a lattice, the line graph must have some terminals
assert num_starts >= 1 and num_ends >= 1
start_labels = (line_graph.get_label(node_id) for node_id in starts)
end_labels = (line_graph.get_label(node_id) for node_id in ends)
gb = SetGraphBuilder(line_graph)
# Tie terminals together with epsilons if necessary
if num_starts > 1:
new_start_label = gb.add_node((counter.next(), epsilon_index))
for node_label in start_labels:
gb.add_arc(new_start_label, node_label)
if num_ends > 1:
new_end_label = gb.add_node((counter.next(), epsilon_index))
for node_label in end_labels:
gb.new_arc(node_label, new_end_label)
return FrozenGraph(gb)
