Refactor model for beam parser, to avoid conditionals on model type

This commit is contained in:
Matthew Honnibal 2016-07-29 19:33:01 +02:00
parent a57f337d29
commit 6b912731f8
2 changed files with 61 additions and 115 deletions

View File

@ -22,6 +22,8 @@ from ._parse_features cimport fill_context
from ._parse_features cimport CONTEXT_SIZE
from ._parse_features cimport fill_context
from ._parse_features cimport *
from .transition_system cimport TransitionSystem
from ..tokens.doc cimport Doc
cdef class ParserPerceptron(AveragedPerceptron):
@ -51,6 +53,23 @@ cdef class ParserPerceptron(AveragedPerceptron):
fill_context(eg.atoms, state)
eg.nr_feat = self.extracter.set_features(eg.features, eg.atoms)
def _update_from_history(self, TransitionSystem moves, Doc doc, history, weight_t grad):
cdef Pool mem = Pool()
cdef atom_t[CONTEXT_SIZE] context
features = <FeatureC*>mem.alloc(self.nr_feat, sizeof(FeatureC))
cdef StateClass stcls = StateClass.init(doc.c, doc.length)
moves.initialize_state(stcls.c)
cdef class_t clas
self.time += 1
for clas in history:
fill_context(context, stcls.c)
nr_feat = self.extracter.set_features(features, context)
for feat in features[:nr_feat]:
self.update_weight(feat.key, clas, feat.value * grad)
moves.c[clas].do(stcls.c, moves.c[clas].label)
cdef class ParserNeuralNet(NeuralNet):
def __init__(self, shape, **kwargs):
@ -123,6 +142,41 @@ cdef class ParserNeuralNet(NeuralNet):
cdef void _softmaxC(self, weight_t* out) nogil:
pass
def _update_from_history(self, TransitionSystem moves, Doc doc, history, weight_t grad):
cdef Example py_eg = Example(nr_class=moves.n_moves, nr_atom=CONTEXT_SIZE,
nr_feat=self.nr_feat, widths=self.widths)
stcls = StateClass.init(doc.c, doc.length)
moves.initialize_state(stcls.c)
cdef uint64_t[2] key
key[0] = hash64(doc.c, sizeof(TokenC) * doc.length, 0)
key[1] = 0
cdef uint64_t clas
for clas in history:
self.set_featuresC(py_eg.c, stcls.c)
moves.set_valid(py_eg.c.is_valid, stcls.c)
# Update with a sparse gradient: everything's 0, except our class.
# Remember, this is a component of the global update. It's not our
# "job" here to think about the other beam candidates. We just want
# to work on this sequence. However, other beam candidates will
# have gradients that refer to the same state.
# We therefore have a key that indicates the current sequence, so that
# the model can merge updates that refer to the same state together,
# by summing their gradients.
memset(py_eg.c.costs, 0, self.moves.n_moves)
py_eg.c.costs[clas] = grad
self.updateC(
py_eg.c.features, py_eg.c.nr_feat, True, py_eg.c.costs, py_eg.c.is_valid,
False, key=key[0])
moves.c[clas].do(stcls.c, self.moves.c[clas].label)
py_eg.c.reset()
# Build a hash of the state sequence.
# Position 0 represents the previous sequence, position 1 the new class.
# So we want to do:
# key.prev = hash((key.prev, key.new))
# key.new = clas
key[1] = clas
key[0] = hash64(key, sizeof(key), 0)
cdef inline FeatureC* _add_token(FeatureC* feats,
int slot, const TokenC* token, weight_t value) nogil:

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@ -113,33 +113,12 @@ cdef class BeamParser(Parser):
break
else:
violn.check_crf(pred, gold)
if isinstance(self.model, ParserNeuralNet):
min_grad = 0.1 ** (itn+1)
for grad, hist in zip(violn.p_probs, violn.p_hist):
assert not math.isnan(grad) and not math.isinf(grad)
if abs(grad) >= min_grad:
self._update_dense(tokens, hist, grad)
for grad, hist in zip(violn.g_probs, violn.g_hist):
assert not math.isnan(grad) and not math.isinf(grad)
if abs(grad) >= min_grad:
self._update_dense(tokens, hist, grad)
else:
self.model.time += 1
#min_grad = 0.01 ** (itn+1)
#for grad, hist in zip(violn.p_probs, violn.p_hist):
# assert not math.isnan(grad)
# assert not math.isinf(grad)
# if abs(grad) >= min_grad:
# self._update(tokens, hist, -grad)
#for grad, hist in zip(violn.g_probs, violn.g_hist):
# assert not math.isnan(grad)
# assert not math.isinf(grad)
# if abs(grad) >= min_grad:
# self._update(tokens, hist, -grad)
if violn.p_hist:
self._update(tokens, violn.p_hist[0], -1.0)
if violn.g_hist:
self._update(tokens, violn.g_hist[0], 1.0)
min_grad = 0.1 ** (itn+1)
histories = zip(violn.p_probs, violn.p_hist) + zip(violn.g_probs, violn.g_hist)
for grad, hist in histories:
assert not math.isnan(grad) and not math.isinf(grad)
if abs(grad) >= min_grad:
self._update_from_history(self.moves, tokens, hist, grad)
_cleanup(pred)
_cleanup(gold)
return pred.loss
@ -149,16 +128,11 @@ cdef class BeamParser(Parser):
nr_feat=self.model.nr_feat, widths=self.model.widths)
cdef ExampleC* eg = py_eg.c
cdef ParserNeuralNet nn_model
cdef ParserPerceptron ap_model
for i in range(beam.size):
py_eg.reset()
stcls = <StateClass>beam.at(i)
if not stcls.c.is_final():
if isinstance(self.model, ParserNeuralNet):
ParserNeuralNet.set_featuresC(self.model, eg, stcls.c)
else:
ParserPerceptron.set_featuresC(self.model, eg, stcls.c)
self.model.set_featuresC(eg, stcls.c)
self.model.set_scoresC(beam.scores[i], eg.features, eg.nr_feat, 1)
self.moves.set_valid(beam.is_valid[i], stcls.c)
if gold is not None:
@ -173,59 +147,6 @@ cdef class BeamParser(Parser):
beam.advance(_transition_state, _hash_state, <void*>self.moves.c)
beam.check_done(_check_final_state, NULL)
def _update_dense(self, Doc doc, history, weight_t loss):
cdef Example py_eg = Example(nr_class=self.moves.n_moves, nr_atom=CONTEXT_SIZE,
nr_feat=self.model.nr_feat, widths=self.model.widths)
cdef ExampleC* eg = py_eg.c
cdef ParserNeuralNet model = self.model
stcls = StateClass.init(doc.c, doc.length)
self.moves.initialize_state(stcls.c)
cdef uint64_t[2] key
key[0] = hash64(doc.c, sizeof(TokenC) * doc.length, 0)
key[1] = 0
cdef uint64_t clas
for clas in history:
model.set_featuresC(eg, stcls.c)
self.moves.set_valid(eg.is_valid, stcls.c)
# Update with a sparse gradient: everything's 0, except our class.
# Remember, this is a component of the global update. It's not our
# "job" here to think about the other beam candidates. We just want
# to work on this sequence. However, other beam candidates will
# have gradients that refer to the same state.
# We therefore have a key that indicates the current sequence, so that
# the model can merge updates that refer to the same state together,
# by summing their gradients.
memset(eg.costs, 0, self.moves.n_moves)
eg.costs[clas] = loss
model.updateC(
eg.features, eg.nr_feat, True, eg.costs, eg.is_valid, False, key=key[0])
self.moves.c[clas].do(stcls.c, self.moves.c[clas].label)
py_eg.reset()
# Build a hash of the state sequence.
# Position 0 represents the previous sequence, position 1 the new class.
# So we want to do:
# key.prev = hash((key.prev, key.new))
# key.new = clas
key[1] = clas
key[0] = hash64(key, sizeof(key), 0)
def _update(self, Doc tokens, list hist, weight_t inc):
cdef Pool mem = Pool()
cdef atom_t[CONTEXT_SIZE] context
features = <FeatureC*>mem.alloc(self.model.nr_feat, sizeof(FeatureC))
cdef StateClass stcls = StateClass.init(tokens.c, tokens.length)
self.moves.initialize_state(stcls.c)
cdef class_t clas
cdef ParserPerceptron model = self.model
for clas in hist:
fill_context(context, stcls.c)
nr_feat = model.extracter.set_features(features, context)
for feat in features[:nr_feat]:
model.update_weight(feat.key, clas, feat.value * inc)
self.moves.c[clas].do(stcls.c, self.moves.c[clas].label)
# These are passed as callbacks to thinc.search.Beam
cdef int _transition_state(void* _dest, void* _src, class_t clas, void* _moves) except -1:
@ -261,32 +182,3 @@ def _cleanup(Beam beam):
cdef hash_t _hash_state(void* _state, void* _) except 0:
state = <StateClass>_state
return state.c.hash()
# def _early_update(self, Doc doc, Beam pred, Beam gold):
# # Gather the partition function --- Z --- by which we can normalize the
# # scores into a probability distribution. The simple idea here is that
# # we clip the probability of all parses outside the beam to 0.
# cdef long double Z = 0.0
# for i in range(pred.size):
# # Make sure we've only got negative examples here.
# # Otherwise, we might double-count the gold.
# if pred._states[i].loss > 0:
# Z += exp(pred._states[i].score)
# cdef weight_t grad
# if Z > 0: # If no negative examples, don't update.
# Z += exp(gold.score)
# for i, hist in enumerate(pred.histories):
# if pred._states[i].loss > 0:
# # Update with the negative example.
# # Gradient of loss is P(parse) - 0
# grad = exp(pred._states[i].score) / Z
# if abs(grad) >= 0.01:
# self._update_dense(doc, hist, grad)
# # Update with the positive example.
# # Gradient of loss is P(parse) - 1
# grad = (exp(gold.score) / Z) - 1
# if abs(grad) >= 0.01:
# self._update_dense(doc, gold.histories[0], grad)
#
#