Pseudocode for parser

This commit is contained in:
Matthew Honnibal 2017-05-04 12:17:36 +02:00
parent 6e1fad92a1
commit ccaf26206b
2 changed files with 133 additions and 205 deletions

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@ -1,6 +1,4 @@
from thinc.linear.avgtron cimport AveragedPerceptron
from thinc.typedefs cimport atom_t
from thinc.structs cimport FeatureC
from .stateclass cimport StateClass
from .arc_eager cimport TransitionSystem
@ -10,15 +8,10 @@ from ..structs cimport TokenC
from ._state cimport StateC
cdef class ParserModel(AveragedPerceptron):
cdef int set_featuresC(self, atom_t* context, FeatureC* features,
const StateC* state) nogil
cdef class Parser:
cdef readonly Vocab vocab
cdef readonly ParserModel model
cdef readonly object model
cdef readonly TransitionSystem moves
cdef readonly object cfg
cdef int parseC(self, TokenC* tokens, int length, int nr_feat) nogil
#cdef int parseC(self, TokenC* tokens, int length, int nr_feat) nogil

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@ -49,78 +49,67 @@ def set_debug(val):
DEBUG = val
def get_templates(name):
pf = _parse_features
if name == 'ner':
return pf.ner
elif name == 'debug':
return pf.unigrams
elif name.startswith('embed'):
return (pf.words, pf.tags, pf.labels)
else:
return (pf.unigrams + pf.s0_n0 + pf.s1_n0 + pf.s1_s0 + pf.s0_n1 + pf.n0_n1 + \
pf.tree_shape + pf.trigrams)
@layerize
def get_context_tokens(states, drop=0.):
for state in states:
context[i, 0] = state.B(0)
context[i, 1] = state.S(0)
context[i, 2] = state.S(1)
context[i, 3] = state.L(state.S(0), 1)
context[i, 4] = state.L(state.S(0), 2)
context[i, 5] = state.R(state.S(0), 1)
context[i, 6] = state.R(state.S(0), 2)
return (context, states), None
cdef class ParserModel(AveragedPerceptron):
cdef int set_featuresC(self, atom_t* context, FeatureC* features,
const StateC* state) nogil:
fill_context(context, state)
nr_feat = self.extracter.set_features(features, context)
return nr_feat
def extract_features(attrs):
def forward(contexts_states, drop=0.):
contexts, states = contexts_states
for i, state in enumerate(states):
for j, tok_i in enumerate(contexts[i]):
token = state.get_token(tok_i)
for k, attr in enumerate(attrs):
output[i, j, k] = getattr(token, attr)
return output, None
return layerize(forward)
def update(self, Example eg, itn=0):
"""
Does regression on negative cost. Sort of cute?
"""
self.time += 1
cdef int best = arg_max_if_gold(eg.c.scores, eg.c.costs, eg.c.nr_class)
cdef int guess = eg.guess
if guess == best or best == -1:
return 0.0
cdef FeatureC feat
cdef int clas
cdef weight_t gradient
if USE_FTRL:
for feat in eg.c.features[:eg.c.nr_feat]:
for clas in range(eg.c.nr_class):
if eg.c.is_valid[clas] and eg.c.scores[clas] >= eg.c.scores[best]:
gradient = eg.c.scores[clas] + eg.c.costs[clas]
self.update_weight_ftrl(feat.key, clas, feat.value * gradient)
else:
for feat in eg.c.features[:eg.c.nr_feat]:
self.update_weight(feat.key, guess, feat.value * eg.c.costs[guess])
self.update_weight(feat.key, best, -feat.value * eg.c.costs[guess])
return eg.c.costs[guess]
def update_from_histories(self, TransitionSystem moves, Doc doc, histories, weight_t min_grad=0.0):
cdef Pool mem = Pool()
features = <FeatureC*>mem.alloc(self.nr_feat, sizeof(FeatureC))
def build_tok2vec(lang, width, depth, embed_size):
cols = [LEX_ID, PREFIX, SUFFIX, SHAPE]
static = StaticVectors('en', width, column=cols.index(LEX_ID))
prefix = HashEmbed(width, embed_size, column=cols.index(PREFIX))
suffix = HashEmbed(width, embed_size, column=cols.index(SUFFIX))
shape = HashEmbed(width, embed_size, column=cols.index(SHAPE))
with Model.overload_operaters('>>': chain, '|': concatenate, '+': add):
tok2vec = (
extract_features(cols)
>> (static | prefix | suffix | shape)
>> (ExtractWindow(nW=1) >> Maxout(width)) ** depth
)
return tok2vec
cdef StateClass stcls
cdef class_t clas
self.time += 1
cdef atom_t[CONTEXT_SIZE] atoms
histories = [(grad, hist) for grad, hist in histories if abs(grad) >= min_grad and hist]
if not histories:
return None
gradient = [Counter() for _ in range(max([max(h)+1 for _, h in histories]))]
for d_loss, history in histories:
stcls = StateClass.init(doc.c, doc.length)
moves.initialize_state(stcls.c)
for clas in history:
nr_feat = self.set_featuresC(atoms, features, stcls.c)
clas_grad = gradient[clas]
for feat in features[:nr_feat]:
clas_grad[feat.key] += d_loss * feat.value
moves.c[clas].do(stcls.c, moves.c[clas].label)
cdef feat_t key
cdef weight_t d_feat
for clas, clas_grad in enumerate(gradient):
for key, d_feat in clas_grad.items():
if d_feat != 0:
self.update_weight_ftrl(key, clas, d_feat)
def build_parse2vec(width, embed_size):
cols = [TAG, DEP]
tag_vector = HashEmbed(width, 1000, column=cols.index(TAG))
dep_vector = HashEmbed(width, 1000, column=cols.index(DEP))
with Model.overload_operaters('>>': chain):
model = (
extract_features([TAG, DEP])
>> (tag_vector | dep_vector)
)
return model
def build_model(get_contexts, tok2vec, parse2vec, width, depth, nr_class):
with Model.overload_operaters('>>': chain):
model = (
get_contexts
>> (tok2vec | parse2vec)
>> Maxout(width) ** depth
>> Softmax(nr_class)
)
return model
cdef class Parser:
@ -144,15 +133,6 @@ cdef class Parser:
"""
with (path / 'config.json').open() as file_:
cfg = ujson.load(file_)
# TODO: remove this shim when we don't have to support older data
if 'labels' in cfg and 'actions' not in cfg:
cfg['actions'] = cfg.pop('labels')
# TODO: remove this shim when we don't have to support older data
for action_name, labels in dict(cfg.get('actions', {})).items():
# We need this to be sorted
if isinstance(labels, dict):
labels = list(sorted(labels.keys()))
cfg['actions'][action_name] = labels
self = cls(vocab, TransitionSystem=TransitionSystem, model=None, **cfg)
if (path / 'model').exists():
self.model.load(str(path / 'model'))
@ -161,14 +141,14 @@ cdef class Parser:
"Required file %s/model not found when loading" % str(path))
return self
def __init__(self, Vocab vocab, TransitionSystem=None, ParserModel model=None, **cfg):
def __init__(self, Vocab vocab, TransitionSystem=None, model=None, **cfg):
"""
Create a Parser.
Arguments:
vocab (Vocab):
The vocabulary object. Must be shared with documents to be processed.
model (thinc.linear.AveragedPerceptron):
model (thinc Model):
The statistical model.
Returns (Parser):
The newly constructed object.
@ -178,44 +158,40 @@ cdef class Parser:
self.vocab = vocab
cfg['actions'] = TransitionSystem.get_actions(**cfg)
self.moves = TransitionSystem(vocab.strings, cfg['actions'])
# TODO: Remove this when we no longer need to support old-style models
if isinstance(cfg.get('features'), basestring):
cfg['features'] = get_templates(cfg['features'])
elif 'features' not in cfg:
cfg['features'] = self.feature_templates
self.model = ParserModel(cfg['features'])
self.model.l1_penalty = cfg.get('L1', 0.0)
self.model.learn_rate = cfg.get('learn_rate', 0.001)
if model is None:
model = self.build_model(**cfg)
self.model = model
self.cfg = cfg
# TODO: This is a pretty hacky fix to the problem of adding more
# labels. The issue is they come in out of order, if labels are
# added during training
for label in cfg.get('extra_labels', []):
self.add_label(label)
def __reduce__(self):
return (Parser, (self.vocab, self.moves, self.model), None, None)
def __call__(self, Doc tokens):
"""
Apply the entity recognizer, setting the annotations onto the Doc object.
Apply the parser or entity recognizer, setting the annotations onto the Doc object.
Arguments:
doc (Doc): The document to be processed.
Returns:
None
"""
cdef int nr_feat = self.model.nr_feat
with nogil:
status = self.parseC(tokens.c, tokens.length, nr_feat)
# Check for KeyboardInterrupt etc. Untested
PyErr_CheckSignals()
if status != 0:
raise ParserStateError(tokens)
self.parse_batch([tokens])
self.moves.finalize_doc(tokens)
def parse_batch(self, docs):
states = self._init_states(docs)
todo = list(states)
nr_class = self.moves.n_moves
while todo:
scores = self.model.predict(todo)
self._validate_batch(is_valid, scores, states)
for state, guess in zip(todo, scores.argmax(axis=1)):
action = self.moves.c[guess]
action.do(state, action.label)
todo = [state for state in todo if not state.is_final()]
for state, doc in zip(states, docs):
self.moves.finalize_state(state, doc)
def pipe(self, stream, int batch_size=1000, int n_threads=2):
"""
Process a stream of documents.
@ -229,7 +205,6 @@ cdef class Parser:
Yields (Doc): Documents, in order.
"""
cdef Pool mem = Pool()
cdef TokenC** doc_ptr = <TokenC**>mem.alloc(batch_size, sizeof(TokenC*))
cdef int* lengths = <int*>mem.alloc(batch_size, sizeof(int))
cdef Doc doc
cdef int i
@ -241,111 +216,71 @@ cdef class Parser:
lengths[len(queue)] = doc.length
queue.append(doc)
if len(queue) == batch_size:
with nogil:
for i in cython.parallel.prange(batch_size, num_threads=n_threads):
status = self.parseC(doc_ptr[i], lengths[i], nr_feat)
if status != 0:
with gil:
raise ParserStateError(queue[i])
PyErr_CheckSignals()
self.parse_batch(queue)
for doc in queue:
self.moves.finalize_doc(doc)
yield doc
queue = []
batch_size = len(queue)
with nogil:
for i in cython.parallel.prange(batch_size, num_threads=n_threads):
status = self.parseC(doc_ptr[i], lengths[i], nr_feat)
if status != 0:
with gil:
raise ParserStateError(queue[i])
PyErr_CheckSignals()
if queue:
self.parse_batch(queue)
for doc in queue:
self.moves.finalize_doc(doc)
yield doc
cdef int parseC(self, TokenC* tokens, int length, int nr_feat) nogil:
state = new StateC(tokens, length)
# NB: This can change self.moves.n_moves!
# I think this causes memory errors if called by .pipe()
self.moves.initialize_state(state)
def update(self, docs, golds, drop=0., sgd=None):
if isinstance(docs, Doc) and isinstance(golds, GoldParse):
return self.update([docs], [golds], drop=drop)
states = self._init_states(docs)
nr_class = self.moves.n_moves
while states:
scores, finish_update = self.model.begin_update(states, drop=drop)
self._validate_batch(is_valid, scores, states)
for i, state in enumerate(states):
self.moves.set_costs(costs[i], is_valid, state, golds[i])
cdef ExampleC eg
eg.nr_feat = nr_feat
eg.nr_atom = CONTEXT_SIZE
eg.nr_class = nr_class
eg.features = <FeatureC*>calloc(sizeof(FeatureC), nr_feat)
eg.atoms = <atom_t*>calloc(sizeof(atom_t), CONTEXT_SIZE)
eg.scores = <weight_t*>calloc(sizeof(weight_t), nr_class)
eg.is_valid = <int*>calloc(sizeof(int), nr_class)
cdef int i
while not state.is_final():
eg.nr_feat = self.model.set_featuresC(eg.atoms, eg.features, state)
self.moves.set_valid(eg.is_valid, state)
self.model.set_scoresC(eg.scores, eg.features, eg.nr_feat)
self._transition_batch(states, scores)
self._set_gradient(gradients, scores, costs)
finish_update(gradients, sgd=sgd)
gradients.fill(0)
guess = VecVec.arg_max_if_true(eg.scores, eg.is_valid, eg.nr_class)
if guess < 0:
return 1
action = self.moves.c[guess]
action.do(state, action.label)
memset(eg.scores, 0, sizeof(eg.scores[0]) * eg.nr_class)
for i in range(eg.nr_class):
eg.is_valid[i] = 1
self.moves.finalize_state(state)
for i in range(length):
tokens[i] = state._sent[i]
del state
free(eg.features)
free(eg.atoms)
free(eg.scores)
free(eg.is_valid)
states = [state for state in states if not state.is_final()]
gradients = gradients[:len(states)]
costs = costs[:len(states)]
return 0
def update(self, Doc tokens, GoldParse gold, itn=0, double drop=0.0):
"""
Update the statistical model.
Arguments:
doc (Doc):
The example document for the update.
gold (GoldParse):
The gold-standard annotations, to calculate the loss.
Returns (float):
The loss on this example.
"""
self.moves.preprocess_gold(gold)
cdef StateClass stcls = StateClass.init(tokens.c, tokens.length)
self.moves.initialize_state(stcls.c)
cdef Pool mem = Pool()
cdef Example eg = Example(
nr_class=self.moves.n_moves,
nr_atom=CONTEXT_SIZE,
nr_feat=self.model.nr_feat)
cdef weight_t loss = 0
cdef Transition action
cdef double dropout_rate = self.cfg.get('dropout', drop)
while not stcls.is_final():
eg.c.nr_feat = self.model.set_featuresC(eg.c.atoms, eg.c.features,
stcls.c)
dropout(eg.c.features, eg.c.nr_feat, dropout_rate)
self.moves.set_costs(eg.c.is_valid, eg.c.costs, stcls, gold)
self.model.set_scoresC(eg.c.scores, eg.c.features, eg.c.nr_feat)
guess = VecVec.arg_max_if_true(eg.c.scores, eg.c.is_valid, eg.c.nr_class)
self.model.update(eg)
def _validate_batch(self, is_valid, scores, states):
for i, state in enumerate(states):
self.moves.set_valid(is_valid, state)
for j in range(self.moves.n_moves):
if not is_valid[j]:
scores[i, j] = 0
def _transition_batch(self, states, scores):
for state, guess in zip(states, scores.argmax(axis=1)):
action = self.moves.c[guess]
action.do(stcls.c, action.label)
loss += eg.costs[guess]
eg.fill_scores(0, eg.c.nr_class)
eg.fill_costs(0, eg.c.nr_class)
eg.fill_is_valid(1, eg.c.nr_class)
action.do(state, action.label)
self.moves.finalize_state(stcls.c)
return loss
def _init_states(self, docs):
states = []
cdef Doc doc
for i, doc in enumerate(docs):
state = StateClass.init(doc)
self.moves.initialize_state(state)
return states
def _set_gradient(self, gradients, scores, costs):
"""Do multi-label log loss"""
cdef double Z, gZ, max_, g_max
maxes = scores.max(axis=1)
g_maxes = (scores * costs <= 0).max(axis=1)
exps = (scores-maxes).exp()
g_exps = (g_scores-g_maxes).exp()
Zs = exps.sum(axis=1)
gZs = g_exps.sum(axis=1)
logprob = exps / Zs
g_logprob = g_exps / gZs
gradients[:] = logprob - g_logprob
def step_through(self, Doc doc, GoldParse gold=None):
"""