* Refactor CharacterTagger

This commit is contained in:
Matthew Honnibal 2016-02-24 18:17:16 +01:00
parent 92e9134603
commit fab538672e

View File

@ -1,4 +1,5 @@
from __future__ import unicode_literals
cimport cython
import json
from os import path
from collections import defaultdict
@ -10,6 +11,7 @@ from thinc.extra.eg cimport Example
from thinc.structs cimport ExampleC
from thinc.linear.avgtron cimport AveragedPerceptron
from thinc.linalg cimport VecVec
from thinc.structs cimport FeatureC
from .typedefs cimport attr_t
from .tokens.doc cimport Doc
@ -125,14 +127,29 @@ cdef class TaggerNeuralNet(NeuralNet):
cdef class CharacterTagger(NeuralNet):
def __init__(self, n_classes,
depth=4, hidden_width=50,
chars_width=10,
words_width=20, shape_width=5, suffix_width=5, tags_width=20,
learn_rate=0.1):
input_length = 5 * chars_width * self.chars_per_word + 2 * tags_width
widths = [input_length] + [hidden_width] * depth + [n_classes]
depth=3, hidden_width=100, chars_width=5, tags_width=10, learn_rate=0.1,
left_window=2, right_window=2, tags_window=10, chars_per_word=8):
self.chars_per_word = chars_per_word
self.chars_width = chars_width
self.tags_width = tags_width
self.left_window = left_window
self.right_window = right_window
self.tags_window = tags_window
self.depth = depth
self.hidden_width = hidden_width
input_length = self.left_window * self.chars_width * self.chars_per_word \
+ self.right_window * self.chars_width * self.chars_per_word \
+ 1 * self.chars_width * self.chars_per_word \
+ self.tags_window * self.tags_width
widths = [input_length] + [self.hidden_width] * self.depth + [n_classes]
vector_widths = [chars_width, tags_width]
slots = [0] * 5 * self.chars_per_word + [1] * 2
slots = [0] * self.left_window * self.chars_per_word \
+ [0] * self.right_window * self.chars_per_word \
+ [0] * 1 * self.chars_per_word \
+ [1] * self.tags_window
NeuralNet.__init__(
self,
widths,
@ -141,36 +158,30 @@ cdef class CharacterTagger(NeuralNet):
rho=1e-6,
update_step='sgd')
cdef void set_featuresC(self, ExampleC* eg, const TokenC* tokens, object strings, int i) except *:
oov = '_' * self.chars_per_word
cdef void set_featuresC(self, ExampleC* eg,
const TokenC* tokens, object strings, const int i) except *:
cdef unicode oov = ''
p2 = strings[i-2] if i >= 2 else oov
p1 = strings[i-1] if i >= 1 else oov
w = strings[i]
n1 = strings[i+1] if (i+1) < len(strings) else oov
n2 = strings[i+2] if (i+2) < len(strings) else oov
cdef int p = 0
cdef int c
cdef int chars_per_word = self.chars_per_word
cdef unicode string
eg.nr_feat = 0
for string in (p2, p1, w, n1, n2):
for c in range(chars_per_word / 2):
eg.features[p].i = p
eg.features[p].key = ord(string[c])
eg.features[p].value = 1.0 if string[c] != u'_' else 0.0
p += 1
eg.features[p].i = p
eg.features[p].key = ord(string[-(c+1)])
eg.features[p].value = 1.0 if string[-(c+1)] != u'_' else 0.0
p += 1
eg.features[p].key = tokens[i-1].tag
eg.features[p].value = 1.0
eg.features[p].i = p
p += 1
eg.features[p].key = tokens[i-2].tag
eg.features[p].value = 1.0
eg.features[p].i = p
eg.nr_feat = p+1
set_character_features(&eg.features[eg.nr_feat],
string, chars_per_word)
eg.nr_feat += chars_per_word
cdef int hist
for hist in range(1, self.tags_window+1):
tag = tokens[i-hist].tag if hist <= i else 0
eg.features[eg.nr_feat].key = tag
eg.features[eg.nr_feat].value = 1.0
eg.nr_feat += 1
cdef int p
for p in range(eg.nr_feat):
eg.features[p].i = p
def end_training(self):
pass
@ -179,24 +190,9 @@ cdef class CharacterTagger(NeuralNet):
property nr_feat:
def __get__(self):
return self.chars_per_word * 5 + 2
nr_word = self.left_window + self.right_window + 1
return self.chars_per_word * nr_word + self.tags_window
property chars_per_word:
def __get__(self):
return 16
def _pad(word, nr_char):
if len(word) == nr_char:
pass
elif len(word) > nr_char:
split = nr_char / 2
word = word[:split] + word[-split:]
else:
word = word.ljust(nr_char, '_')
assert len(word) == nr_char, repr(word)
return word
cdef inline void _fill_from_token(atom_t* context, const TokenC* t) nogil:
context[0] = t.lex.lower
@ -293,9 +289,6 @@ cdef class Tagger:
def tag_names(self):
return self.vocab.morphology.tag_names
def __reduce__(self):
return (self.__class__, (self.vocab, self.model), None, None)
def tag_from_strings(self, Doc tokens, object tag_strs):
cdef int i
for i in range(tokens.length):
@ -319,14 +312,13 @@ cdef class Tagger:
widths=self.model.widths,
nr_class=self.vocab.morphology.n_tags,
nr_feat=self.model.nr_feat)
strings = [_pad(tok.text, self.model.chars_per_word) for tok in tokens]
strings = [tok.text for tok in tokens]
for i in range(tokens.length):
eg.reset()
if tokens.c[i].pos == 0:
self.model.set_featuresC(&eg.c, tokens.c, strings, i)
self.model.predict_example(eg)
#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.vocab.morphology.assign_tag(&tokens.c[i], guess)
tokens.is_tagged = True
@ -345,7 +337,7 @@ cdef class Tagger:
"gold tags, to maintain coarse-grained mapping.")
raise ValueError(msg % tag)
golds = [self.tag_names.index(g) if g is not None else -1 for g in gold_tag_strs]
strings = [_pad(tok.text, self.model.chars_per_word) for tok in tokens]
strings = [tok.text for tok in tokens]
cdef int correct = 0
cdef Pool mem = Pool()
cdef Example eg = Example(
@ -357,16 +349,35 @@ cdef class Tagger:
eg.reset()
self.model.set_featuresC(&eg.c, tokens.c, strings, i)
eg.costs = [golds[i] not in (j, -1) for j in range(eg.c.nr_class)]
self.model.train_example(eg)
#self.model.set_scoresC(eg.c.scores,
# eg.c.features, eg.c.nr_feat)
#
#self.model.updateC(&eg.c)
self.vocab.morphology.assign_tag(&tokens.c[i], eg.guess)
correct += eg.cost == 0
self.freqs[TAG][tokens.c[i].tag] += 1
tokens.is_tagged = True
tokens._py_tokens = [None] * tokens.length
return correct
@cython.cdivision(True)
cdef int set_character_features(FeatureC* feat, unicode string, int chars_per_word) except -1:
cdef unicode oov = ''
cdef int chars_per_side = min(chars_per_word / 2, len(string))
# Fill from start
cdef int c
for c in range(chars_per_side):
feat.key = ord(string[c])
feat.value = 1.0
feat += 1
# If word is too short, zero this part of the array
for c in range(chars_per_side, chars_per_word - chars_per_side):
feat.key = 0
feat.value = 0
feat += 1
# Fill suffix
for c in range(chars_per_side):
feat.key = ord(string[-(c+1)])
feat.value = 1.0
feat += 1