spaCy/examples/pipeline/wiki_entity_linking/train_descriptions.py

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from random import shuffle
from examples.pipeline.wiki_entity_linking import kb_creator
import numpy as np
from spacy._ml import zero_init, create_default_optimizer
from spacy.cli.pretrain import get_cossim_loss
from thinc.v2v import Model
from thinc.api import chain
from thinc.neural._classes.affine import Affine
class EntityEncoder:
INPUT_DIM = 300 # dimension of pre-trained vectors
DESC_WIDTH = 64
DROP = 0
EPOCHS = 5
STOP_THRESHOLD = 0.05
BATCH_SIZE = 1000
def __init__(self, kb, nlp):
self.nlp = nlp
self.kb = kb
def run(self, entity_descr_output):
id_to_descr = kb_creator._get_id_to_description(entity_descr_output)
processed, loss = self._train_model(entity_descr_output, id_to_descr)
print("Trained on", processed, "entities across", self.EPOCHS, "epochs")
print("Final loss:", loss)
print()
# TODO: apply and write to file afterwards !
# self._apply_encoder(id_to_descr)
def _train_model(self, entity_descr_output, id_to_descr):
# TODO: when loss gets too low, a 'mean of empty slice' warning is thrown by numpy
self._build_network(self.INPUT_DIM, self.DESC_WIDTH)
processed = 0
loss = 1
for i in range(self.EPOCHS):
entity_keys = list(id_to_descr.keys())
shuffle(entity_keys)
batch_nr = 0
start = 0
stop = min(self.BATCH_SIZE, len(entity_keys))
while loss > self.STOP_THRESHOLD and start < len(entity_keys):
batch = []
for e in entity_keys[start:stop]:
descr = id_to_descr[e]
doc = self.nlp(descr)
doc_vector = self._get_doc_embedding(doc)
batch.append(doc_vector)
loss = self.update(batch)
print(i, batch_nr, loss)
processed += len(batch)
batch_nr += 1
start = start + self.BATCH_SIZE
stop = min(stop + self.BATCH_SIZE, len(entity_keys))
return processed, loss
def _apply_encoder(self, id_to_descr):
for id, descr in id_to_descr.items():
doc = self.nlp(descr)
doc_vector = self._get_doc_embedding(doc)
encoding = self.encoder(np.asarray([doc_vector]))
@staticmethod
def _get_doc_embedding(doc):
indices = np.zeros((len(doc),), dtype="i")
for i, word in enumerate(doc):
if word.orth in doc.vocab.vectors.key2row:
indices[i] = doc.vocab.vectors.key2row[word.orth]
else:
indices[i] = 0
word_vectors = doc.vocab.vectors.data[indices]
doc_vector = np.mean(word_vectors, axis=0) # TODO: min? max?
return doc_vector
def _build_network(self, orig_width, hidden_with):
with Model.define_operators({">>": chain}):
self.encoder = (
Affine(hidden_with, orig_width)
)
self.model = self.encoder >> zero_init(Affine(orig_width, hidden_with, drop_factor=0.0))
self.sgd = create_default_optimizer(self.model.ops)
def update(self, vectors):
predictions, bp_model = self.model.begin_update(np.asarray(vectors), drop=self.DROP)
loss, d_scores = self.get_loss(scores=predictions, golds=np.asarray(vectors))
bp_model(d_scores, sgd=self.sgd)
return loss / len(vectors)
@staticmethod
def get_loss(golds, scores):
loss, gradients = get_cossim_loss(scores, golds)
return loss, gradients