def job_producer():
"""Fill jobs queue using the input `sentences` iterator."""
job_batch, batch_size = [], 0
pushed_words, pushed_examples = 0, 0
next_alpha = self.alpha
if next_alpha > self.min_alpha_yet_reached:
logger.warn("Effective 'alpha' higher than previous training cycles")
self.min_alpha_yet_reached = next_alpha
job_no = 0
for sent_idx, sentence in enumerate(sentences):
sentence_length = self._raw_word_count([sentence])
# can we fit this sentence into the existing job batch?
if batch_size + sentence_length <= self.batch_words:
# yes => add it to the current job
job_batch.append(sentence)
batch_size += sentence_length
else:
# no => submit the existing job
pair_idx = list(
numpy.random.choice(
range(len(self.pairwise_constraints)), int(batch_size * 0.2)))
pairwise_samples = [self.pairwise_constraints[x] for x in pair_idx]
logger.debug(
"queueing job #%i (%i words, %i sentences, %i constraints) at alpha %.05f",
job_no, batch_size, len(job_batch), len(pairwise_samples),
next_alpha)
job_no += 1
job_queue.put((job_batch, pairwise_samples, next_alpha))
# update the learning rate for the next job
if self.min_alpha < next_alpha:
if total_examples:
# examples-based decay
pushed_examples += len(job_batch)
progress = 1.0 * pushed_examples / total_examples
else:
# words-based decay
pushed_words += self._raw_word_count(job_batch)
progress = 1.0 * pushed_words / total_words
next_alpha = self.alpha - (self.alpha - self.min_alpha) * progress
next_alpha = max(self.min_alpha, next_alpha)
# add the sentence that didn't fit as the first item of a new job
job_batch, batch_size = [sentence], sentence_length
# add the last job too (may be significantly smaller than batch_words)
if job_batch:
logger.debug(
"queueing job #%i (%i words, %i sentences, %i constraints) at alpha %.05f",
job_no, batch_size, len(job_batch), len(self.pairwise_constraints),
next_alpha)
job_no += 1
job_queue.put((job_batch, self.pairwise_constraints, next_alpha))
if job_no == 0 and self.train_count == 0:
logger.warning(
"train() called with an empty iterator (if not intended, "
"be sure to provide a corpus that offers restartable "
"iteration = an iterable).")
# give the workers heads up that they can finish -- no more work!
for _ in xrange(self.workers):
job_queue.put(None)
logger.debug("job loop exiting, total %i jobs", job_no)
def train(self,
sentences,
total_words=None,
word_count=0,
total_examples=None,
queue_factor=2,
report_delay=1.0):
""" Update the model's neural weights from a sequence of sentences (can be a
once-only generator stream).
For Word2Vec, each sentence must be a list of unicode strings.
(Subclasses may accept other examples.)
To support linear learning-rate decay from (initial) alpha to min_alpha,
either total_examples
(count of sentences) or total_words (count of raw words in sentences)
should be provided, unless the
sentences are the same as those that were used to initially build the
vocabulary.
"""
logger.info("Starting training.")
self.neg_labels = []
if self.negative > 0:
# precompute negative labels optimization for pure-python training
self.neg_labels = zeros(self.negative + 1)
self.neg_labels[0] = 1.
if FAST_VERSION < 0:
import warnings
warnings.warn(
"C extension not loaded for Word2Vec, training will be slow. "
"Install a C compiler and reinstall gensim for fast training.")
self.neg_labels = []
if self.negative > 0:
# precompute negative labels optimization for pure-python training
self.neg_labels = zeros(self.negative + 1)
self.neg_labels[0] = 1.
logger.info(
"training model with %i workers on %i vocabulary and %i features, "
"using sg=%s hs=%s sample=%s negative=%s window=%s", self.workers,
len(self.vocab), self.layer1_size, self.sg, self.hs, self.sample,
self.negative, self.window)
if not self.vocab:
raise RuntimeError(
"you must first build vocabulary before training the model")
if not hasattr(self, "syn0"):
raise RuntimeError(
"you must first finalize vocabulary before training the model")
if total_words is None and total_examples is None:
if self.corpus_count:
total_examples = self.corpus_count
logger.info(
"expecting %i sentences, matching count from corpus used for vocabulary survey",
total_examples)
else:
raise ValueError(
"you must provide either total_words or total_examples, to enable alpha and progress calculations"
)
job_tally = 0
if self.iter > 1:
sentences = utils.RepeatCorpusNTimes(sentences, self.iter)
total_words = total_words and total_words * self.iter
total_examples = total_examples and total_examples * self.iter
def worker_loop():
"""Train the model, lifting lists of sentences from the job_queue."""
work = matutils.zeros_aligned(
self.layer1_size, dtype=REAL) # per-thread private work memory
neu1 = matutils.zeros_aligned(self.layer1_size, dtype=REAL)
jobs_processed = 0
while True:
job = job_queue.get()
if job is None:
progress_queue.put(None)
break # no more jobs => quit this worker
sentences, pairwise, alpha = job
tally, raw_tally = self._do_train_job(sentences, pairwise, alpha,
(work, neu1))
progress_queue.put(
(len(sentences), tally, raw_tally)) # report back progress
jobs_processed += 1
logger.debug("worker exiting, processed %i jobs", jobs_processed)
def job_producer():
"""Fill jobs queue using the input `sentences` iterator."""
job_batch, batch_size = [], 0
pushed_words, pushed_examples = 0, 0
next_alpha = self.alpha
if next_alpha > self.min_alpha_yet_reached:
logger.warn("Effective 'alpha' higher than previous training cycles")
self.min_alpha_yet_reached = next_alpha
job_no = 0
for sent_idx, sentence in enumerate(sentences):
sentence_length = self._raw_word_count([sentence])
# can we fit this sentence into the existing job batch?
if batch_size + sentence_length <= self.batch_words:
# yes => add it to the current job
job_batch.append(sentence)
batch_size += sentence_length
else:
# no => submit the existing job
pair_idx = list(
numpy.random.choice(
range(len(self.pairwise_constraints)), int(batch_size * 0.2)))
pairwise_samples = [self.pairwise_constraints[x] for x in pair_idx]
logger.debug(
"queueing job #%i (%i words, %i sentences, %i constraints) at alpha %.05f",
job_no, batch_size, len(job_batch), len(pairwise_samples),
next_alpha)
job_no += 1
job_queue.put((job_batch, pairwise_samples, next_alpha))
# update the learning rate for the next job
if self.min_alpha < next_alpha:
if total_examples:
# examples-based decay
pushed_examples += len(job_batch)
progress = 1.0 * pushed_examples / total_examples
else:
# words-based decay
pushed_words += self._raw_word_count(job_batch)
progress = 1.0 * pushed_words / total_words
next_alpha = self.alpha - (self.alpha - self.min_alpha) * progress
next_alpha = max(self.min_alpha, next_alpha)
# add the sentence that didn't fit as the first item of a new job
job_batch, batch_size = [sentence], sentence_length
# add the last job too (may be significantly smaller than batch_words)
if job_batch:
logger.debug(
"queueing job #%i (%i words, %i sentences, %i constraints) at alpha %.05f",
job_no, batch_size, len(job_batch), len(self.pairwise_constraints),
next_alpha)
job_no += 1
job_queue.put((job_batch, self.pairwise_constraints, next_alpha))
if job_no == 0 and self.train_count == 0:
logger.warning(
"train() called with an empty iterator (if not intended, "
"be sure to provide a corpus that offers restartable "
"iteration = an iterable).")
# give the workers heads up that they can finish -- no more work!
for _ in xrange(self.workers):
job_queue.put(None)
logger.debug("job loop exiting, total %i jobs", job_no)
# buffer ahead only a limited number of jobs.. this is the reason we can't simply use ThreadPool :(
job_queue = Queue(maxsize=queue_factor * self.workers)
progress_queue = Queue(maxsize=(queue_factor + 1) * self.workers)
workers = [
threading.Thread(target=worker_loop) for _ in xrange(self.workers)
]
unfinished_worker_count = len(workers)
workers.append(threading.Thread(target=job_producer))
for thread in workers:
thread.daemon = True # make interrupting the process with ctrl+c easier
thread.start()
example_count, trained_word_count, raw_word_count = 0, 0, word_count
start, next_report = default_timer() - 0.00001, 1.0
while unfinished_worker_count > 0:
report = progress_queue.get() # blocks if workers too slow
if report is None: # a thread reporting that it finished
unfinished_worker_count -= 1
logger.info(
"worker thread finished; awaiting finish of %i more threads",
unfinished_worker_count)
continue
examples, trained_words, raw_words = report
job_tally += 1
# update progress stats
example_count += examples
trained_word_count += trained_words # only words in vocab & sampled
raw_word_count += raw_words
# log progress once every report_delay seconds
elapsed = default_timer() - start
if elapsed >= next_report:
if total_examples:
# examples-based progress %
logger.info(
"PROGRESS: at %.2f%% examples, %.0f words/s, in_qsize %i, out_qsize %i",
100.0 * example_count / total_examples,
trained_word_count / elapsed, utils.qsize(job_queue),
utils.qsize(progress_queue))
else:
# words-based progress %
logger.info(
"PROGRESS: at %.2f%% words, %.0f words/s, in_qsize %i, out_qsize %i",
100.0 * raw_word_count / total_words,
trained_word_count / elapsed, utils.qsize(job_queue),
utils.qsize(progress_queue))
next_report = elapsed + report_delay
# all done; report the final stats
elapsed = default_timer() - start
logger.info(
"training on %i raw words (%i effective words) took %.1fs, %.0f effective words/s",
raw_word_count, trained_word_count, elapsed,
trained_word_count / elapsed)
if job_tally < 10 * self.workers:
logger.warn(
"under 10 jobs per worker: consider setting a smaller `batch_words' for smoother alpha decay"
)
# check that the input corpus hasn't changed during iteration
if total_examples and total_examples != example_count:
logger.warn(
"supplied example count (%i) did not equal expected count (%i)",
example_count, total_examples)
if total_words and total_words != raw_word_count:
logger.warn(
"supplied raw word count (%i) did not equal expected count (%i)",
raw_word_count, total_words)
self.train_count += 1 # number of times train() has been called
self.total_train_time += elapsed
self.clear_sims()
return trained_word_count