def train(self,
base_path: str,
learning_rate: float = 0.1,
mini_batch_size: int = 32,
max_epochs: int = 50,
anneal_factor: float = 0.5,
patience: int = 5,
train_with_dev: bool = False,
embeddings_in_memory: bool = False,
checkpoint: bool = False,
save_final_model: bool = True,
anneal_with_restarts: bool = False,
eval_on_train: bool = True):
"""
Trains a text classification model using the training data of the corpus.
:param base_path: the directory to which any results should be written to
:param learning_rate: the learning rate
:param mini_batch_size: the mini batch size
:param max_epochs: the maximum number of epochs to train
:param anneal_factor: learning rate will be decreased by this factor
:param patience: number of 'bad' epochs before learning rate gets decreased
:param train_with_dev: boolean indicating, if the dev data set should be used for training or not
:param embeddings_in_memory: boolean indicating, if embeddings should be kept in memory or not
:param checkpoint: boolean indicating, whether the model should be save after every epoch or not
:param save_final_model: boolean indicating, whether the final model should be saved or not
:param anneal_with_restarts: boolean indicating, whether the best model should be reloaded once the learning
rate changed or not
:param eval_on_train: boolean value indicating, if evaluation metrics should be calculated on training data set
or not
"""
loss_txt = init_output_file(base_path, 'loss.tsv')
with open(loss_txt, 'a') as f:
f.write(
'EPOCH\tTIMESTAMP\tTRAIN_LOSS\t{}\tDEV_LOSS\t{}\tTEST_LOSS\t{}\n'
.format(Metric.tsv_header('TRAIN'), Metric.tsv_header('DEV'),
Metric.tsv_header('TEST')))
weight_extractor = WeightExtractor(base_path)
optimizer = torch.optim.SGD(self.model.parameters(), lr=learning_rate)
anneal_mode = 'min' if train_with_dev else 'max'
scheduler: ReduceLROnPlateau = ReduceLROnPlateau(optimizer,
factor=anneal_factor,
patience=patience,
mode=anneal_mode)
train_data = self.corpus.train
# if training also uses dev data, include in training set
if train_with_dev:
train_data.extend(self.corpus.dev)
# At any point you can hit Ctrl + C to break out of training early.
try:
previous_learning_rate = learning_rate
for epoch in range(max_epochs):
log.info('-' * 100)
bad_epochs = scheduler.num_bad_epochs
for group in optimizer.param_groups:
learning_rate = group['lr']
# reload last best model if annealing with restarts is enabled
if learning_rate != previous_learning_rate and anneal_with_restarts and \
os.path.exists(base_path + "/best-model.pt"):
log.info('Resetting to best model ...')
self.model.load_from_file(base_path + "/best-model.pt")
previous_learning_rate = learning_rate
# stop training if learning rate becomes too small
if learning_rate < 0.001:
log.info('Learning rate too small - quitting training!')
break
if not self.test_mode:
random.shuffle(train_data)
self.model.train()
batches = [
self.corpus.train[x:x + mini_batch_size]
for x in range(0, len(self.corpus.train), mini_batch_size)
]
current_loss: float = 0
seen_sentences = 0
modulo = max(1, int(len(batches) / 10))
for batch_no, batch in enumerate(batches):
scores = self.model.forward(batch)
loss = self.model.calculate_loss(scores, batch)
optimizer.zero_grad()
loss.backward()
torch.nn.utils.clip_grad_norm_(self.model.parameters(),
5.0)
optimizer.step()
seen_sentences += len(batch)
current_loss += loss.item()
clear_embeddings(
batch,
also_clear_word_embeddings=not embeddings_in_memory)
if batch_no % modulo == 0:
log.info(
"epoch {0} - iter {1}/{2} - loss {3:.8f}".format(
epoch + 1, batch_no, len(batches),
current_loss / seen_sentences))
iteration = epoch * len(batches) + batch_no
weight_extractor.extract_weights(
self.model.state_dict(), iteration)
current_loss /= len(train_data)
self.model.eval()
# if checkpoint is enable, save model at each epoch
if checkpoint:
self.model.save(base_path + "/checkpoint.pt")
log.info('-' * 100)
log.info("EPOCH {0}: lr {1:.4f} - bad epochs {2}".format(
epoch + 1, learning_rate, bad_epochs))
dev_metric = train_metric = None
dev_loss = '_'
train_loss = current_loss
if eval_on_train:
train_metric, train_loss = self._calculate_evaluation_results_for(
'TRAIN', self.corpus.train, embeddings_in_memory,
mini_batch_size)
if not train_with_dev:
dev_metric, dev_loss = self._calculate_evaluation_results_for(
'DEV', self.corpus.dev, embeddings_in_memory,
mini_batch_size)
with open(loss_txt, 'a') as f:
train_metric_str = train_metric.to_tsv(
) if train_metric is not None else Metric.to_empty_tsv()
dev_metric_str = dev_metric.to_tsv(
) if dev_metric is not None else Metric.to_empty_tsv()
f.write('{}\t{:%H:%M:%S}\t{}\t{}\t{}\t{}\t{}\t{}\n'.format(
epoch, datetime.datetime.now(), train_loss,
train_metric_str, dev_loss, dev_metric_str, '_',
Metric.to_empty_tsv()))
# anneal against train loss if training with dev, otherwise anneal against dev score
scheduler.step(
current_loss) if train_with_dev else scheduler.step(
dev_metric.f_score())
current_score = dev_metric.f_score(
) if not train_with_dev else train_metric.f_score()
# if we use dev data, remember best model based on dev evaluation score
if not train_with_dev and current_score == scheduler.best:
self.model.save(base_path + "/best-model.pt")
if save_final_model:
self.model.save(base_path + "/final-model.pt")
log.info('-' * 100)
log.info('Testing using best model ...')
self.model.eval()
if os.path.exists(base_path + "/best-model.pt"):
self.model = TextClassifier.load_from_file(base_path +
"/best-model.pt")
test_metric, test_loss = self.evaluate(
self.corpus.test,
mini_batch_size=mini_batch_size,
eval_class_metrics=True,
embeddings_in_memory=embeddings_in_memory,
metric_name='TEST')
test_metric.print()
self.model.train()
log.info('-' * 100)
except KeyboardInterrupt:
log.info('-' * 100)
log.info('Exiting from training early.')
log.info('Saving model ...')
with open(base_path + "/final-model.pt", 'wb') as model_save_file:
torch.save(self.model, model_save_file, pickle_protocol=4)
model_save_file.close()
log.info('Done.')
def train(
self,
base_path: str,
learning_rate: float = 0.1,
mini_batch_size: int = 32,
max_epochs: int = 100,
anneal_factor: float = 0.5,
patience: int = 4,
train_with_dev: bool = False,
embeddings_in_memory: bool = True,
checkpoint: bool = False,
save_final_model: bool = True,
anneal_with_restarts: bool = False,
):
evaluation_method = 'F1'
if self.model.tag_type in ['pos', 'upos']:
evaluation_method = 'accuracy'
log.info('Evaluation method: {}'.format(evaluation_method))
loss_txt = init_output_file(base_path, 'loss.tsv')
with open(loss_txt, 'a') as f:
f.write(
'EPOCH\tTIMESTAMP\tTRAIN_LOSS\t{}\tDEV_LOSS\t{}\tTEST_LOSS\t{}\n'
.format(Metric.tsv_header('TRAIN'), Metric.tsv_header('DEV'),
Metric.tsv_header('TEST')))
weight_extractor = WeightExtractor(base_path)
optimizer = torch.optim.SGD(self.model.parameters(), lr=learning_rate)
# annealing scheduler
anneal_mode = 'min' if train_with_dev else 'max'
scheduler = ReduceLROnPlateau(optimizer,
factor=anneal_factor,
patience=patience,
mode=anneal_mode,
verbose=True)
train_data = self.corpus.train
# if training also uses dev data, include in training set
if train_with_dev:
train_data.extend(self.corpus.dev)
# At any point you can hit Ctrl + C to break out of training early.
try:
previous_learning_rate = learning_rate
for epoch in range(0, max_epochs):
log.info('-' * 100)
bad_epochs = scheduler.num_bad_epochs
for group in optimizer.param_groups:
learning_rate = group['lr']
# reload last best model if annealing with restarts is enabled
if learning_rate != previous_learning_rate and anneal_with_restarts and \
os.path.exists(base_path + "/best-model.pt"):
log.info('resetting to best model')
self.model.load_from_file(base_path + "/best-model.pt")
previous_learning_rate = learning_rate
# stop training if learning rate becomes too small
if learning_rate < 0.001:
log.info('learning rate too small - quitting training!')
break
if not self.test_mode:
random.shuffle(train_data)
batches = [
train_data[x:x + mini_batch_size]
for x in range(0, len(train_data), mini_batch_size)
]
self.model.train()
current_loss: float = 0
seen_sentences = 0
modulo = max(1, int(len(batches) / 10))
for batch_no, batch in enumerate(batches):
batch: List[Sentence] = batch
optimizer.zero_grad()
# Step 4. Compute the loss, gradients, and update the parameters by calling optimizer.step()
loss = self.model.neg_log_likelihood(batch)
current_loss += loss.item()
seen_sentences += len(batch)
loss.backward()
torch.nn.utils.clip_grad_norm_(self.model.parameters(),
5.0)
optimizer.step()
if not embeddings_in_memory:
self.clear_embeddings_in_batch(batch)
if batch_no % modulo == 0:
log.info(
"epoch {0} - iter {1}/{2} - loss {3:.8f}".format(
epoch + 1, batch_no, len(batches),
current_loss / seen_sentences))
iteration = epoch * len(batches) + batch_no
weight_extractor.extract_weights(
self.model.state_dict(), iteration)
current_loss /= len(train_data)
# switch to eval mode
self.model.eval()
# if checkpointing is enable, save model at each epoch
if checkpoint:
self.model.save(base_path + "/checkpoint.pt")
log.info('-' * 100)
dev_score = dev_metric = None
if not train_with_dev:
dev_score, dev_metric = self.evaluate(
self.corpus.dev,
base_path,
evaluation_method=evaluation_method,
embeddings_in_memory=embeddings_in_memory)
test_score, test_metric = self.evaluate(
self.corpus.test,
base_path,
evaluation_method=evaluation_method,
embeddings_in_memory=embeddings_in_memory)
# anneal against train loss if training with dev, otherwise anneal against dev score
scheduler.step(
current_loss) if train_with_dev else scheduler.step(
dev_score)
# logging info
log.info("EPOCH {0}: lr {1:.4f} - bad epochs {2}".format(
epoch + 1, learning_rate, bad_epochs))
if not train_with_dev:
log.info(
"{0:<4}: f-score {1:.4f} - acc {2:.4f} - tp {3} - fp {4} - fn {5} - tn {6}"
.format('DEV', dev_metric.f_score(),
dev_metric.accuracy(), dev_metric._tp,
dev_metric._fp, dev_metric._fn,
dev_metric._tn))
log.info(
"{0:<4}: f-score {1:.4f} - acc {2:.4f} - tp {3} - fp {4} - fn {5} - tn {6}"
.format('TEST', test_metric.f_score(),
test_metric.accuracy(), test_metric._tp,
test_metric._fp, test_metric._fn, test_metric._tn))
with open(loss_txt, 'a') as f:
dev_metric_str = dev_metric.to_tsv(
) if dev_metric is not None else Metric.to_empty_tsv()
f.write('{}\t{:%H:%M:%S}\t{}\t{}\t{}\t{}\t{}\t{}\n'.format(
epoch, datetime.datetime.now(), '_',
Metric.to_empty_tsv(), '_', dev_metric_str, '_',
test_metric.to_tsv()))
# if we use dev data, remember best model based on dev evaluation score
if not train_with_dev and dev_score == scheduler.best:
self.model.save(base_path + "/best-model.pt")
# if we do not use dev data for model selection, save final model
if save_final_model:
self.model.save(base_path + "/final-model.pt")
except KeyboardInterrupt:
log.info('-' * 100)
log.info('Exiting from training early.')
log.info('Saving model ...')
self.model.save(base_path + "/final-model.pt")
log.info('Done.')
from __future__ import absolute_import
