def train(dataset, val_dataset, v, start_epoch=0):
"""Train the model, evaluate it and store it.
Args:
dataset (dataset.PairDataset): The training dataset.
val_dataset (dataset.PairDataset): The evaluation dataset.
v (vocab.Vocab): The vocabulary built from the training dataset.
start_epoch (int, optional): The starting epoch number. Defaults to 0.
"""
DEVICE = torch.device("cuda" if config.is_cuda else "cpu")
model = PGN(v)
model.load_model()
model.to(DEVICE)
if config.fine_tune:
# In fine-tuning mode, we fix the weights of all parameters except attention.wc.
print('Fine-tuning mode.')
for name, params in model.named_parameters():
if name != 'attention.wc.weight':
params.requires_grad = False
# forward
print("loading data")
train_data = SampleDataset(dataset.pairs, v)
val_data = SampleDataset(val_dataset.pairs, v)
print("initializing optimizer")
# Define the optimizer.
optimizer = optim.Adam(model.parameters(), lr=config.learning_rate)
train_dataloader = DataLoader(dataset=train_data,
batch_size=config.batch_size,
shuffle=True,
collate_fn=collate_fn)
val_losses = np.inf
if (os.path.exists(config.losses_path)):
with open(config.losses_path, 'rb') as f:
val_losses = pickle.load(f)
# torch.cuda.empty_cache()
# SummaryWriter: Log writer used for TensorboardX visualization.
writer = SummaryWriter(config.log_path)
# tqdm: A tool for drawing progress bars during training.
# scheduled_sampler : A tool for choosing teacher_forcing or not
num_epochs = len(range(start_epoch, config.epochs))
scheduled_sampler = ScheduledSampler(num_epochs)
if config.scheduled_sampling:
print('scheduled_sampling mode.')
# teacher_forcing = True
with tqdm(total=config.epochs) as epoch_progress:
for epoch in range(start_epoch, config.epochs):
print(config_info(config))
batch_losses = [] # Get loss of each batch.
num_batches = len(train_dataloader)
# set a teacher_forcing signal
if config.scheduled_sampling:
teacher_forcing = scheduled_sampler.teacher_forcing(
epoch - start_epoch)
else:
teacher_forcing = True
print('teacher_forcing = {}'.format(teacher_forcing))
with tqdm(total=num_batches) as batch_progress:
for batch, data in enumerate(tqdm(train_dataloader)):
x, y, x_len, y_len, oov, len_oovs = data
assert not np.any(np.isnan(x.numpy()))
if config.is_cuda: # Training with GPUs.
x = x.to(DEVICE)
y = y.to(DEVICE)
x_len = x_len.to(DEVICE)
len_oovs = len_oovs.to(DEVICE)
model.train() # Sets the module in training mode.
optimizer.zero_grad() # Clear gradients.
# Calculate loss. Call model forward propagation
loss = model(x,
x_len,
y,
len_oovs,
batch=batch,
num_batches=num_batches,
teacher_forcing=teacher_forcing)
batch_losses.append(loss.item())
loss.backward() # Backpropagation.
# Do gradient clipping to prevent gradient explosion.
clip_grad_norm_(model.encoder.parameters(),
config.max_grad_norm)
clip_grad_norm_(model.decoder.parameters(),
config.max_grad_norm)
clip_grad_norm_(model.attention.parameters(),
config.max_grad_norm)
optimizer.step() # Update weights.
# Output and record epoch loss every 100 batches.
if (batch % 32) == 0:
batch_progress.set_description(f'Epoch {epoch}')
batch_progress.set_postfix(Batch=batch,
Loss=loss.item())
batch_progress.update()
# Write loss for tensorboard.
writer.add_scalar(f'Average loss for epoch {epoch}',
np.mean(batch_losses),
global_step=batch)
# Calculate average loss over all batches in an epoch.
epoch_loss = np.mean(batch_losses)
epoch_progress.set_description(f'Epoch {epoch}')
epoch_progress.set_postfix(Loss=epoch_loss)
epoch_progress.update()
avg_val_loss = evaluate(model, val_data, epoch)
print('training loss:{}'.format(epoch_loss),
'validation loss:{}'.format(avg_val_loss))
# Update minimum evaluating loss.
if (avg_val_loss < val_losses):
torch.save(model.encoder, config.encoder_save_name)
torch.save(model.decoder, config.decoder_save_name)
torch.save(model.attention, config.attention_save_name)
torch.save(model.reduce_state, config.reduce_state_save_name)
val_losses = avg_val_loss
with open(config.losses_path, 'wb') as f:
pickle.dump(val_losses, f)
writer.close()
def train(dataset, val_dataset, v, start_epoch=0):
"""Train the model, evaluate it and store it.
Args:
dataset (dataset.PairDataset): The training dataset.
val_dataset (dataset.PairDataset): The evaluation dataset.
v (vocab.Vocab): The vocabulary built from the training dataset.
start_epoch (int, optional): The starting epoch number. Defaults to 0.
"""
torch.autograd.set_detect_anomaly(True)
DEVICE = torch.device("cuda" if config.is_cuda else "cpu")
model = PGN(v)
model.load_model()
model.to(DEVICE)
if config.fine_tune:
# In fine-tuning mode, we fix the weights of all parameters except attention.wc.
logging.info('Fine-tuning mode.')
for name, params in model.named_parameters():
if name != 'attention.wc.weight':
params.requires_grad = False
# forward
logging.info("loading data")
train_data = dataset
val_data = val_dataset
logging.info("initializing optimizer")
# Define the optimizer.
# optimizer = optim.Adam(model.parameters(), lr=config.learning_rate)
optimizer = optim.Adagrad(
model.parameters(),
lr=config.learning_rate,
initial_accumulator_value=config.initial_accumulator_value)
scheduler = StepLR(optimizer, step_size=10, gamma=0.2) # 学习率调整
train_dataloader = DataLoader(dataset=train_data,
batch_size=config.batch_size,
shuffle=True,
collate_fn=collate_fn)
val_loss = np.inf
if (os.path.exists(config.losses_path)):
with open(config.losses_path, 'r') as f:
val_loss = float(f.readlines()[-1].split("=")[-1])
logging.info("the last best val loss is: " + str(val_loss))
# torch.cuda.empty_cache()
# SummaryWriter: Log writer used for TensorboardX visualization.
writer = SummaryWriter(config.log_path)
# tqdm: A tool for drawing progress bars during training.
early_stopping_count = 0
logging.info("start training model {}, ".format(config.model_name) + \
"epoch : {}, ".format(config.epochs) +
"batch_size : {}, ".format(config.batch_size) +
"num batches: {}, ".format(len(train_dataloader)))
for epoch in range(start_epoch, config.epochs):
batch_losses = [] # Get loss of each batch.
num_batches = len(train_dataloader)
# with tqdm(total=num_batches//100) as batch_progress:
for batch, data in enumerate(train_dataloader):
x, y, x_len, y_len, oov, len_oovs, img_vec = data
assert not np.any(np.isnan(x.numpy()))
if config.is_cuda: # Training with GPUs.
x = x.to(DEVICE)
y = y.to(DEVICE)
x_len = x_len.to(DEVICE)
len_oovs = len_oovs.to(DEVICE)
img_vec = img_vec.to(DEVICE)
if batch == 0:
logging.info("x: %s, shape: %s" % (x, x.shape))
logging.info("y: %s, shape: %s" % (y, y.shape))
logging.info("oov: %s" % oov)
logging.info("img_vec: %s, shape: %s" %
(img_vec, img_vec.shape))
model.train() # Sets the module in training mode.
optimizer.zero_grad() # Clear gradients.
loss = model(x,
y,
len_oovs,
img_vec,
batch=batch,
num_batches=num_batches)
batch_losses.append(loss.item())
loss.backward() # Backpropagation.
# Do gradient clipping to prevent gradient explosion.
clip_grad_norm_(model.encoder.parameters(), config.max_grad_norm)
clip_grad_norm_(model.decoder.parameters(), config.max_grad_norm)
clip_grad_norm_(model.attention.parameters(), config.max_grad_norm)
clip_grad_norm_(model.reduce_state.parameters(),
config.max_grad_norm)
optimizer.step() # Update weights.
# scheduler.step()
# # Output and record epoch loss every 100 batches.
if (batch % 100) == 0:
# batch_progress.set_description(f'Epoch {epoch}')
# batch_progress.set_postfix(Batch=batch,
# Loss=loss.item())
# batch_progress.update()
# # Write loss for tensorboard.
writer.add_scalar(f'Average_loss_for_epoch_{epoch}',
np.mean(batch_losses),
global_step=batch)
logging.info('epoch: {}, batch:{}, training loss:{}'.format(
epoch, batch, np.mean(batch_losses)))
# Calculate average loss over all batches in an epoch.
epoch_loss = np.mean(batch_losses)
# epoch_progress.set_description(f'Epoch {epoch}')
# epoch_progress.set_postfix(Loss=epoch_loss)
# epoch_progress.update()
avg_val_loss = evaluate(model, val_data, epoch)
logging.info('epoch: {} '.format(epoch) +
'training loss:{} '.format(epoch_loss) +
'validation loss:{} '.format(avg_val_loss))
# Update minimum evaluating loss.
if not os.path.exists(os.path.dirname(config.encoder_save_name)):
os.mkdir(os.path.dirname(config.encoder_save_name))
if (avg_val_loss < val_loss):
logging.info("saving model to ../saved_model/ %s" %
config.model_name)
torch.save(model.encoder, config.encoder_save_name)
torch.save(model.decoder, config.decoder_save_name)
torch.save(model.attention, config.attention_save_name)
torch.save(model.reduce_state, config.reduce_state_save_name)
val_loss = avg_val_loss
with open(config.losses_path, 'a') as f:
f.write(f"best val loss={val_loss}\n")
else:
early_stopping_count += 1
if early_stopping_count >= config.patience:
logging.info(
f'Validation loss did not decrease for {config.patience} epochs, stop training.'
)
break
writer.close()
