gFun/refactor/models/pl_bert.py

185 lines
9.7 KiB
Python

import torch
import pytorch_lightning as pl
from torch.optim.lr_scheduler import StepLR
from transformers import BertForSequenceClassification, AdamW
from util.pl_metrics import CustomF1, CustomK
from util.common import define_pad_length, pad
class BertModel(pl.LightningModule):
def __init__(self, output_size, stored_path, gpus=None):
"""
Init Bert model.
:param output_size:
:param stored_path:
:param gpus:
"""
super().__init__()
self.loss = torch.nn.BCEWithLogitsLoss()
self.gpus = gpus
self.microF1 = CustomF1(num_classes=output_size, average='micro', device=self.gpus)
self.macroF1 = CustomF1(num_classes=output_size, average='macro', device=self.gpus)
self.microK = CustomK(num_classes=output_size, average='micro', device=self.gpus)
self.macroK = CustomK(num_classes=output_size, average='macro', device=self.gpus)
# Language specific metrics - I am not really sure if they should be initialized
# independently or we can use the metrics init above... # TODO: check it
self.lang_macroF1 = CustomF1(num_classes=output_size, average='macro', device=self.gpus)
self.lang_microF1 = CustomF1(num_classes=output_size, average='micro', device=self.gpus)
self.lang_macroK = CustomF1(num_classes=output_size, average='macro', device=self.gpus)
self.lang_microK = CustomF1(num_classes=output_size, average='micro', device=self.gpus)
if stored_path:
self.bert = BertForSequenceClassification.from_pretrained(stored_path,
num_labels=output_size,
output_hidden_states=True)
else:
self.bert = BertForSequenceClassification.from_pretrained('bert-base-multilingual-cased',
num_labels=output_size,
output_hidden_states=True)
self.save_hyperparameters()
def forward(self, X):
logits = self.bert(X)
return logits
def training_step(self, train_batch, batch_idx):
X, y, _, batch_langs = train_batch
X = torch.cat(X).view([X[0].shape[0], len(X)])
y = y.type(torch.FloatTensor)
y = y.to('cuda' if self.gpus else 'cpu')
logits, _ = self.forward(X)
loss = self.loss(logits, y)
# Squashing logits through Sigmoid in order to get confidence score
predictions = torch.sigmoid(logits) > 0.5
microF1 = self.microF1(predictions, y)
macroF1 = self.macroF1(predictions, y)
microK = self.microK(predictions, y)
macroK = self.macroK(predictions, y)
self.log('train-loss', loss, on_step=True, on_epoch=True, prog_bar=False, logger=True)
self.log('train-macroF1', macroF1, on_step=True, on_epoch=True, prog_bar=False, logger=True)
self.log('train-microF1', microF1, on_step=True, on_epoch=True, prog_bar=False, logger=True)
self.log('train-macroK', macroK, on_step=True, on_epoch=True, prog_bar=False, logger=True)
self.log('train-microK', microK, on_step=True, on_epoch=True, prog_bar=False, logger=True)
lX, ly = self._reconstruct_dict(predictions, y, batch_langs)
return {'loss': loss, 'pred': lX, 'target': ly}
def training_epoch_end(self, outputs):
langs = []
for output in outputs:
langs.extend(list(output['pred'].keys()))
langs = set(langs)
# outputs is a of n dicts of m elements, where n is equal to the number of epoch steps and m is batchsize.
# here we save epoch level metric values and compute them specifically for each language
# TODO: make this a function (reused in pl_gru epoch_end)
res_macroF1 = {lang: [] for lang in langs}
res_microF1 = {lang: [] for lang in langs}
res_macroK = {lang: [] for lang in langs}
res_microK = {lang: [] for lang in langs}
for output in outputs:
lX, ly = output['pred'], output['target']
for lang in lX.keys():
X, y = lX[lang], ly[lang]
lang_macroF1 = self.lang_macroF1(X, y)
lang_microF1 = self.lang_microF1(X, y)
lang_macroK = self.lang_macroK(X, y)
lang_microK = self.lang_microK(X, y)
res_macroF1[lang].append(lang_macroF1)
res_microF1[lang].append(lang_microF1)
res_macroK[lang].append(lang_macroK)
res_microK[lang].append(lang_microK)
for lang in langs:
avg_macroF1 = torch.mean(torch.Tensor(res_macroF1[lang]))
avg_microF1 = torch.mean(torch.Tensor(res_microF1[lang]))
avg_macroK = torch.mean(torch.Tensor(res_macroK[lang]))
avg_microK = torch.mean(torch.Tensor(res_microK[lang]))
self.logger.experiment.add_scalars('train-langs-macroF1', {f'{lang}': avg_macroF1}, self.current_epoch)
self.logger.experiment.add_scalars('train-langs-microF1', {f'{lang}': avg_microF1}, self.current_epoch)
self.logger.experiment.add_scalars('train-langs-macroK', {f'{lang}': avg_macroK}, self.current_epoch)
self.logger.experiment.add_scalars('train-langs-microK', {f'{lang}': avg_microK}, self.current_epoch)
def validation_step(self, val_batch, batch_idx):
X, y, _, batch_langs = val_batch
X = torch.cat(X).view([X[0].shape[0], len(X)])
y = y.type(torch.FloatTensor)
y = y.to('cuda' if self.gpus else 'cpu')
logits, _ = self.forward(X)
loss = self.loss(logits, y)
predictions = torch.sigmoid(logits) > 0.5
microF1 = self.microF1(predictions, y)
macroF1 = self.macroF1(predictions, y)
microK = self.microK(predictions, y)
macroK = self.macroK(predictions, y)
self.log('val-loss', loss, on_step=False, on_epoch=True, prog_bar=False, logger=True)
self.log('val-macroF1', macroF1, on_step=False, on_epoch=True, prog_bar=True, logger=True)
self.log('val-microF1', microF1, on_step=False, on_epoch=True, prog_bar=True, logger=True)
self.log('val-macroK', macroK, on_step=False, on_epoch=True, prog_bar=True, logger=True)
self.log('val-microK', microK, on_step=False, on_epoch=True, prog_bar=True, logger=True)
return {'loss': loss}
def test_step(self, test_batch, batch_idx):
X, y, _, batch_langs = test_batch
X = torch.cat(X).view([X[0].shape[0], len(X)])
y = y.type(torch.FloatTensor)
y = y.to('cuda' if self.gpus else 'cpu')
logits, _ = self.forward(X)
loss = self.loss(logits, y)
# Squashing logits through Sigmoid in order to get confidence score
predictions = torch.sigmoid(logits) > 0.5
microF1 = self.microF1(predictions, y)
macroF1 = self.macroF1(predictions, y)
microK = self.microK(predictions, y)
macroK = self.macroK(predictions, y)
self.log('test-macroF1', macroF1, on_step=False, on_epoch=True, prog_bar=False, logger=True)
self.log('test-microF1', microF1, on_step=False, on_epoch=True, prog_bar=False, logger=True)
self.log('test-macroK', macroK, on_step=False, on_epoch=True, prog_bar=True, logger=True)
self.log('test-microK', microK, on_step=False, on_epoch=True, prog_bar=True, logger=True)
return
def configure_optimizers(self, lr=3e-5, weight_decay=0.01):
no_decay = ['bias', 'LayerNorm.weight']
optimizer_grouped_parameters = [
{'params': [p for n, p in self.bert.named_parameters()
if not any(nd in n for nd in no_decay)],
'weight_decay': weight_decay},
{'params': [p for n, p in self.bert.named_parameters()
if any(nd in n for nd in no_decay)],
'weight_decay': weight_decay}
]
optimizer = AdamW(optimizer_grouped_parameters, lr=lr)
scheduler = StepLR(optimizer, step_size=25, gamma=0.1)
return [optimizer], [scheduler]
def encode(self, lX, batch_size=64):
with torch.no_grad():
l_embed = {lang: [] for lang in lX.keys()}
for lang in sorted(lX.keys()):
for i in range(0, len(lX[lang]), batch_size):
if i + batch_size > len(lX[lang]):
batch = lX[lang][i:len(lX[lang])]
else:
batch = lX[lang][i:i + batch_size]
max_pad_len = define_pad_length(batch)
batch = pad(batch, pad_index=self.bert.config.pad_token_id, max_pad_length=max_pad_len)
batch = torch.LongTensor(batch).to('cuda' if self.gpus else 'cpu')
_, output = self.forward(batch)
doc_embeds = output[-1][:, 0, :]
l_embed[lang].append(doc_embeds.cpu())
for k, v in l_embed.items():
l_embed[k] = torch.cat(v, dim=0).numpy()
return l_embed
@staticmethod
def _reconstruct_dict(predictions, y, batch_langs):
reconstructed_x = {lang: [] for lang in set(batch_langs)}
reconstructed_y = {lang: [] for lang in set(batch_langs)}
for i, pred in enumerate(predictions):
reconstructed_x[batch_langs[i]].append(pred)
reconstructed_y[batch_langs[i]].append(y[i])
for k, v in reconstructed_x.items():
reconstructed_x[k] = torch.cat(v).view(-1, predictions.shape[1])
for k, v in reconstructed_y.items():
reconstructed_y[k] = torch.cat(v).view(-1, predictions.shape[1])
return reconstructed_x, reconstructed_y