gfun_multimodal/gfun/vgfs/transformerGen.py

389 lines
13 KiB
Python

import os
os.environ["TOKENIZERS_PARALLELISM"] = "true"
from collections import defaultdict
import numpy as np
import torch
import transformers
from sklearn.model_selection import train_test_split
from torch.optim import AdamW
from torch.utils.data import DataLoader, Dataset
from transformers import AutoModelForSequenceClassification, AutoTokenizer
from vgfs.learners.svms import FeatureSet2Posteriors
from evaluation.evaluate import evaluate, log_eval
transformers.logging.set_verbosity_error()
# TODO: add support to loggers
class TransformerGen:
def __init__(
self,
model_name,
epochs=10,
lr=1e-5,
batch_size=4,
batch_size_eval=32,
max_length=512,
print_steps=50,
device="cpu",
probabilistic=False,
n_jobs=-1,
evaluate_step=10,
verbose=False,
patience=5,
):
self.model_name = model_name
self.device = device
self.model = None
self.lr = lr
self.epochs = epochs
self.tokenizer = None
self.max_length = max_length
self.batch_size = batch_size
self.batch_size_eval = batch_size_eval
self.print_steps = print_steps
self.probabilistic = probabilistic
self.n_jobs = n_jobs
self.fitted = False
self.datasets = {}
self.evaluate_step = evaluate_step
self.verbose = verbose
self.patience = patience
self._init()
def _init(self):
if self.probabilistic:
self.feature2posterior_projector = FeatureSet2Posteriors(
n_jobs=self.n_jobs, verbose=False
)
self.model_name = self._get_model_name(self.model_name)
print(
f"- init TransformerModel model_name: {self.model_name}, device: {self.device}]"
)
def _get_model_name(self, name):
if "bert" == name:
name_model = "bert-base-uncased"
elif "mbert" == name:
name_model = "bert-base-multilingual-uncased"
elif "xlm" == name:
name_model = "xlm-roberta-base"
else:
raise NotImplementedError
return name_model
def load_pretrained_model(self, model_name, num_labels):
return AutoModelForSequenceClassification.from_pretrained(
model_name, num_labels=num_labels, output_hidden_states=True
)
def load_tokenizer(self, model_name):
return AutoTokenizer.from_pretrained(model_name)
def init_model(self, model_name, num_labels):
return self.load_pretrained_model(model_name, num_labels), self.load_tokenizer(
model_name
)
def get_train_val_data(self, lX, lY, split=0.2, seed=42):
tr_lX, tr_lY, val_lX, val_lY = {}, {}, {}, {}
for lang in lX.keys():
tr_X, val_X, tr_Y, val_Y = train_test_split(
lX[lang], lY[lang], test_size=split, random_state=seed, shuffle=False
)
tr_lX[lang] = tr_X
tr_lY[lang] = tr_Y
val_lX[lang] = val_X
val_lY[lang] = val_Y
return tr_lX, tr_lY, val_lX, val_lY
def build_dataloader(self, lX, lY, batch_size, split="train", shuffle=True):
l_tokenized = {lang: self._tokenize(data) for lang, data in lX.items()}
self.datasets[split] = MultilingualDatasetTorch(l_tokenized, lY, split=split)
return DataLoader(self.datasets[split], batch_size=batch_size, shuffle=shuffle)
def _tokenize(self, X):
return self.tokenizer(
X,
return_tensors="pt",
padding="max_length",
truncation=True,
max_length=self.max_length,
)
def fit(self, lX, lY):
if self.fitted:
return self
print("- fitting Transformer View Generating Function")
_l = list(lX.keys())[0]
self.num_labels = lY[_l].shape[-1]
self.model, self.tokenizer = self.init_model(
self.model_name, num_labels=self.num_labels
)
tr_lX, tr_lY, val_lX, val_lY = self.get_train_val_data(
lX, lY, split=0.2, seed=42
)
tra_dataloader = self.build_dataloader(
tr_lX, tr_lY, self.batch_size, split="train", shuffle=True
)
val_dataloader = self.build_dataloader(
val_lX, val_lY, self.batch_size_eval, split="val", shuffle=False
)
experiment_name = f"{self.model_name}-{self.epochs}-{self.batch_size}"
trainer = Trainer(
model=self.model,
optimizer_name="adamW",
lr=self.lr,
device=self.device,
loss_fn=torch.nn.CrossEntropyLoss(),
print_steps=self.print_steps,
evaluate_step=self.evaluate_step,
patience=self.patience,
experiment_name=experiment_name,
)
trainer.train(
train_dataloader=tra_dataloader,
eval_dataloader=val_dataloader,
epochs=self.epochs,
)
if self.probabilistic:
self.feature2posterior_projector.fit(self.transform(lX), lY)
self.fitted = True
return self
def transform(self, lX):
_embeds = []
l_embeds = defaultdict(list)
dataloader = self.build_dataloader(
lX, lY=None, batch_size=self.batch_size_eval, split="whole", shuffle=False
)
self.model.eval()
with torch.no_grad():
for input_ids, lang in dataloader:
input_ids = input_ids.to(self.device)
out = self.model(input_ids).hidden_states[-1]
batch_embeddings = out[:, 0, :].cpu().numpy()
_embeds.append((batch_embeddings, lang))
for embed, lang in _embeds:
for sample_embed, sample_lang in zip(embed, lang):
l_embeds[sample_lang].append(sample_embed)
if self.probabilistic and self.fitted:
l_embeds = self.feature2posterior_projector.transform(l_embeds)
return l_embeds
def fit_transform(self, lX, lY):
return self.fit(lX, lY).transform(lX)
def save_vgf(self, model_id):
import pickle
from os.path import join
from os import makedirs
vgf_name = "transformerGen"
_basedir = join("models", "vgfs", "transformer")
makedirs(_basedir, exist_ok=True)
_path = join(_basedir, f"{vgf_name}_{model_id}.pkl")
with open(_path, "wb") as f:
pickle.dump(self, f)
return self
def __str__(self):
str = f"[Transformer VGF (t)]\n- model_name: {self.model_name}\n- max_length: {self.max_length}\n- batch_size: {self.batch_size}\n- batch_size_eval: {self.batch_size_eval}\n- lr: {self.lr}\n- epochs: {self.epochs}\n- device: {self.device}\n- print_steps: {self.print_steps}\n- evaluate_step: {self.evaluate_step}\n- patience: {self.patience}\n- probabilistic: {self.probabilistic}\n"
return str
class MultilingualDatasetTorch(Dataset):
def __init__(self, lX, lY, split="train"):
self.lX = lX
self.lY = lY
self.split = split
self.langs = []
self.init()
def init(self):
self.X = torch.vstack([data.input_ids for data in self.lX.values()])
if self.split != "whole":
self.Y = torch.vstack([torch.Tensor(data) for data in self.lY.values()])
self.langs = sum(
[
v
for v in {
lang: [lang] * len(data.input_ids) for lang, data in self.lX.items()
}.values()
],
[],
)
return self
def __len__(self):
return len(self.X)
def __getitem__(self, index):
if self.split == "whole":
return self.X[index], self.langs[index]
return self.X[index], self.Y[index], self.langs[index]
class Trainer:
def __init__(
self,
model,
optimizer_name,
device,
loss_fn,
lr,
print_steps,
evaluate_step,
patience,
experiment_name,
):
self.device = device
self.model = model.to(device)
self.optimizer = self.init_optimizer(optimizer_name, lr)
self.evaluate_steps = evaluate_step
self.loss_fn = loss_fn.to(device)
self.print_steps = print_steps
self.earlystopping = EarlyStopping(
patience=patience,
checkpoint_path="models/vgfs/transformers/",
verbose=True,
experiment_name=experiment_name,
)
def init_optimizer(self, optimizer_name, lr):
if optimizer_name.lower() == "adamw":
return AdamW(self.model.parameters(), lr=lr)
else:
raise ValueError(f"Optimizer {optimizer_name} not supported")
def train(self, train_dataloader, eval_dataloader, epochs=10):
print(
f"""- Training params:
- epochs: {epochs}
- learning rate: {self.optimizer.defaults['lr']}
- train batch size: {train_dataloader.batch_size}
- eval batch size: {eval_dataloader.batch_size}
- max len: {train_dataloader.dataset.X.shape[-1]}\n""",
)
for epoch in range(epochs):
self.train_epoch(train_dataloader, epoch)
if (epoch + 1) % self.evaluate_steps == 0:
metric_watcher = self.evaluate(eval_dataloader)
stop = self.earlystopping(metric_watcher, self.model, epoch + 1)
if stop:
break
return self.model
def train_epoch(self, dataloader, epoch):
self.model.train()
for b_idx, (x, y, lang) in enumerate(dataloader):
self.optimizer.zero_grad()
y_hat = self.model(x.to(self.device))
loss = self.loss_fn(y_hat.logits, y.to(self.device))
loss.backward()
self.optimizer.step()
if b_idx % self.print_steps == 0:
print(f"Epoch: {epoch+1} Step: {b_idx+1} Loss: {loss:.4f}")
return self
def evaluate(self, dataloader):
self.model.eval()
lY = defaultdict(list)
lY_hat = defaultdict(list)
for b_idx, (x, y, lang) in enumerate(dataloader):
y_hat = self.model(x.to(self.device))
loss = self.loss_fn(y_hat.logits, y.to(self.device))
predictions = predict(y_hat.logits, classification_type="multilabel")
for l, _true, _pred in zip(lang, y, predictions):
lY[l].append(_true.detach().cpu().numpy())
lY_hat[l].append(_pred)
for lang in lY:
lY[lang] = np.vstack(lY[lang])
lY_hat[lang] = np.vstack(lY_hat[lang])
l_eval = evaluate(lY, lY_hat)
average_metrics = log_eval(l_eval, phase="validation")
return average_metrics[0] # macro-F1
class EarlyStopping:
def __init__(
self,
patience=5,
min_delta=0,
verbose=True,
checkpoint_path="checkpoint.pt",
experiment_name="experiment",
):
self.patience = patience
self.min_delta = min_delta
self.counter = 0
self.best_score = 0
self.best_epoch = None
self.verbose = verbose
self.checkpoint_path = checkpoint_path
self.experiment_name = experiment_name
def __call__(self, validation, model, epoch):
if validation > self.best_score:
print(
f"- earlystopping: Validation score improved from {self.best_score:.3f} to {validation:.3f}"
)
self.best_score = validation
self.counter = 0
# self.save_model(model)
elif validation < (self.best_score + self.min_delta):
self.counter += 1
print(
f"- earlystopping: Validation score decreased from {self.best_score:.3f} to {validation:.3f}, current patience: {self.patience - self.counter}"
)
if self.counter >= self.patience:
if self.verbose:
print(f"- earlystopping: Early stopping at epoch {epoch}")
return True
def save_model(self, model):
_checkpoint_dir = os.path.join(self.checkpoint_path, self.experiment_name)
print(f"- saving model to {_checkpoint_dir}")
os.makedirs(_checkpoint_dir, exist_ok=True)
model.save_pretrained(_checkpoint_dir)
def predict(logits, classification_type="multilabel"):
"""
Converts soft precictions to hard predictions [0,1]
"""
if classification_type == "multilabel":
prediction = torch.sigmoid(logits) > 0.5
elif classification_type == "singlelabel":
prediction = torch.argmax(logits, dim=1).view(-1, 1)
else:
print("unknown classification type")
return prediction.detach().cpu().numpy()