This commit is contained in:
wangobango 2021-06-22 14:03:36 +02:00
parent 023a4e4361
commit 43dbf81d83
3 changed files with 111 additions and 278 deletions

View File

@ -9,48 +9,50 @@ import numpy as np
from model import BERT_Arch
from sklearn.metrics import classification_report
from sklearn.metrics import accuracy_score
from transformers import BertTokenizerFast, BertForSequenceClassification
from transformers import Trainer, TrainingArguments
path = 'saved_weights.pt'
tokenizer = BertTokenizer.from_pretrained('bert-base-uncased')
device = torch.device("cuda")
class Dataset(torch.utils.data.Dataset):
def __init__(self, encodings, labels):
self.encodings = encodings
self.labels = labels
bert = AutoModelForSequenceClassification.from_pretrained('bert-base-uncased')
def __getitem__(self, idx):
item = {k: torch.tensor(v[idx]) for k, v in self.encodings.items()}
item["labels"] = torch.tensor([self.labels[idx]])
return item
model = BERT_Arch(bert)
model.load_state_dict(torch.load(path))
model.to(device)
def __len__(self):
return len(self.labels)
test_data = pd.read_csv("dev-0/in.tsv", sep="\t")
test_data.columns = ["text", "d"]
device = torch.device('cuda')
test_target = pd.read_csv("dev-0/expected.tsv", sep="\t")
train_texts = \
pd.read_csv('train/in.tsv.xz', compression='xz', sep='\t', header=None, error_bad_lines=False, quoting=3)[0].tolist()[:1000]
train_labels = pd.read_csv('train/expected.tsv', sep='\t', header=None, quoting=3)[0].tolist()[:1000]
dev_texts = pd.read_csv('dev-0/in.tsv.xz', compression='xz', sep='\t', header=None, quoting=3)[0].tolist()[:1000]
dev_labels = pd.read_csv('dev-0/expected.tsv', sep='\t', header=None, quoting=3)[0].tolist()[:1000]
model_name = "bert-base-uncased"
tokens_train = tokenizer.batch_encode_plus(
test_data["text"],
max_length = 25,
padding='max_length',
truncation=True
)
model = BertForSequenceClassification.from_pretrained(
model_name, num_labels=len(pd.unique(train_labels))).to(device)
max_length = 512
tokenizer = BertTokenizerFast.from_pretrained(model_name, do_lower_case=True)
test_seq = torch.tensor(tokens_train['input_ids'])
test_mask = torch.tensor(tokens_train['attention_mask'])
# model.load_pretrained(model_path)
# tokenizer.load_pretrainded(model_path)
#define a batch size
batch_size = 32
train_encodings = tokenizer(train_texts, truncation=True, padding=True, max_length=max_length)
valid_encodings = tokenizer(dev_texts, truncation=True, padding=True, max_length=max_length)
# wrap tensors
test_data = TensorDataset(test_seq, test_mask)
# sampler for sampling the data during training
test_sampler = RandomSampler(test_data)
# dataLoader for train set
test_dataloader = DataLoader(test_data, sampler=test_sampler, batch_size=batch_size)
input_ids = torch.tensor(valid_encodings.data['input_ids'])[:100]
attention_mask = torch.tensor(valid_encodings.data['attention_mask'])[:100]
with torch.no_grad():
preds = model(test_seq.to(device), test_mask.to(device))
preds = preds.detach().cpu().numpy()
preds = model(input_ids.to(device), attention_mask.to(device))
preds = preds.logits.detach().cpu().numpy()
preds = np.argmax(preds, axis = 1)
print(classification_report(test_target['0'], preds))
print(accuracy_score(test_target['0'], preds))
print(preds)
print(classification_report(dev_labels, preds))
print(accuracy_score(dev_labels, preds))

279
main.py
View File

@ -1,215 +1,90 @@
import pandas as pd
from transformers import BertTokenizer, AdamW, AutoModelForSequenceClassification
import torch
import matplotlib.pyplot as plt
from torch.utils.data import TensorDataset, DataLoader, RandomSampler
import torch.nn as nn
from sklearn.utils.class_weight import compute_class_weight
from transformers.file_utils import is_torch_available
from transformers import BertTokenizerFast, BertForSequenceClassification
from transformers import Trainer, TrainingArguments
import numpy as np
from model import BERT_Arch
train_input_path = "train/in.tsv"
train_target_path = "train/expected.tsv"
train_input = pd.read_csv(train_input_path, sep="\t")
train_input.columns=["text", "d"]
train_target = pd.read_csv(train_target_path, sep="\t")
tokenizer = BertTokenizer.from_pretrained('bert-base-uncased')
device = torch.device("cuda")
import random
from sklearn.metrics import accuracy_score
import pandas as pd
# seq_len = [len(i.split()) for i in train_input["text"]]
class Dataset(torch.utils.data.Dataset):
def __init__(self, encodings, labels):
self.encodings = encodings
self.labels = labels
# pd.Series(seq_len).hist(bins = 30)
# plt.show()
def __getitem__(self, idx):
item = {k: torch.tensor(v[idx]) for k, v in self.encodings.items()}
item["labels"] = torch.tensor([self.labels[idx]])
return item
bert = AutoModelForSequenceClassification.from_pretrained('bert-base-uncased')
def __len__(self):
return len(self.labels)
tokens_train = tokenizer.batch_encode_plus(
train_input["text"],
max_length = 25,
padding='max_length',
truncation=True
def set_seed(seed: int):
random.seed(seed)
np.random.seed(seed)
if is_torch_available():
torch.manual_seed(seed)
torch.cuda.manual_seed_all(seed)
def compute_metrics(pred):
labels = pred.label_ids
preds = pred.predictions.argmax(-1)
acc = accuracy_score(labels, preds)
return {
'accuracy': acc,
}
set_seed(1)
train_texts = \
pd.read_csv('train/in.tsv.xz', compression='xz', sep='\t', header=None, error_bad_lines=False, quoting=3)[0].tolist()
train_labels = pd.read_csv('train/expected.tsv', sep='\t', header=None, quoting=3)[0].tolist()
dev_texts = pd.read_csv('dev-0/in.tsv.xz', compression='xz', sep='\t', header=None, quoting=3)[0].tolist()
dev_labels = pd.read_csv('dev-0/expected.tsv', sep='\t', header=None, quoting=3)[0].tolist()
# test_texts = pd.read_table('test-A/in.tsv.xz', compression='xz', sep='\t', header=None, quoting=3)
model_name = "bert-base-uncased"
max_length = 25
tokenizer = BertTokenizerFast.from_pretrained(model_name, do_lower_case=True)
train_encodings = tokenizer(train_texts, truncation=True, padding=True, max_length=max_length)
valid_encodings = tokenizer(dev_texts, truncation=True, padding=True, max_length=max_length)
train_dataset = Dataset(train_encodings, train_labels)
valid_dataset = Dataset(valid_encodings, dev_labels)
model = BertForSequenceClassification.from_pretrained(
model_name, num_labels=len(pd.unique(train_labels))).to("cuda")
training_args = TrainingArguments(
output_dir='./results', # output directory
num_train_epochs=3, # total number of training epochs
per_device_train_batch_size=1, # batch size per device during training
per_device_eval_batch_size=1, # batch size for evaluation
warmup_steps=500, # number of warmup steps for learning rate scheduler
weight_decay=0.01, # strength of weight decay
logging_dir='./logs', # directory for storing logs
load_best_model_at_end=True, # load the best model when finished training (default metric is loss)
# but you can specify `metric_for_best_model` argument to change to accuracy or other metric
logging_steps=200, # log & save weights each logging_steps
evaluation_strategy="steps", # evaluate each `logging_steps`
)
train_seq = torch.tensor(tokens_train['input_ids'])
train_mask = torch.tensor(tokens_train['attention_mask'])
train_y = torch.tensor(train_target.to_numpy())
trainer = Trainer(
model=model, # the instantiated Transformers model to be trained
args=training_args, # training arguments, defined above
train_dataset=train_dataset, # training dataset
eval_dataset=valid_dataset, # evaluation dataset
compute_metrics=compute_metrics, # the callback that computes metrics of interest
)
#define a batch size
batch_size = 32
trainer.train()
# wrap tensors
train_data = TensorDataset(train_seq, train_mask, train_y)
trainer.evaluate()
# sampler for sampling the data during training
train_sampler = RandomSampler(train_data)
# dataLoader for train set
train_dataloader = DataLoader(train_data, sampler=train_sampler, batch_size=batch_size)
for param in bert.parameters():
param.requires_grad = False
model = BERT_Arch(bert)
model = model.to(device)
# model.cuda(0)
optimizer = AdamW(model.parameters(), lr = 1e-5)
class_weights = compute_class_weight('balanced', np.unique(train_target.to_numpy()), train_target['1'])
weights= torch.tensor(class_weights,dtype=torch.float)
weights = weights.to(device)
# define the loss function
cross_entropy = nn.NLLLoss(weight=weights)
# number of training epochs
epochs = 10
def train():
model.train()
total_loss, total_accuracy = 0, 0
# empty list to save model predictions
total_preds=[]
# iterate over batches
for step,batch in enumerate(train_dataloader):
# progress update after every 50 batches.
if step % 50 == 0 and not step == 0:
print(' Batch {:>5,} of {:>5,}.'.format(step, len(train_dataloader)))
# push the batch to gpu
batch = [r.to(device) for r in batch]
sent_id, mask, labels = batch
# clear previously calculated gradients
model.zero_grad()
# get model predictions for the current batch
preds = model(sent_id, mask)
# compute the loss between actual and predicted values
labels = torch.tensor([x[0] for x in labels]).to(device)
loss = cross_entropy(preds, labels)
# add on to the total loss
total_loss = total_loss + loss.item()
# backward pass to calculate the gradients
loss.backward()
# clip the the gradients to 1.0. It helps in preventing the exploding gradient problem
torch.nn.utils.clip_grad_norm_(model.parameters(), 1.0)
# update parameters
optimizer.step()
# model predictions are stored on GPU. So, push it to CPU
preds=preds.detach().cpu().numpy()
# append the model predictions
total_preds.append(preds)
# compute the training loss of the epoch
avg_loss = total_loss / len(train_dataloader)
# predictions are in the form of (no. of batches, size of batch, no. of classes).
# reshape the predictions in form of (number of samples, no. of classes)
total_preds = np.concatenate(total_preds, axis=0)
#returns the loss and predictions
return avg_loss, total_preds
def evaluate():
print("\nEvaluating...")
# deactivate dropout layers
model.eval()
total_loss, total_accuracy = 0, 0
# empty list to save the model predictions
total_preds = []
# iterate over batches
for step,batch in enumerate(train_dataloader):
# Progress update every 50 batches.
if step % 50 == 0 and not step == 0:
# Calculate elapsed time in minutes.
# Report progress.
print(' Batch {:>5,} of {:>5,}.'.format(step, len(train_dataloader)))
# push the batch to gpu
batch = [t.to(device) for t in batch]
sent_id, mask, labels = batch
# deactivate autograd
with torch.no_grad():
# model predictions
preds = model(sent_id, mask)
# compute the validation loss between actual and predicted values
labels = torch.tensor([x[0] for x in labels]).to(device)
loss = cross_entropy(preds,labels)
total_loss = total_loss + loss.item()
preds = preds.detach().cpu().numpy()
total_preds.append(preds)
# compute the validation loss of the epoch
avg_loss = total_loss / len(train_dataloader)
# reshape the predictions in form of (number of samples, no. of classes)
total_preds = np.concatenate(total_preds, axis=0)
return avg_loss, total_preds
# avg_loss, total_preds = train()
# set initial loss to infinite
best_valid_loss = float('inf')
# empty lists to store training and validation loss of each epoch
train_losses=[]
valid_losses=[]
print("Started training!")
#for each epoch
for epoch in range(epochs):
print('\n Epoch {:} / {:}'.format(epoch + 1, epochs))
#train model
train_loss, _ = train()
#evaluate model
valid_loss, _ = evaluate()
#save the best model
if valid_loss < best_valid_loss:
best_valid_loss = valid_loss
torch.save(model.state_dict(), 'saved_weights.pt')
# append training and validation loss
train_losses.append(train_loss)
valid_losses.append(valid_loss)
print(f'\nTraining Loss: {train_loss:.3f}')
print(f'Validation Loss: {valid_loss:.3f}')
print("Finished !!!")
model_path = "bert-base-uncased-pretrained"
model.save_pretrained(model_path)
tokenizer.save_pretrained(model_path)

View File

@ -1,44 +0,0 @@
import torch.nn as nn
class BERT_Arch(nn.Module):
def __init__(self, bert):
super(BERT_Arch, self).__init__()
self.bert = bert
# dropout layer
self.dropout = nn.Dropout(0.1)
# relu activation function
self.relu = nn.ReLU()
# dense layer 1
self.fc1 = nn.Linear(2,512)
# dense layer 2 (Output layer)
self.fc2 = nn.Linear(512,2)
#softmax activation function
self.softmax = nn.LogSoftmax(dim=1)
#define the forward pass
def forward(self, sent_id, mask):
#pass the inputs to the model
senence_classifier_output = self.bert(sent_id, attention_mask=mask)
x = senence_classifier_output.logits.float()
x = self.fc1(x)
x = self.relu(x)
x = self.dropout(x)
# output layer
x = self.fc2(x)
# apply softmax activation
x = self.softmax(x)
return x