PyTorch回归问题的简易思路模板

数据集来自:ML2023Spring-hw1

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import math, csv, os
import numpy as np
import pandas as pd
from tqdm import tqdm
import torch
import torch.nn as nn
from torch.utils.data import Dataset, DataLoader, random_split
from torch.utils.tensorboard import SummaryWriter

device = 'cuda' if torch.cuda.is_available() else 'cpu'
config = {
'seed': 114514, # 随机数种子,用于复现
'select_all': True, # Whether to use all features.
'valid_ratio': 0.2, # validation_size = train_size * valid_ratio
'n_epochs': 50000,
'batch_size': 512,
'learning_rate': 1e-5,
'early_stop': 400, # If model has not improved for this many consecutive epochs, stop training.
'save_path': './models/model.ckpt'
}


def same_seed(seed):
torch.backends.cudnn.deterministic = True
torch.backends.cudnn.benchmark = False
np.random.seed(seed)
torch.manual_seed(seed)
if torch.cuda.is_available():
torch.cuda.manual_seed_all(seed)


def train_valid_split(data_set, valid_ratio, seed):
valid_set_size = int(valid_ratio * len(data_set))
train_set_size = len(data_set) - valid_set_size
train_set, valid_set = random_split(data_set, [train_set_size, valid_set_size],
generator=torch.Generator().manual_seed(seed))
return np.array(train_set), np.array(valid_set)


def select_feat(train_data, valid_data, test_data, select_all=True):
y_train, y_valid = train_data[:, -1], valid_data[:, -1]
raw_x_train, raw_x_valid, raw_x_test = train_data[:, :-1], valid_data[:, :-1], test_data

if select_all:
feat_idx = list(range(raw_x_train.shape[1]))
else:
feat_idx = [0, 1, 2, 3, 4]

return raw_x_train[:, feat_idx], raw_x_valid[:, feat_idx], raw_x_test[:, feat_idx], y_train, y_valid


def predict(test_loader, model, device):
model.eval()
preds = []
for x in tqdm(test_loader):
x = x.to(device)
with torch.no_grad():
pred = model(x)
preds.append(pred.detach().cpu())
preds = torch.cat(preds, dim=0).numpy()
return preds

def trainer(train_loader, valid_loader, model, config, device):
criterion = nn.MSELoss(reduction='mean')
optimizer = torch.optim.Adam(model.parameters(), lr=config['learning_rate'])

writer = SummaryWriter()

if not os.path.isdir('./models'):
os.mkdir('./models')

n_epochs, best_loss, step, early_stop_count = config['n_epochs'], math.inf, 0, 0

for epoch in range(n_epochs):
model.train()
loss_record = []

train_pbar = tqdm(train_loader, position=0, leave=True)
# train_pbar = tqdm(train_loader)

for x, y in train_pbar:
optimizer.zero_grad()
x, y = x.to(device), y.to(device)
pred = model(x)
loss = criterion(pred, y)
loss.backward()
optimizer.step()
step += 1
loss_record.append(loss.detach().item())

train_pbar.set_description(f'Epoch [{epoch + 1}/{n_epochs}]')
train_pbar.set_postfix({'loss': loss.detach().item()})

mean_train_loss = sum(loss_record) / len(loss_record)
writer.add_scalar('Loss/train', mean_train_loss, step)

model.eval()
loss_record =[]
for x, y in valid_loader:
x, y = x.to(device), y.to(device)
with torch.no_grad():
pred = model(x)
loss = criterion(pred, y)

loss_record.append(loss.item())

mean_valid_loss = sum(loss_record) / len(loss_record)
print(f'Epoch [{epoch + 1}/{n_epochs}]: Train loss: {mean_train_loss:.4f}, Valid loss: {mean_valid_loss:.4f}')
writer.add_scalar('Loss/valid', mean_valid_loss, step)

if mean_valid_loss < best_loss:
best_loss = mean_valid_loss
torch.save(model.state_dict(), config['save_path'])
print('Saving model with loss {:.3f}...'.format(best_loss))
early_stop_count = 0
else:
early_stop_count += 1

if early_stop_count >= config['early_stop']:
print('\nModel is not improving, so we halt the training session.')
return


def save_pred(preds, file):
with open(file, 'w') as fp:
writer = csv.writer(fp)
writer.writerow(['id', 'tested_positive'])
for i, p in enumerate(preds):
writer.writerow([i, p])

class COVID19Dataset(Dataset):
def __init__(self, x, y=None):
if y is None:
self.y = y
else:
self.y = torch.FloatTensor(y)
self.x = torch.FloatTensor(x)

def __getitem__(self, item):
if self.y is None:
return self.x[item]
else:
return self.x[item], self.y[item]

def __len__(self):
return len(self.x)


class My_Model(nn.Module):
def __init__(self, input_dim):
super(My_Model, self).__init__()
self.layers = nn.Sequential(
nn.Linear(input_dim, 16),
nn.LeakyReLU(),
nn.Linear(16, 8),
nn.LeakyReLU(),
nn.Linear(8, 1)
)

def forward(self, x):
x = self.layers(x)
print(type(x))
print(x.shape)
x = x.squeeze(1) # (B, 1) -> (B)
return x




# --------------------------------


train_data, test_data = pd.read_csv('./covid_train.csv').values, pd.read_csv('./covid_test.csv').values
train_data, valid_data = train_valid_split(train_data, config['valid_ratio'], config['seed'])

x_train, x_valid, x_test, y_train, y_valid = select_feat(train_data, valid_data, test_data, config['select_all'])

train_dataset, valid_dataset, test_dataset = COVID19Dataset(x_train, y_train), COVID19Dataset(x_valid, y_valid), COVID19Dataset(x_test)

train_loader = DataLoader(train_dataset, batch_size=config['batch_size'], shuffle=True, pin_memory=True)
valid_loader = DataLoader(valid_dataset, batch_size=config['batch_size'], shuffle=True, pin_memory=True)
test_loader = DataLoader(test_dataset, batch_size=config['batch_size'], shuffle=False, pin_memory=True)


model = My_Model(input_dim=x_train.shape[1]).to(device)
trainer(train_loader, valid_loader, model, config, device)


model.load_state_dict(torch.load(config['save_path']))
preds = predict(test_loader, model, device)
save_pred(preds, 'pred.csv')


作者

Jhuoer Yen

发布于

2024-01-16

更新于

2024-01-16

许可协议

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