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下面是一个使用PyTorch实现GRU分类模型的示例代码:
import torch
import torch.nn as nn
import torch.optim as optim
from torch.utils.data import Dataset, DataLoader
from sklearn.model_selection import train_test_split
# 自定义数据集类
class MyDataset(Dataset):
def __init__(self, data):
self.data = data
def __len__(self):
return len(self.data)
def __getitem__(self, idx):
sample = self.data[idx]
x = torch.FloatTensor(sample[:-1])
y = torch.LongTensor([sample[-1]])
return x, y
# 定义GRU分类模型
class GRUClassifier(nn.Module):
def __init__(self, input_size, hidden_size, num_classes):
super(GRUClassifier, self).__init__()
self.hidden_size = hidden_size
self.gru = nn.GRU(input_size, hidden_size, batch_first=True)
self.fc = nn.Linear(hidden_size, num_classes)
def forward(self, x):
output, _ = self.gru(x)
output = output[:, -1, :]
output = self.fc(output)
return output
# 准备数据
data = []
with open('data.txt', 'r') as f:
for line in f:
sample = list(map(float, line.strip().split(',')))
data.append(sample)
train_data, test_data = train_test_split(data, test_size=0.2, random_state=42)
train_data, val_data = train_test_split(train_data, test_size=0.2, random_state=42)
train_dataset = MyDataset(train_data)
val_dataset = MyDataset(val_data)
test_dataset = MyDataset(test_data)
train_loader = DataLoader(train_dataset, batch_size=32, shuffle=True)
val_loader = DataLoader(val_dataset, batch_size=32, shuffle=False)
test_loader = DataLoader(test_dataset, batch_size=32, shuffle=False)
# 定义模型参数和优化器
input_size = len(data[0]) - 1
hidden_size = 128
num_classes = 8
model = GRUClassifier(input_size, hidden_size, num_classes)
criterion = nn.CrossEntropyLoss()
optimizer = optim.Adam(model.parameters(), lr=0.001)
# 训练模型
device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
model.to(device)
best_val_acc = 0.0
for epoch in range(10):
model.train()
train_correct = 0
train_total = 0
for inputs, labels in train_loader:
inputs = inputs.to(device)
labels = labels.squeeze().to(device)
optimizer.zero_grad()
outputs = model(inputs)
_, predicted = torch.max(outputs.data, 1)
loss = criterion(outputs, labels)
loss.backward()
optimizer.step()
train_total += labels.size(0)
train_correct += (predicted == labels).sum().item()
train_acc = train_correct / train_total
model.eval()
val_correct = 0
val_total = 0
with torch.no_grad():
for inputs, labels in val_loader:
inputs = inputs.to(device)
labels = labels.squeeze().to(device)
outputs = model(inputs)
_, predicted = torch.max(outputs.data, 1)
val_total += labels.size(0)
val_correct += (predicted == labels).sum().item()
val_acc = val_correct / val_total
if val_acc > best_val_acc:
best_val_acc = val_acc
torch.save(model.state_dict(), 'best_model.pt')
print('Epoch [{}/{}], Train Acc: {:.2f}, Val Acc: {:.2f}'.format(epoch+1, 10, train_acc, val_acc))
# 在测试集上评估模型
model.load_state_dict(torch.load('best_model.pt'))
model.eval()
test_correct = 0
test_total = 0
with torch.no_grad():
for inputs, labels in test_loader:
inputs = inputs.to(device)
labels = labels.squeeze().to(device)
outputs = model(inputs)
_, predicted = torch.max(outputs.data, 1)
test_total += labels.size(0)
test_correct += (predicted == labels).sum().item()
test_acc = test_correct / test_total
print('Test Acc: {:.2f}'.format(test_acc))
上述代码中,首先定义了一个自定义的数据集类MyDataset,用于加载和处理数据。然后定义了一个GRU分类模型GRUClassifier,包含一个GRU层和一个全连接层。接下来,使用train_test_split函数将原始数据划分为训练集、验证集和测试集,并创建相应的数据加载器。然后定义模型参数和优化器。接着进入训练循环,每个epoch中,先将模型设为训练模式,然后遍历训练集进行训练,并计算训练准确率。然后将模型设为评估模式,遍历验证集计算验证准确率,并保存在验证集上表现最好的模型。最后,在测试集上评估模型的准确率
原文地址: https://www.cveoy.top/t/topic/id49 著作权归作者所有。请勿转载和采集!