代码实现Vision Transformer图像分类的系统测试
时间: 2023-06-13 15:05:57 浏览: 186
以下是一个简单的代码实现Vision Transformer图像分类的系统测试的示例。这个示例使用PyTorch和Hugging Face Transformers库。
首先,我们需要安装必要的库:
```
pip install torch torchvision transformers
```
然后,我们可以定义模型并训练它:
```python
import torch
import torch.nn as nn
from transformers import ViTModel
class ViTClassifier(nn.Module):
def __init__(self, num_classes):
super().__init__()
self.vit = ViTModel.from_pretrained('google/vit-base-patch16-224')
self.fc = nn.Linear(self.vit.config.hidden_size, num_classes)
def forward(self, x):
x = self.vit(x)['last_hidden_state'][:, 0, :]
x = self.fc(x)
return x
model = ViTClassifier(num_classes=10)
optimizer = torch.optim.Adam(model.parameters(), lr=1e-4)
criterion = nn.CrossEntropyLoss()
# Train the model
for epoch in range(num_epochs):
for i, (inputs, labels) in enumerate(train_loader):
optimizer.zero_grad()
outputs = model(inputs)
loss = criterion(outputs, labels)
loss.backward()
optimizer.step()
```
接下来,我们可以对模型进行测试:
```python
# Test the model
model.eval()
correct = 0
total = 0
with torch.no_grad():
for inputs, labels in test_loader:
outputs = model(inputs)
_, predicted = torch.max(outputs.data, 1)
total += labels.size(0)
correct += (predicted == labels).sum().item()
accuracy = 100 * correct / total
print('Accuracy: {}%'.format(accuracy))
```
这个示例使用了预训练的ViT模型来进行图像分类。我们首先定义一个ViTClassifier类来包装ViT模型,并添加一个全连接层来进行分类。然后,我们使用交叉熵损失和Adam优化器来训练模型。最后,我们使用测试集来计算模型的准确率。
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