x_0 = x[0].contiguous().view(x[0].size(0),-1)
时间: 2024-05-25 14:12:54 浏览: 18
这行代码的作用是将输入x的第一个元素x[0]按行展开成一个二维矩阵,并将其变形为一个形状为(x[0].size(0), -1)的二维矩阵。具体来说,x[0].contiguous()是为了保证数据在内存中是连续存储的,这样才能进行view操作;view操作则是将张量的形状变为指定的形状,这里将第一维保持不变,第二维变为-1,表示让PyTorch自动计算第二维的大小,以保证张量的元素总数不变。这样操作之后,x_0就是一个二维的张量,可以被输入到全连接层等需要二维张量输入的模块中。
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这段代码中加一个test loss功能 class LSTM(nn.Module): def __init__(self, input_size, hidden_size, num_layers, output_size, batch_size, device): super().__init__() self.device = device self.input_size = input_size self.hidden_size = hidden_size self.num_layers = num_layers self.output_size = output_size self.num_directions = 1 # 单向LSTM self.batch_size = batch_size self.lstm = nn.LSTM(self.input_size, self.hidden_size, self.num_layers, batch_first=True) self.linear = nn.Linear(65536, self.output_size) def forward(self, input_seq): h_0 = torch.randn(self.num_directions * self.num_layers, self.batch_size, self.hidden_size).to(self.device) c_0 = torch.randn(self.num_directions * self.num_layers, self.batch_size, self.hidden_size).to(self.device) output, _ = self.lstm(input_seq, (h_0, c_0)) pred = self.linear(output.contiguous().view(self.batch_size, -1)) return pred if __name__ == '__main__': # 加载已保存的模型参数 saved_model_path = '/content/drive/MyDrive/危急值/model/dangerous.pth' device = 'cuda:0' lstm_model = LSTM(input_size=1, hidden_size=64, num_layers=1, output_size=3, batch_size=256, device='cuda:0').to(device) state_dict = torch.load(saved_model_path) lstm_model.load_state_dict(state_dict) dataset = ECGDataset(X_train_df.to_numpy()) dataloader = DataLoader(dataset, batch_size=256, shuffle=True, num_workers=0, drop_last=True) loss_fn = nn.CrossEntropyLoss() optimizer = optim.SGD(lstm_model.parameters(), lr=1e-4) for epoch in range(200000): print(f'epoch:{epoch}') lstm_model.train() epoch_bar = tqdm(dataloader) for x, y in epoch_bar: optimizer.zero_grad() x_out = lstm_model(x.to(device).type(torch.cuda.FloatTensor)) loss = loss_fn(x_out, y.long().to(device)) loss.backward() epoch_bar.set_description(f'loss:{loss.item():.4f}') optimizer.step() if epoch % 100 == 0 or epoch == epoch - 1: torch.save(lstm_model.state_dict(), "/content/drive/MyDrive/危急值/model/dangerous.pth") print("权重成功保存一次")
以下是加入 Test Loss 功能后的代码:
```python
import torch
import torch.nn as nn
import torch.optim as optim
from torch.utils.data import DataLoader
class LSTM(nn.Module):
def __init__(self, input_size, hidden_size, num_layers, output_size, batch_size, device):
super().__init__()
self.device = device
self.input_size = input_size
self.hidden_size = hidden_size
self.num_layers = num_layers
self.output_size = output_size
self.num_directions = 1 # 单向LSTM
self.batch_size = batch_size
self.lstm = nn.LSTM(self.input_size, self.hidden_size, self.num_layers, batch_first=True)
self.linear = nn.Linear(65536, self.output_size)
def forward(self, input_seq):
h_0 = torch.randn(self.num_directions * self.num_layers, self.batch_size, self.hidden_size).to(self.device)
c_0 = torch.randn(self.num_directions * self.num_layers, self.batch_size, self.hidden_size).to(self.device)
output, _ = self.lstm(input_seq, (h_0, c_0))
pred = self.linear(output.contiguous().view(self.batch_size, -1))
return pred
if __name__ == '__main__':
# 加载已保存的模型参数
saved_model_path = '/content/drive/MyDrive/危急值/model/dangerous.pth'
device = 'cuda:0'
lstm_model = LSTM(input_size=1, hidden_size=64, num_layers=1, output_size=3, batch_size=256, device=device).to(device)
state_dict = torch.load(saved_model_path)
lstm_model.load_state_dict(state_dict)
# 加载测试数据集
test_dataset = ECGDataset(X_test_df.to_numpy())
test_loader = DataLoader(test_dataset, batch_size=256, shuffle=False, num_workers=0, drop_last=False)
# 定义损失函数和优化器
loss_fn = nn.CrossEntropyLoss()
optimizer = optim.SGD(lstm_model.parameters(), lr=1e-4)
# 开始训练
for epoch in range(200000):
print(f'epoch:{epoch}')
lstm_model.train()
epoch_bar = tqdm(dataloader)
for x, y in epoch_bar:
optimizer.zero_grad()
x_out = lstm_model(x.to(device).type(torch.cuda.FloatTensor))
loss = loss_fn(x_out, y.long().to(device))
loss.backward()
epoch_bar.set_description(f'loss:{loss.item():.4f}')
optimizer.step()
# 计算测试集上的平均损失
test_loss = 0.0
lstm_model.eval()
with torch.no_grad():
for x, y in test_loader:
x_out = lstm_model(x.to(device).type(torch.cuda.FloatTensor))
loss = loss_fn(x_out, y.long().to(device))
test_loss += loss.item() * x.size(0)
test_loss /= len(test_dataset)
print(f'Test Loss: {test_loss:.4f}')
if epoch % 100 == 0 or epoch == epoch - 1:
torch.save(lstm_model.state_dict(), "/content/drive/MyDrive/危急值/model/dangerous.pth")
print("权重成功保存一次")
```
在这个代码中,我们首先加载了测试数据集 `test_dataset` 和测试数据加载器 `test_loader`。在每个 epoch 完成后,我们计算测试集上的平均损失值。我们使用 `lstm_model.eval()` 将模型设为评估模式,并利用 `torch.no_grad()` 避免计算梯度,以加速计算。最后,我们输出测试集上的平均损失值。
import torch import torch.nn as nn import torch.nn.functional as F import torchvision.models as models import os class FCNTransformerNet(nn.Module): def __init__(self, num_classes): super(FCNTransformerNet, self).__init__() self.fcn_backbone = models.segmentation.fcn_resnet50(pretrained=True).backbone self.fcn_backbone.conv1 = nn.Conv2d(3, 64, kernel_size=7, stride=2, padding=3, bias=False) self.transformer_layers = nn.TransformerEncoderLayer(d_model=2048, nhead=8) self.transformer_encoder = nn.TransformerEncoder(self.transformer_layers, num_layers=6) self.classification_head = nn.Sequential( nn.Linear(2048, 512), nn.ReLU(), nn.Linear(512, num_classes) ) def forward(self, x): fcn_output = self.fcn_backbone(x)['out'] fcn_output = fcn_output.view(fcn_output.size(0), fcn_output.size(1), -1) fcn_output = fcn_output.permute(2, 0, 1) transformer_output = self.transformer_encoder(fcn_output) transformer_output = transformer_output.permute(1, 2, 0) transformer_output = transformer_output.contiguous().view(transformer_output.size(0), -1, 1, 1) output = self.classification_head(transformer_output) return output FCNTransformerNet net = FCNTransformerNet(num_classes=2) input_batch = torch.randn(4, 3, 512, 512) output_batch = net(input_batch) print(output_batch.size()) # Should print: torch.Size([4, 2, 512, 512]) 运行这段代码,并改错
在这段代码中,有几个问题需要进行修正。
首先,你定义了一个名为 `FCNTransformerNet` 的类,但是没有在代码末尾实例化这个类。你需要添加 `()` 来实例化该类,将其赋值给变量 `net`。
其次,你需要将 `FCNTransformerNet` 类的定义放在 `if __name__ == "__main__":` 条件语句内部,以确保它只在主程序中运行,而不是在模块导入时运行。
最后,你的代码中缺少了一些必要的导入语句。你需要导入 `torch`, `torch.nn` 和 `torchvision.models`。
下面是修改后的代码:
```python
import torch
import torch.nn as nn
import torchvision.models as models
class FCNTransformerNet(nn.Module):
def __init__(self, num_classes):
super(FCNTransformerNet, self).__init__()
self.fcn_backbone = models.segmentation.fcn_resnet50(pretrained=True).backbone
self.fcn_backbone.conv1 = nn.Conv2d(3, 64, kernel_size=7, stride=2, padding=3, bias=False)
self.transformer_layers = nn.TransformerEncoderLayer(d_model=2048, nhead=8)
self.transformer_encoder = nn.TransformerEncoder(self.transformer_layers, num_layers=6)
self.classification_head = nn.Sequential(
nn.Linear(2048, 512),
nn.ReLU(),
nn.Linear(512, num_classes)
)
def forward(self, x):
fcn_output = self.fcn_backbone(x)['out']
fcn_output = fcn_output.view(fcn_output.size(0), fcn_output.size(1), -1)
fcn_output = fcn_output.permute(2, 0, 1)
transformer_output = self.transformer_encoder(fcn_output)
transformer_output = transformer_output.permute(1, 2, 0)
transformer_output = transformer_output.contiguous().view(transformer_output.size(0), -1, 1, 1)
output = self.classification_head(transformer_output)
return output
if __name__ == "__main__":
net = FCNTransformerNet(num_classes=2)
input_batch = torch.randn(4, 3, 512, 512)
output_batch = net(input_batch)
print(output_batch.size()) # Should print: torch.Size([4, 2, 512, 512])
```
请注意,这段代码假设你已经正确安装了 `torch` 和 `torchvision` 库。如果出现任何错误,你可能需要检查这些库的安装情况。