为什么我的pytorch模型摘要没有参数？

Question

我是pytorch的初学者。
我想自动编码器模型类似于U-NET。
因此，我在下面进行了代码，并使用pytorch_model_summary参见摘要，但是结果告诉我模型有任何参数...

为什么我的模型有任何参数？

class unet_like(nn.Module):
    def __init__(self):
      super(unet_like, self).__init__()
      
    def conv2d_block(self, in_channels, out_channels, x): 
      x = nn.Conv2d(in_channels=in_channels, out_channels = out_channels, kernel_size = 3, padding = "same")(x)
      x = nn.BatchNorm2d(out_channels)(x)
      x = nn.ReLU()(x)
      x = nn.Conv2d(in_channels = out_channels, out_channels = out_channels, kernel_size = 3, padding = "same")(x)
      x = nn.BatchNorm2d(out_channels)(x)
      x = nn.ReLU()(x)
      return x
    def forward(self, x):
      
      c1 = self.conv2d_block(3, 16, x)
      p1 = nn.MaxPool2d(kernel_size = 2)(c1)
      p1 = nn.Dropout2d(0.1)(p1)

      c2 = self.conv2d_block(16, 32, p1)
      p2 = nn.MaxPool2d(kernel_size = 2)(c2)
      p2 = nn.Dropout(0.1)(p2)

      c3 = self.conv2d_block(32, 64, p2)
      p3 = nn.MaxPool2d(kernel_size = 2)(c3)
      p3 = nn.Dropout(0.1)(p3)

      c4 = self.conv2d_block(64, 128, p3)
      p4 = nn.MaxPool2d(kernel_size = 2)(c4)
      p4 = nn.Dropout(0.1)(p4)

      c5 = self.conv2d_block(128, 256, p4)
      # nn.ConvTranspose2d(in_channels = 16, out_channels = 64, kernel_size = 3, stride = 1, padding = (1, 1)),
      # nn.ReLU(),
      
      u6 = nn.ConvTranspose2d(in_channels=256, out_channels=128, kernel_size = 2, stride = 2, output_padding = (0,1))(c5)
      print(u6.shape)
      print(c4.shape)
      u6 = torch.cat([u6, c4], 1) # u6: 128, c4: 128
      print(u6.shape)
      u6 = nn.Dropout(0.1)(u6)
      c6 = self.conv2d_block(256, 128, u6)

      u7 = nn.ConvTranspose2d(in_channels = 128, out_channels = 64, kernel_size = 2, stride = 2, output_padding = (1,0))(c6)
      u7 = torch.cat([u7, c3], 1)
      u7 = nn.Dropout(0.1)(u7)
      c7 = self.conv2d_block(128, 64, u7)


      u8 = nn.ConvTranspose2d(in_channels = 64, out_channels = 32, kernel_size = 2, stride = 2, output_padding = (0,1))(c7)
      u8 = torch.cat([u8, c2], 1)
      u8 = nn.Dropout(0.1)(u8)
      c8 = self.conv2d_block(64, 32, u8)

      u9 = nn.ConvTranspose2d(in_channels = 32, out_channels = 16, kernel_size = 2, stride = 2, output_padding = (0,1))(c8)
      u9 = torch.cat([u9, c1], 1)
      u9 = nn.Dropout(0.1)(u9)
      c9 = self.conv2d_block(32, 16, u9)
  #           in_channels, kernel_size,  
  # outputs = Conv2D(1, (1, 1), activation = "sigmoid")(c9)

      c9 = nn.Conv2d(in_channels=16, out_channels = 1, kernel_size = 3, padding = (1,1))(c9)
      outputs = nn.Sigmoid()(c9)
      return outputs

model = unet_like().to("cpu")
print(pytorch_model_summary.summary(model, torch.tensor(train_images[:1], dtype = torch.float32).to("cpu"), show_input=True))

torch.Size([1, 128, 12, 9])
torch.Size([1, 128, 12, 9])
torch.Size([1, 256, 12, 9])
-----------------------------------------------------------------------
      Layer (type)         Input Shape         Param #     Tr. Param #
=======================================================================
       unet_like-1     [1, 3, 100, 75]               0               0
=======================================================================
Total params: 0
Trainable params: 0
Non-trainable params: 0
-----------------------------------------------------------------------

Answer 1

您的模型定义必须在模块类的初始化器中进行：__ Init __，而forward处理该模块的推理逻辑。您使用的pytorch层是模块 类 ，在用于推理之前需要初始化它们。与Keras这样的框架不同，Pytorch不需要汇编步骤，逻辑是声明定义的。

这是让您开始的事情：

class UNetlike(nn.Module):
    def __init__(self):
      super().__init__()
      
        self.c1 = nn.Sequential(self.conv2d_block(3, 16),
                                nn.MaxPool2d(kernel_size=2),
                                nn.Dropout2d(0.1))

        self.c2 = nn.Sequential(self.conv2d_block(16, 32),
                                nn.MaxPool2d(kernel_size=2),
                                nn.Dropout2d(0.1))
        

        self.c2 = nn.Sequential(self.conv2d_block(32, 64),
                                nn.MaxPool2d(kernel_size=2),
                                nn.Dropout2d(0.1))
        
        self.c4 = nn.Sequential(self.conv2d_block(64, 128),
                                nn.MaxPool2d(kernel_size=2),
                                nn.Dropout2d(0.1))
        
    def conv2d_block(self, in_channels, out_channels):
        return nn.Sequential(
            nn.Conv2d(in_channels=in_channels, out_channels=out_channels, 
                      kernel_size=3, padding="same"),
            nn.BatchNorm2d(out_channels),
            nn.ReLU(),
            nn.Conv2d(in_channels=out_channels, out_channels=out_channels, 
                      kernel_size=3, padding="same"),
            nn.BatchNorm2d(out_channels),
            nn.ReLU())
        
    def forward(self, x):
        p1 = self.c1(x)
        p2 = self.c2(p1)
        p3 = self.c3(p2)
        p4 = self.c3(p3)
        # so on and so forth