Hi, I am training a custom CNN, I need to use a linear activation function. but I didn’t find anything in pytorch. I khow this activation just pass the input to the output of it, so should I use `nn.Linear(nin, nin)`

or `nn.Identity()`

or do nothing?

while I am training my network, the training and validation is nearly constant and I think this is cause of bad usage of my activation functions

Here is my model:

and here is my code:

```
class Block(nn.Module):
def __init__(self, in_channels, out_channels, exp=1, stride=1, type=''):
super().__init__()
self.t = type
self.stride = stride
self.inc, self.outc = in_channels, out_channels
self.exp = exp
self.blockc = nn.Sequential(
nn.Conv2d(self.inc, self.inc* self.exp, kernel_size=1),
nn.ReLU6(inplace=True),
nn.Conv2d(self.inc * self.exp, self.inc * self.exp, kernel_size=3, groups= self.inc * self.exp, stride= self.stride, padding=1),
nn.ReLU6(inplace=True),
nn.Conv2d(self.inc * self.exp, self.outc, kernel_size=1),
nn.Identity())#,
def forward(self, x):
out = self.blockc(x)
if self.t == 'A':
out = torch.add(out,x)
return out
class Model(nn.Module):
def __init__(self):
super().__init__()
self.conv2d1 = nn.Conv2d(in_channels=1, out_channels=8, kernel_size=3,padding=1, stride=2)
self.r = nn.ReLU6()
self.stage1 = Block(8, 8, exp=1, stride=2, type='C')
self.stage2 = nn.Sequential(
Block(8, 16, exp=2, stride=2, type='C'),
Block(16, 16, exp=2, type='A'))
self.stage3 = nn.Sequential(
Block(16, 24, exp=2, stride=2, type='C'),
Block(24, 24, exp=2, type='A'))
self.post_block2 = Block(24, 32, exp=2, type='B')
self.fc = nn.Linear(128, 10)
def forward(self, x):
out = self.conv2d1(x)
out = self.r(out)
out = self.stage1(out)
out = self.stage2(out)
out = self.stage3(out)
out = self.post_block2(out)
out = out.view(-1, 128)
out = self.fc(out)
return out
```