torch.nn.Linear() 理解

Posted 2022-11-26 gz153016

# -- coding: utf-8 --

import torch

x = torch.randn(128, 20)  # 输入的维度是（128，20）
m = torch.nn.Linear(20, 30)  # 20,30是指维度
output = m(x)# (128, 20)  (20, 30) -> (128, 30)

print('m.weight.shape:\\n ', m.weight.shape) # torch.Size([30, 20])
print('m.bias.shape:\\n', m.bias.shape) # torch.Size([30])
print('output.shape:\\n', output.shape) # torch.Size([128, 30])

# ans = torch.mm(input,torch.t(m.weight))+m.bias 等价于下面的
ans = torch.mm(x, m.weight.t()) + m.bias
# y = x.A(T) + b
print('ans.shape:\\n', ans.shape) # torch.Size([128, 30])

print(torch.equal(ans, output)) # # True


# m.weight.shape:
#   torch.Size([30, 20])
# m.bias.shape:
#  torch.Size([30])
# output.shape:
#  torch.Size([128, 30])
# ans.shape:
#  torch.Size([128, 30])
# True