[transpose][permute]维度转换

PyTorch提供了两个函数用于维度转换

• transpose
• permute

transpose

torch.transpose(input, dim0, dim1) → Tensor

函数transpose每次仅能调整两个维度

>>> import torch
>>> a = torch.arange(24).reshape(2, 3, 4)
>>> a.shape
torch.Size([2, 3, 4])
# 切换第1维和第2维
>>> torch.transpose(a, 1, 2).shape
torch.Size([2, 4, 3])
# 切换第0维和第2维
>>> torch.transpose(a, 2, 0).shape
torch.Size([4, 3, 2])

permute

permute(*dims) → Tensor

使用permute能够一次性调整多个维度

>>> import torch
>>> a = torch.arange(24).reshape(2, 3, 4)
>>> a.shape
torch.Size([2, 3, 4])
>>> a.permute(2, 0, 1).shape
torch.Size([4, 2, 3])