torch小知识点

知识点

import torch

x = torch.Tensor([1, 2, 3, 4])  # torch.Tensor是默认的tensor类型（torch.FlaotTensor）的简称。

print('-' * 50)
print(x)  # tensor([1., 2., 3., 4.])
print(x.size())  # torch.Size([4])
print(x.dim())  # 1
print(x.numpy())  # [1. 2. 3. 4.]

print('-' * 50)
print(torch.unsqueeze(x, 0))  # tensor([[1., 2., 3., 4.]])
print(torch.unsqueeze(x, 0).size())  # torch.Size([1, 4])
print(torch.unsqueeze(x, 0).dim())  # 2
print(torch.unsqueeze(x, 0).numpy())  # [[1. 2. 3. 4.]]

print('-' * 50)
print(torch.unsqueeze(x, 1))
# tensor([[1.],
#         [2.],
#         [3.],
#         [4.]])
print(torch.unsqueeze(x, 1).size())  # torch.Size([4, 1])
print(torch.unsqueeze(x, 1).dim())  # 2

print('-' * 50)
print(torch.unsqueeze(x, -1))
# tensor([[1.],
#         [2.],
#         [3.],
#         [4.]])
print(torch.unsqueeze(x, -1).size())  # torch.Size([4, 1])
print(torch.unsqueeze(x, -1).dim())  # 2

print('-' * 50)
print(torch.unsqueeze(x, -2))  # tensor([[1., 2., 3., 4.]])
print(torch.unsqueeze(x, -2).size())  # torch.Size([1, 4])
print(torch.unsqueeze(x, -2).dim())  # 2