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Super Kai (Kazuya Ito)
Super Kai (Kazuya Ito)

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flip in PyTorch

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*My post explains flipud().

flip() can get the 0D or more D tensor of reversed zero or more elements from the 0D or more D tensor of zero or more elements as shown below:

*Memos:

  • flip() can be used with torch or a tensor.
  • The 1st argument(input) with torch or using a tensor(Required-Type:tensor of int, float, complex or bool).
  • The 2nd argument with torch or the 1st or more arguments with a tensor are dims(Required-Type:int, tuple of int or list of int). *Each number must be unique.
import torch my_tensor = torch.tensor(2) # 0D tensor  torch.flip(input=my_tensor, dims=(0,)) my_tensor.flip(dims=(0,)) my_tensor.flip(0) torch.flip(input=my_tensor, dims=(-1,)) # tensor(2)  my_tensor = torch.tensor([2, 7, 4]) # 1D tensor  torch.flip(input=my_tensor, dims=(0,)) torch.flip(input=my_tensor, dims=(-1,)) # tensor([4, 7, 2])  my_tensor = torch.tensor([[2, 7, 4], [8, 3, 2]]) # 2D tensor  torch.flip(input=my_tensor, dims=(0,)) torch.flip(input=my_tensor, dims=(-2,)) # tensor([[8, 3, 2], [2, 7, 4]])  torch.flip(input=my_tensor, dims=(1,)) torch.flip(input=my_tensor, dims=(-1,)) # tensor([[4, 7, 2], [2, 3, 8]])  torch.flip(input=my_tensor, dims=(0, 1)) torch.flip(input=my_tensor, dims=(0, -1)) torch.flip(input=my_tensor, dims=(1, 0)) torch.flip(input=my_tensor, dims=(1, -2)) torch.flip(input=my_tensor, dims=(-1, 0)) torch.flip(input=my_tensor, dims=(-1, -2)) torch.flip(input=my_tensor, dims=(-2, 1)) torch.flip(input=my_tensor, dims=(-2, -1)) # tensor([[2, 3, 8], [4, 7, 2]])  my_tensor = torch.tensor([[[2, 7, 4], [8, 3, 2]], # 3D tensor  [[5, 0, 8], [3, 6, 1]]]) torch.flip(input=my_tensor, dims=(0,)) torch.flip(input=my_tensor, dims=(-3,)) # tensor([[[5, 0, 8], [3, 6, 1]], # [[2, 7, 4], [8, 3, 2]]])  torch.flip(input=my_tensor, dims=(1,)) torch.flip(input=my_tensor, dims=(-2,)) # tensor([[[8, 3, 2], [2, 7, 4]], # [[3, 6, 1], [5, 0, 8]]])  torch.flip(input=my_tensor, dims=(2,)) torch.flip(input=my_tensor, dims=(-1,)) # tensor([[[4, 7, 2], [2, 3, 8]], # [[8, 0, 5], [1, 6, 3]]])  torch.flip(input=my_tensor, dims=(0, 1)) torch.flip(input=my_tensor, dims=(0, -2)) torch.flip(input=my_tensor, dims=(1, 0)) torch.flip(input=my_tensor, dims=(1, -3)) torch.flip(input=my_tensor, dims=(-2, 0)) torch.flip(input=my_tensor, dims=(-2, -3)) torch.flip(input=my_tensor, dims=(-3, 1)) torch.flip(input=my_tensor, dims=(-3, -2)) # tensor([[[3, 6, 1], [5, 0, 8]], # [[8, 3, 2], [2, 7, 4]]])  torch.flip(input=my_tensor, dims=(0, 2)) torch.flip(input=my_tensor, dims=(0, -1)) torch.flip(input=my_tensor, dims=(2, 0)) torch.flip(input=my_tensor, dims=(2, -3)) torch.flip(input=my_tensor, dims=(-1, 0)) torch.flip(input=my_tensor, dims=(-1, -3)) torch.flip(input=my_tensor, dims=(-3, 2)) torch.flip(input=my_tensor, dims=(-3, -1)) # tensor([[[8, 0, 5], [1, 6, 3]], # [[4, 7, 2], [2, 3, 8]]])  torch.flip(input=my_tensor, dims=(1, 2)) torch.flip(input=my_tensor, dims=(1, -1)) torch.flip(input=my_tensor, dims=(2, 1)) torch.flip(input=my_tensor, dims=(2, -2)) torch.flip(input=my_tensor, dims=(-1, 1)) torch.flip(input=my_tensor, dims=(-1, -2)) torch.flip(input=my_tensor, dims=(-2, 2)) torch.flip(input=my_tensor, dims=(-2, -1)) # tensor([[[2, 3, 8], [4, 7, 2]], # [[1, 6, 3], [8, 0, 5]]])  torch.flip(input=my_tensor, dims=(0, 1, 2)) etc. # tensor([[[1, 6, 3], [8, 0, 5]], # [[2, 3, 8], [4, 7, 2]]])  my_tensor = torch.tensor([[[2., 7., 4.], [8., 3., 2.]], # 3D tensor  [[5., 0., 8.], [3., 6., 1.]]]) torch.flip(input=my_tensor, dims=(0,)) # tensor([[[5., 0., 8.], [3., 6., 1.]], # [[2., 7., 4.], [8., 3., 2.]]])  my_tensor = torch.tensor([[[2.+0.j, 7.+0.j, 4.+0.j], # 3D tensor  [8.+0.j, 3.+0.j, 2.+0.j]], [[5.+0.j, 0.+0.j, 8.+0.j], [3.+0.j, 6.+0.j, 1.+0.j]]]) torch.flip(input=my_tensor, dims=(0,)) # tensor([[[5.+0.j, 0.+0.j, 8.+0.j], # [3.+0.j, 6.+0.j, 1.+0.j]], # [[2.+0.j, 7.+0.j, 4.+0.j], # [8.+0.j, 3.+0.j, 2.+0.j]]])  # 3D tensor my_tensor = torch.tensor([[[True, False, True], [True, False, True]], [[False, True, False], [False, True, False]]]) torch.flip(input=my_tensor, dims=(0,)) # tensor([[[False, True, False], [False, True, False]], # [[True, False, True], [True, False, True]]]) 
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