*My post explains how to create and acceess a tensor.
dim() can get the number of dimensions from the 0D or more D tensor of zero or more elements as shown below:
*Memos:
import torch my_tensor = torch.tensor(-3) # 0D tensor my_tensor.dim() # 0 my_tensor = torch.tensor([-3, 7, -5, 2, 6, 3]) # 1D tensor my_tensor.dim() # 1 my_tensor[0].dim() # 0 my_tensor = torch.tensor([[-3, 7, -5], [2, 6, 3], # 2D tensor [8, 0, -1], [4, 9, -6]]) my_tensor.dim() # 2 my_tensor[0].dim() # 1 my_tensor[0][0].dim() # 0 my_tensor = torch.tensor([[[-3, 7], [-5, 2], [6, 3]], # 3D tensor [[8, 0], [-1, 4], [9, -6]], [[5, -2], [-7, 9], [1, 1]], [[6, -4], [0, -9], [3, 5]]]) my_tensor.dim() # 3 my_tensor[0].dim() # 2 my_tensor[0][0].dim() # 1 my_tensor[0][0][0].ndim # 0 size() can get a size from the 0D or more D tensor of zero or more elements as shown below:
*Memos:
-
size()can be used with a tensor but not withtorch. - The 1st argument with a tensor is
dim(Optional-Type:int). - shape is the alias of
dim().
import torch my_tensor = torch.tensor(-3) # 0D tensor my_tensor.size() # torch.Size([]) my_tensor = torch.tensor([-3, 7, -5, 2, 6, 3]) # 1D tensor my_tensor.size() # torch.Size([6]) my_tensor.size(dim=0) my_tensor.size(dim=-1) # 6 my_tensor[0].size() # torch.Size([]) my_tensor = torch.tensor([[-3, 7, -5], [2, 6, 3], # 2D tensor [8, 0, -1], [4, 9, -6]]) my_tensor.size() # torch.Size([4, 3]) my_tensor.size(dim=0) my_tensor.size(dim=-2) # 4 my_tensor.size(dim=1) my_tensor.size(dim=-1) my_tensor[0].size(dim=0) my_tensor[0].size(dim=-1) # 3 my_tensor[0].size() # torch.Size([3]) my_tensor[0][0].size() # torch.Size([]) my_tensor = torch.tensor([[[-3, 7], [-5, 2], [6, 3]], # 3D tensor [[8, 0], [-1, 4], [9, -6]], [[5, -2], [-7, 9], [1, 1]], [[6, -4], [0, -9], [3, 5]]]) my_tensor.size() # torch.Size([4, 3, 2]) my_tensor.size(dim=0) my_tensor.size(dim=-3) # 4 my_tensor.size(dim=1) my_tensor.size(dim=-2) my_tensor[0].size(dim=0) my_tensor[0].size(dim=-2) # 3 my_tensor.size(dim=2) my_tensor.size(dim=-1) my_tensor[0].size(dim=1) my_tensor[0].size(dim=-1) my_tensor[0][0].size(dim=0) my_tensor[0][0].size(dim=-1) # 2 my_tensor[0].size() # torch.Size([3, 2]) my_tensor[0][0].size() # torch.Size([2]) my_tensor[0][0][0].size() # torch.Size([]) item() can get a standard Python number from the 0D or more D tensor of only one element as shown below:
*Memos:
-
item()can be used with a tensor but not withtorch. - A tensor must be a scalar.
import torch my_tensor = torch.tensor(-3) # 0D tensor my_tensor = torch.tensor([-3]) # 1D tensor my_tensor = torch.tensor([[-3]]) # 2D tensor my_tensor = torch.tensor([[[-3]]]) # 3D tensor my_tensor.item() # -3 tolist() can get a standard Python number or list from the 0D or more D tensor of zero or more elements as shown below. *tolist() can be used with a tensor but not with torch:
import torch my_tensor = torch.tensor(-3) # 0D tensor my_tensor.tolist() # -3 my_tensor = torch.tensor([-3, 7, -5, 2, 6, 3]) # 1D tensor my_tensor.tolist() # [-3, 7, -5, 2, 6, 3] my_tensor[0].tolist() # -3 my_tensor = torch.tensor([[-3, 7, -5], [2, 6, 3], # 2D tensor [8, 0, -1], [4, 9, -6]]) my_tensor.tolist() # [[-3, 7, -5], [2, 6, 3], # [8, 0, -1], [4, 9, -6]] my_tensor[0].tolist() # [-3, 7, -5] my_tensor[0][0].tolist() # -3 my_tensor = torch.tensor([[[-3, 7], [-5, 2], [6, 3]], # 3D tensor [[8, 0], [-1, 4], [9, -6]], [[5, -2], [-7, 9], [1, 1]], [[6, -4], [0, -9], [3, 5]]]) my_tensor.tolist() # [[[-3, 7], [-5, 2], [6, 3]], # [[8, 0], [-1, 4], [9, -6]], # [[5, -2], [-7, 9], [1, 1]], # [[6, -4], [0, -9], [3, 5]]] my_tensor[0].tolist() # [[-3, 7], [-5, 2], [6, 3]] my_tensor[0][0].tolist() # [-3, 7] my_tensor[0][0][0].tolist() # -3 
Top comments (0)