flatten() and unflatten() in PyTorch

flatten() can remove zero or more dimensions from a 0D or more D tensor as shown below:

*Memos:

• 
  flatten() can be called both from torch and a tensor.


• The 2nd argument(int) with torch or the 1st argument(int) with a tensor is start_dim which is the 1st dimension.


• The 3rd argument(int) with torch or the 2nd argument(int) with a tensor is end_dim which is the last dimension.


• 
  flatten() can make a 0D tensor a 1D tensor.


• Zero or more integers, floating-point …

dimensions flatten function memos pytorch tensor torch unflatten