torch.Tensor.put_
Tensor.put_(index, source, accumulate=False) -> Tensor
Copies the elements from "source" into the positions specified by
   "index". For the purpose of indexing, the "self" tensor is treated
   as if it were a 1-D tensor.
"index" and "source" need to have the same number of elements, but
   not necessarily the same shape.
If "accumulate" is "True", the elements in "source" are added to
   "self". If accumulate is "False", the behavior is undefined if
   "index" contain duplicate elements.
Parameters:
      * index (LongTensor) -- the indices into self
  * **source** (*Tensor*) -- the tensor containing values to copy
    from

  * **accumulate** (*bool*) -- whether to accumulate into self

Example:
  >>> src = torch.tensor([[4, 3, 5],
  ...                     [6, 7, 8]])
  >>> src.put_(torch.tensor([1, 3]), torch.tensor([9, 10]))
  tensor([[  4,   9,   5],
          [ 10,   7,   8]])
