torch.sqrt
torch.sqrt(input, *, out=None) -> Tensor
Returns a new tensor with the square-root of the elements of
   "input".
  \text{out}_{i} = \sqrt{\text{input}_{i}}

Parameters:
      input (Tensor) -- the input tensor.
Keyword Arguments:
      out (Tensor, optional) -- the output tensor.
Example:
  >>> a = torch.randn(4)
  >>> a
  tensor([-2.0755,  1.0226,  0.0831,  0.4806])
  >>> torch.sqrt(a)
  tensor([    nan,  1.0112,  0.2883,  0.6933])
