torch.acosh
torch.acosh(input, *, out=None) -> Tensor
Returns a new tensor with the inverse hyperbolic cosine of the
   elements of "input".
  \text{out}_{i} = \cosh^{-1}(\text{input}_{i})

Note:
 The domain of the inverse hyperbolic cosine is *[1, inf)* and
 values outside this range will be mapped to "NaN", except for *+
 INF* for which the output is mapped to *+ INF*.

Parameters:
      input (Tensor) -- the input tensor.
Keyword Arguments:
      out (Tensor, optional) -- the output tensor.
Example:
  >>> a = torch.randn(4).uniform_(1, 2)
  >>> a
  tensor([ 1.3192, 1.9915, 1.9674, 1.7151 ])
  >>> torch.acosh(a)
  tensor([ 0.7791, 1.3120, 1.2979, 1.1341 ])
