torch.autograd.functional.vjp
torch.autograd.functional.vjp(func, inputs, v=None, create_graph=False, strict=False)
Function that computes the dot product between a vector "v" and the
   Jacobian of the given function at the point given by the inputs.
Parameters:
      * func (function) -- a Python function that takes Tensor
        inputs and returns a tuple of Tensors or a Tensor.
  * **inputs** (*tuple of Tensors** or **Tensor*) -- inputs to the
    function "func".

  * **v** (*tuple of Tensors** or **Tensor*) -- The vector for
    which the vector Jacobian product is computed.  Must be the
    same size as the output of "func". This argument is optional
    when the output of "func" contains a single element and (if it
    is not provided) will be set as a Tensor containing a single
    "1".

  * **create_graph** (*bool**, **optional*) -- If "True", both the
