@Backend._assert_backend_available
def compute_hessian_vector_product(self, function, arguments):
    'Computes the directional derivative of the gradient, which is\n        equivalent to computing a Hessian-vector product with the direction\n        vector.\n        '
    if (len(arguments) == 1):
        (argument,) = arguments
        gradient = T.grad(function, argument)
        return self._compute_unary_hessian_vector_product(gradient, argument)
    gradients = T.grad(function, arguments)
    return self._compute_nary_hessian_vector_product(gradients, arguments)
Computes the directional derivative of the gradient, which is
equivalent to computing a Hessian-vector product with the direction
vector.
@Backend._assert_backend_available
def compute_hessian_vector_product(self, function, arguments):
    'Computes the directional derivative of the gradient, which is\n        equivalent to computing a Hessian-vector product with the direction\n        vector.\n        '
    if (len(arguments) == 1):
        (argument,) = arguments
        gradient = T.grad(function, argument)
        return self._compute_unary_hessian_vector_product(gradient, argument)
    gradients = T.grad(function, arguments)
    return self._compute_nary_hessian_vector_product(gradients, arguments)