qiskit.aqua.operators.gradients.Hessian.get_hessian

Hessian.get_hessian(operator, params=None)

Get the Hessian for the given operator w.r.t. the given parameters

Parameters

• operator (OperatorBase) – Operator w.r.t. which we take the Hessian.

• params (Union[Tuple[ParameterExpression, ParameterExpression], List[Tuple[ParameterExpression, ParameterExpression]], None]) – Parameters w.r.t. which we compute the Hessian.

Return type

OperatorBase

Returns

Operator which represents the gradient w.r.t. the given params.

Raises

• ValueError – If params contains a parameter not present in operator.

• AquaError – If the coefficient of the operator could not be reduced to 1. AquaError: If the differentiation of a combo_fn requires JAX but the package is not installed.

• TypeError – If the operator does not include a StateFn given by a quantum circuit

• TypeError – If the parameters were given in an unsupported format.

• Exception – Unintended code is reached