GradientBase

class GradientBase(grad_method='param_shift', **kwargs)

Bases: qiskit.aqua.operators.gradients.derivative_base.DerivativeBase

Base class for first-order operator gradient.

Convert an operator expression to the first-order gradient.

Parameters

• grad_method (Union[str, CircuitGradient]) – The method used to compute the state/probability gradient. Can be either 'param_shift' or 'lin_comb' or 'fin_diff'. Ignored for gradients w.r.t observable parameters.

• kwargs (dict) – Optional parameters for a CircuitGradient

Raises

ValueError – If method != fin_diff and epsilon is not None.

Methods

convert	type operator OperatorBase
gradient_wrapper	Get a callable function which provides the respective gradient, Hessian or QFI for given parameter values.
parameter_expression_grad	Get the derivative of a parameter expression w.r.t.

Attributes

grad_method

Returns CircuitGradient.

Return type

CircuitGradient

Returns

CircuitGradient.