---
title: DerivativeBase (v0.46)
description: API reference for qiskit.opflow.gradients.DerivativeBase in qiskit v0.46
source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit/0.46/qiskit.opflow.gradients.DerivativeBase
---

# DerivativeBase

*class* `qiskit.opflow.gradients.DerivativeBase`

[GitHub](https://github.com/qiskit/qiskit/tree/stable/0.46/qiskit/opflow/gradients/derivative_base.py)

Bases: [`ConverterBase`](/docs/api/qiskit/0.46/qiskit.opflow.converters.ConverterBase "qiskit.opflow.converters.converter_base.ConverterBase")

Deprecated: Base class for differentiating opflow objects.

Converter for differentiating opflow objects and handling things like properly differentiating combo\_fn’s and enforcing product rules when operator coefficients are parameterized.

This is distinct from CircuitGradient converters which use quantum techniques such as parameter shifts and linear combination of unitaries to compute derivatives of circuits.

CircuitGradient - uses quantum techniques to get derivatives of circuits DerivativeBase - uses classical techniques to differentiate opflow data structures

> **Deprecated since version 0.24.0**
>
> The class `qiskit.opflow.gradients.derivative_base.DerivativeBase` is deprecated as of qiskit-terra 0.24.0. It will be removed in the Qiskit 1.0 release. For code migration guidelines, visit [https://qisk.it/opflow\_migration](https://qisk.it/opflow_migration).

## Methods

### convert

*abstract* `convert(operator, params=None)`

**Parameters**

- **operator** ([*OperatorBase*](/docs/api/qiskit/0.46/qiskit.opflow.OperatorBase "qiskit.opflow.operator_base.OperatorBase")) – The operator we are taking the gradient, Hessian or QFI of
- **params** ([*ParameterVector*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterVector "qiskit.circuit.parametervector.ParameterVector")  *|*[*ParameterExpression*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression")  *|*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*ParameterExpression*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression")*] | None*) – The parameters we are taking the gradient, Hessian or QFI with respect to.

**Returns**

An operator whose evaluation yields the gradient, Hessian or QFI.

**Raises**

[**ValueError**](https://docs.python.org/3/library/exceptions.html#ValueError) – If `params` contains a parameter not present in `operator`.

**Return type**

[*OperatorBase*](/docs/api/qiskit/0.46/qiskit.opflow.OperatorBase "qiskit.opflow.operator_base.OperatorBase")

### gradient\_wrapper

`gradient_wrapper(operator, bind_params, grad_params=None, backend=None, expectation=None)`

Get a callable function which provides the respective gradient, Hessian or QFI for given parameter values. This callable can be used as gradient function for optimizers.

**Parameters**

- **operator** ([*OperatorBase*](/docs/api/qiskit/0.46/qiskit.opflow.OperatorBase "qiskit.opflow.operator_base.OperatorBase")) – The operator for which we want to get the gradient, Hessian or QFI.
- **bind\_params** ([*ParameterExpression*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression")  *|*[*ParameterVector*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterVector "qiskit.circuit.parametervector.ParameterVector")  *|*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*ParameterExpression*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression")*]*) – The operator parameters to which the parameter values are assigned.
- **grad\_params** ([*ParameterExpression*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression")  *|*[*ParameterVector*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterVector "qiskit.circuit.parametervector.ParameterVector")  *|*[*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*ParameterExpression*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression")*] |* [*Tuple*](https://docs.python.org/3/library/typing.html#typing.Tuple)*\[*[*ParameterExpression*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression")*,* [*ParameterExpression*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression")*] |* [*List*](https://docs.python.org/3/library/typing.html#typing.List)*\[*[*Tuple*](https://docs.python.org/3/library/typing.html#typing.Tuple)*\[*[*ParameterExpression*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression")*,* [*ParameterExpression*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression")*]] | None*) – The parameters with respect to which we are taking the gradient, Hessian or QFI. If grad\_params = None, then grad\_params = bind\_params
- **backend** ([*Backend*](/docs/api/qiskit/0.46/qiskit.providers.Backend "qiskit.providers.backend.Backend")  *|*[*QuantumInstance*](/docs/api/qiskit/0.46/qiskit.utils.QuantumInstance "qiskit.utils.quantum_instance.QuantumInstance") *| None*) – The quantum backend or QuantumInstance to use to evaluate the gradient, Hessian or QFI.
- **expectation** ([*ExpectationBase*](/docs/api/qiskit/0.46/qiskit.opflow.expectations.ExpectationBase "qiskit.opflow.expectations.expectation_base.ExpectationBase") *| None*) – The expectation converter to be used. If none is set then PauliExpectation() is used.

**Returns**

Function to compute a gradient, Hessian or QFI. The function takes an iterable as argument which holds the parameter values.

**Return type**

[*Callable*](https://docs.python.org/3/library/typing.html#typing.Callable)\[\[[*Iterable*](https://docs.python.org/3/library/typing.html#typing.Iterable)], [*ndarray*](https://numpy.org/doc/stable/reference/generated/numpy.ndarray.html#numpy.ndarray)]

### parameter\_expression\_grad

*static* `parameter_expression_grad(param_expr, param)`

Get the derivative of a parameter expression w\.r.t. the given parameter.

> **Deprecated since version 0.18.0**
>
> The method `qiskit.opflow.gradients.derivative_base.DerivativeBase.parameter_expression_grad()` is deprecated as of qiskit-terra 0.18.0. It will be removed in the Qiskit 1.0 release. Instead, use the ParameterExpression.gradient method.

**Parameters**

- **param\_expr** ([*ParameterExpression*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression")) – The Parameter Expression for which we compute the derivative
- **param** ([*ParameterExpression*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression")) – Parameter w\.r.t. which we want to take the derivative

**Returns**

ParameterExpression representing the gradient of param\_expr w\.r.t. param

**Return type**

[*ParameterExpression*](/docs/api/qiskit/0.46/qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression") | [float](https://docs.python.org/3/library/functions.html#float)