89 lines
4.1 KiB
Plaintext
89 lines
4.1 KiB
Plaintext
---
|
||
title: Gradient
|
||
description: API reference for qiskit.opflow.gradients.Gradient
|
||
in_page_toc_min_heading_level: 1
|
||
python_api_type: class
|
||
python_api_name: qiskit.opflow.gradients.Gradient
|
||
---
|
||
|
||
# Gradient
|
||
|
||
<Class id="qiskit.opflow.gradients.Gradient" isDedicatedPage={true} github="https://github.com/qiskit/qiskit/tree/stable/0.24/qiskit/opflow/gradients/gradient.py" signature="Gradient(grad_method='param_shift', **kwargs)" modifiers="class">
|
||
Bases: [`GradientBase`](qiskit.opflow.gradients.GradientBase "qiskit.opflow.gradients.gradient_base.GradientBase")
|
||
|
||
Deprecated: Convert an operator expression to the first-order gradient.
|
||
|
||
<Admonition title="Deprecated since version 0.24.0" type="danger">
|
||
The class `qiskit.opflow.gradients.gradient.Gradient` is deprecated as of qiskit-terra 0.24.0. It will be removed no earlier than 3 months after the release date. For code migration guidelines, visit [https://qisk.it/opflow\_migration](https://qisk.it/opflow_migration).
|
||
</Admonition>
|
||
|
||
## Methods Defined Here
|
||
|
||
<span id="qiskit-opflow-gradients-gradient-convert" />
|
||
|
||
### convert
|
||
|
||
<Function id="qiskit.opflow.gradients.Gradient.convert" signature="Gradient.convert(operator, params=None)">
|
||
**Parameters**
|
||
|
||
* **operator** ([*OperatorBase*](qiskit.opflow.OperatorBase "qiskit.opflow.operator_base.OperatorBase")) – The operator we are taking the gradient of.
|
||
* **params** ([*ParameterVector*](qiskit.circuit.ParameterVector "qiskit.circuit.parametervector.ParameterVector") *|*[*ParameterExpression*](qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression") *| List\[*[*ParameterExpression*](qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression")*] | None*) – The parameters we are taking the gradient with respect to. If not explicitly passed, they are inferred from the operator and sorted by name.
|
||
|
||
**Returns**
|
||
|
||
An operator whose evaluation yields the Gradient.
|
||
|
||
**Raises**
|
||
|
||
* **ValueError** – If `params` contains a parameter not present in `operator`.
|
||
* **ValueError** – If `operator` is not parameterized.
|
||
|
||
**Return type**
|
||
|
||
[*OperatorBase*](qiskit.opflow.OperatorBase "qiskit.opflow.operator_base.OperatorBase")
|
||
</Function>
|
||
|
||
<span id="qiskit-opflow-gradients-gradient-get-gradient" />
|
||
|
||
### get\_gradient
|
||
|
||
<Function id="qiskit.opflow.gradients.Gradient.get_gradient" signature="Gradient.get_gradient(operator, params)">
|
||
Get the gradient for the given operator w\.r.t. the given parameters
|
||
|
||
**Parameters**
|
||
|
||
* **operator** ([*OperatorBase*](qiskit.opflow.OperatorBase "qiskit.opflow.operator_base.OperatorBase")) – Operator w\.r.t. which we take the gradient.
|
||
* **params** ([*ParameterExpression*](qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression") *|*[*ParameterVector*](qiskit.circuit.ParameterVector "qiskit.circuit.parametervector.ParameterVector") *| List\[*[*ParameterExpression*](qiskit.circuit.ParameterExpression "qiskit.circuit.parameterexpression.ParameterExpression")*]*) – Parameters w\.r.t. which we compute the gradient.
|
||
|
||
**Returns**
|
||
|
||
Operator which represents the gradient w\.r.t. the given params.
|
||
|
||
**Raises**
|
||
|
||
* **ValueError** – If `params` contains a parameter not present in `operator`.
|
||
* [**OpflowError**](qiskit.opflow.OpflowError "qiskit.opflow.OpflowError") – If the coefficient of the operator could not be reduced to 1.
|
||
* [**OpflowError**](qiskit.opflow.OpflowError "qiskit.opflow.OpflowError") – 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
|
||
* **Exception** – Unintended code is reached
|
||
* **MissingOptionalLibraryError** – jax not installed
|
||
|
||
**Return type**
|
||
|
||
[*OperatorBase*](qiskit.opflow.OperatorBase "qiskit.opflow.operator_base.OperatorBase")
|
||
</Function>
|
||
|
||
## Attributes
|
||
|
||
### grad\_method
|
||
|
||
<Attribute id="qiskit.opflow.gradients.Gradient.grad_method">
|
||
Returns `CircuitGradient`.
|
||
|
||
**Returns**
|
||
|
||
`CircuitGradient`.
|
||
</Attribute>
|
||
</Class>
|
||
|