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---
title: AQGD
description: API reference for qiskit.algorithms.optimizers.AQGD
in_page_toc_min_heading_level: 1
python_api_type: class
python_api_name: qiskit.algorithms.optimizers.AQGD
---
# AQGD
<Class id="qiskit.algorithms.optimizers.AQGD" isDedicatedPage={true} github="https://github.com/qiskit/qiskit/tree/stable/0.25/qiskit/algorithms/optimizers/aqgd.py" signature="qiskit.algorithms.optimizers.AQGD(maxiter=1000, eta=1.0, tol=1e-06, momentum=0.25, param_tol=1e-06, averaging=10)" modifiers="class">
Bases: [`Optimizer`](qiskit.algorithms.optimizers.Optimizer "qiskit.algorithms.optimizers.optimizer.Optimizer")
Analytic Quantum Gradient Descent (AQGD) with Epochs optimizer. Performs gradient descent optimization with a momentum term, analytic gradients, and customized step length schedule for parameterized quantum gates, i.e. Pauli Rotations. See, for example:
* K. Mitarai, M. Negoro, M. Kitagawa, and K. Fujii. (2018). Quantum circuit learning. Phys. Rev. A 98, 032309. [https://arxiv.org/abs/1803.00745](https://arxiv.org/abs/1803.00745)
* Maria Schuld, Ville Bergholm, Christian Gogolin, Josh Izaac, Nathan Killoran. (2019). Evaluating analytic gradients on quantum hardware. Phys. Rev. A 99, 032331. [https://arxiv.org/abs/1811.11184](https://arxiv.org/abs/1811.11184)
for further details on analytic gradients of parameterized quantum gates.
Gradients are computed “analytically” using the quantum circuit when evaluating the objective function.
Performs Analytical Quantum Gradient Descent (AQGD) with Epochs.
**Parameters**
* **maxiter** ([*int*](https://docs.python.org/3/library/functions.html#int "(in Python v3.12)") *|*[*list*](https://docs.python.org/3/library/stdtypes.html#list "(in Python v3.12)")*\[*[*int*](https://docs.python.org/3/library/functions.html#int "(in Python v3.12)")*]*) Maximum number of iterations (full gradient steps)
* **eta** ([*float*](https://docs.python.org/3/library/functions.html#float "(in Python v3.12)") *|*[*list*](https://docs.python.org/3/library/stdtypes.html#list "(in Python v3.12)")*\[*[*float*](https://docs.python.org/3/library/functions.html#float "(in Python v3.12)")*]*) The coefficient of the gradient update. Increasing this value results in larger step sizes: param = previous\_param - eta \* deriv
* **tol** ([*float*](https://docs.python.org/3/library/functions.html#float "(in Python v3.12)")) Tolerance for change in windowed average of objective values. Convergence occurs when either objective tolerance is met OR parameter tolerance is met.
* **momentum** ([*float*](https://docs.python.org/3/library/functions.html#float "(in Python v3.12)") *|*[*list*](https://docs.python.org/3/library/stdtypes.html#list "(in Python v3.12)")*\[*[*float*](https://docs.python.org/3/library/functions.html#float "(in Python v3.12)")*]*) Bias towards the previous gradient momentum in current update. Must be within the bounds: \[0,1)
* **param\_tol** ([*float*](https://docs.python.org/3/library/functions.html#float "(in Python v3.12)")) Tolerance for change in norm of parameters.
* **averaging** ([*int*](https://docs.python.org/3/library/functions.html#int "(in Python v3.12)")) Length of window over which to average objective values for objective convergence criterion
**Raises**
[**AlgorithmError**](algorithms#qiskit.algorithms.AlgorithmError "qiskit.algorithms.AlgorithmError") If the length of `maxiter`, momentum\`, and `eta` is not the same.
## Attributes
### bounds\_support\_level
<Attribute id="qiskit.algorithms.optimizers.AQGD.bounds_support_level">
Returns bounds support level
</Attribute>
### gradient\_support\_level
<Attribute id="qiskit.algorithms.optimizers.AQGD.gradient_support_level">
Returns gradient support level
</Attribute>
### initial\_point\_support\_level
<Attribute id="qiskit.algorithms.optimizers.AQGD.initial_point_support_level">
Returns initial point support level
</Attribute>
### is\_bounds\_ignored
<Attribute id="qiskit.algorithms.optimizers.AQGD.is_bounds_ignored">
Returns is bounds ignored
</Attribute>
### is\_bounds\_required
<Attribute id="qiskit.algorithms.optimizers.AQGD.is_bounds_required">
Returns is bounds required
</Attribute>
### is\_bounds\_supported
<Attribute id="qiskit.algorithms.optimizers.AQGD.is_bounds_supported">
Returns is bounds supported
</Attribute>
### is\_gradient\_ignored
<Attribute id="qiskit.algorithms.optimizers.AQGD.is_gradient_ignored">
Returns is gradient ignored
</Attribute>
### is\_gradient\_required
<Attribute id="qiskit.algorithms.optimizers.AQGD.is_gradient_required">
Returns is gradient required
</Attribute>
### is\_gradient\_supported
<Attribute id="qiskit.algorithms.optimizers.AQGD.is_gradient_supported">
Returns is gradient supported
</Attribute>
### is\_initial\_point\_ignored
<Attribute id="qiskit.algorithms.optimizers.AQGD.is_initial_point_ignored">
Returns is initial point ignored
</Attribute>
### is\_initial\_point\_required
<Attribute id="qiskit.algorithms.optimizers.AQGD.is_initial_point_required">
Returns is initial point required
</Attribute>
### is\_initial\_point\_supported
<Attribute id="qiskit.algorithms.optimizers.AQGD.is_initial_point_supported">
Returns is initial point supported
</Attribute>
### setting
<Attribute id="qiskit.algorithms.optimizers.AQGD.setting">
Return setting
</Attribute>
### settings
<Attribute id="qiskit.algorithms.optimizers.AQGD.settings" />
## Methods
### get\_support\_level
<Function id="qiskit.algorithms.optimizers.AQGD.get_support_level" signature="get_support_level()">
Support level dictionary
**Returns**
**gradient, bounds and initial point**
support information that is ignored/required.
**Return type**
Dict\[[str](https://docs.python.org/3/library/stdtypes.html#str "(in Python v3.12)"), [int](https://docs.python.org/3/library/functions.html#int "(in Python v3.12)")]
</Function>
### gradient\_num\_diff
<Function id="qiskit.algorithms.optimizers.AQGD.gradient_num_diff" signature="gradient_num_diff(x_center, f, epsilon, max_evals_grouped=None)" modifiers="static">
We compute the gradient with the numeric differentiation in the parallel way, around the point x\_center.
**Parameters**
* **x\_center** (*ndarray*) point around which we compute the gradient
* **f** (*func*) the function of which the gradient is to be computed.
* **epsilon** ([*float*](https://docs.python.org/3/library/functions.html#float "(in Python v3.12)")) the epsilon used in the numeric differentiation.
* **max\_evals\_grouped** ([*int*](https://docs.python.org/3/library/functions.html#int "(in Python v3.12)")) max evals grouped, defaults to 1 (i.e. no batching).
**Returns**
the gradient computed
**Return type**
grad
</Function>
### minimize
<Function id="qiskit.algorithms.optimizers.AQGD.minimize" signature="minimize(fun, x0, jac=None, bounds=None)">
Minimize the scalar function.
**Parameters**
* **fun** (*Callable\[\[POINT],* [*float*](https://docs.python.org/3/library/functions.html#float "(in Python v3.12)")*]*) The scalar function to minimize.
* **x0** (*POINT*) The initial point for the minimization.
* **jac** (*Callable\[\[POINT], POINT] | None*) The gradient of the scalar function `fun`.
* **bounds** ([*list*](https://docs.python.org/3/library/stdtypes.html#list "(in Python v3.12)")*\[*[*tuple*](https://docs.python.org/3/library/stdtypes.html#tuple "(in Python v3.12)")*\[*[*float*](https://docs.python.org/3/library/functions.html#float "(in Python v3.12)")*,* [*float*](https://docs.python.org/3/library/functions.html#float "(in Python v3.12)")*]] | None*) Bounds for the variables of `fun`. This argument might be ignored if the optimizer does not support bounds.
**Returns**
The result of the optimization, containing e.g. the result as attribute `x`.
**Return type**
[OptimizerResult](qiskit.algorithms.optimizers.OptimizerResult "qiskit.algorithms.optimizers.OptimizerResult")
</Function>
### print\_options
<Function id="qiskit.algorithms.optimizers.AQGD.print_options" signature="print_options()">
Print algorithm-specific options.
</Function>
### set\_max\_evals\_grouped
<Function id="qiskit.algorithms.optimizers.AQGD.set_max_evals_grouped" signature="set_max_evals_grouped(limit)">
Set max evals grouped
</Function>
### set\_options
<Function id="qiskit.algorithms.optimizers.AQGD.set_options" signature="set_options(**kwargs)">
Sets or updates values in the options dictionary.
The options dictionary may be used internally by a given optimizer to pass additional optional values for the underlying optimizer/optimization function used. The options dictionary may be initially populated with a set of key/values when the given optimizer is constructed.
**Parameters**
**kwargs** ([*dict*](https://docs.python.org/3/library/stdtypes.html#dict "(in Python v3.12)")) options, given as name=value.
</Function>
### wrap\_function
<Function id="qiskit.algorithms.optimizers.AQGD.wrap_function" signature="wrap_function(function, args)" modifiers="static">
Wrap the function to implicitly inject the args at the call of the function.
**Parameters**
* **function** (*func*) the target function
* **args** ([*tuple*](https://docs.python.org/3/library/stdtypes.html#tuple "(in Python v3.12)")) the args to be injected
**Returns**
wrapper
**Return type**
function\_wrapper
</Function>
</Class>