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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/0.22/qiskit/algorithms/optimizers/aqgd.py" signature="AQGD(maxiter=1000, eta=1.0, tol=1e-06, momentum=0.25, param_tol=1e-06, averaging=10)" modifiers="class">
Bases: [`qiskit.algorithms.optimizers.optimizer.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** (`Union`\[`int`, `List`\[`int`]]) Maximum number of iterations (full gradient steps)
* **eta** (`Union`\[`float`, `List`\[`float`]]) The coefficient of the gradient update. Increasing this value results in larger step sizes: param = previous\_param - eta \* deriv
* **tol** (`float`) Tolerance for change in windowed average of objective values. Convergence occurs when either objective tolerance is met OR parameter tolerance is met.
* **momentum** (`Union`\[`float`, `List`\[`float`]]) Bias towards the previous gradient momentum in current update. Must be within the bounds: \[0,1)
* **param\_tol** (`float`) Tolerance for change in norm of parameters.
* **averaging** (`int`) Length of window over which to average objective values for objective convergence criterion
**Raises**
[**AlgorithmError**](qiskit.algorithms.AlgorithmError "qiskit.algorithms.AlgorithmError") If the length of `maxiter`, momentum\`, and `eta` is not the same.
## Methods
### get\_support\_level
<Function id="qiskit.algorithms.optimizers.AQGD.get_support_level" signature="AQGD.get_support_level()">
Support level dictionary
**Returns**
**gradient, bounds and initial point**
support information that is ignored/required.
**Return type**
Dict\[str, int]
</Function>
### gradient\_num\_diff
<Function id="qiskit.algorithms.optimizers.AQGD.gradient_num_diff" signature="AQGD.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*) the epsilon used in the numeric differentiation.
* **max\_evals\_grouped** (*int*) 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="AQGD.minimize(fun, x0, jac=None, bounds=None)">
Minimize the scalar function.
**Parameters**
* **fun** (`Callable`\[\[`Union`\[`float`, `ndarray`]], `float`]) The scalar function to minimize.
* **x0** (`Union`\[`float`, `ndarray`]) The initial point for the minimization.
* **jac** (`Optional`\[`Callable`\[\[`Union`\[`float`, `ndarray`]], `Union`\[`float`, `ndarray`]]]) The gradient of the scalar function `fun`.
* **bounds** (`Optional`\[`List`\[`Tuple`\[`float`, `float`]]]) Bounds for the variables of `fun`. This argument might be ignored if the optimizer does not support bounds.
**Return type**
[`OptimizerResult`](qiskit.algorithms.optimizers.OptimizerResult "qiskit.algorithms.optimizers.optimizer.OptimizerResult")
**Returns**
The result of the optimization, containing e.g. the result as attribute `x`.
</Function>
### print\_options
<Function id="qiskit.algorithms.optimizers.AQGD.print_options" signature="AQGD.print_options()">
Print algorithm-specific options.
</Function>
### set\_max\_evals\_grouped
<Function id="qiskit.algorithms.optimizers.AQGD.set_max_evals_grouped" signature="AQGD.set_max_evals_grouped(limit)">
Set max evals grouped
</Function>
### set\_options
<Function id="qiskit.algorithms.optimizers.AQGD.set_options" signature="AQGD.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*) options, given as name=value.
</Function>
### wrap\_function
<Function id="qiskit.algorithms.optimizers.AQGD.wrap_function" signature="AQGD.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*) the args to be injected
**Returns**
wrapper
**Return type**
function\_wrapper
</Function>
## 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">
**Return type**
`Dict`\[`str`, `Any`]
</Attribute>
</Class>