qiskit.optimization.algorithms.GroverOptimizer¶

class GroverOptimizer(num_value_qubits, num_iterations=3, quantum_instance=None, converters=None, penalty=None)[source]¶

Uses Grover Adaptive Search (GAS) to find the minimum of a QUBO function.

Parameters

num_value_qubits (int) – The number of value qubits.
num_iterations (int) – The number of iterations the algorithm will search with no improvement.
quantum_instance (Union[BaseBackend, Backend, QuantumInstance, None]) – Instance of selected backend, defaults to Aer’s statevector simulator.
converters (Union[QuadraticProgramConverter, List[QuadraticProgramConverter], None]) – The converters to use for converting a problem into a different form. By default, when None is specified, an internally created instance of QuadraticProgramToQubo will be used.
penalty (Optional[float]) – The penalty factor used in the default QuadraticProgramToQubo converter

Raises

TypeError – When there one of converters is an invalid type.

__init__(num_value_qubits, num_iterations=3, quantum_instance=None, converters=None, penalty=None)[source]¶

Parameters

num_value_qubits (int) – The number of value qubits.
num_iterations (int) – The number of iterations the algorithm will search with no improvement.
quantum_instance (Union[BaseBackend, Backend, QuantumInstance, None]) – Instance of selected backend, defaults to Aer’s statevector simulator.
converters (Union[QuadraticProgramConverter, List[QuadraticProgramConverter], None]) – The converters to use for converting a problem into a different form. By default, when None is specified, an internally created instance of QuadraticProgramToQubo will be used.
penalty (Optional[float]) – The penalty factor used in the default QuadraticProgramToQubo converter

Raises

TypeError – When there one of converters is an invalid type.

Methods

`__init__`(num_value_qubits[, num_iterations, …])	type num_value_qubits `int`
`get_compatibility_msg`(problem)	Checks whether a given problem can be solved with this optimizer.
`is_compatible`(problem)	Checks whether a given problem can be solved with the optimizer implementing this method.
`solve`(problem)	Tries to solves the given problem using the grover optimizer.

Attributes

quantum_instance

The quantum instance to run the circuits.

get_compatibility_msg(problem)[source]¶

Checks whether a given problem can be solved with this optimizer.

Checks whether the given problem is compatible, i.e., whether the problem can be converted to a QUBO, and otherwise, returns a message explaining the incompatibility.

Parameters: problem (QuadraticProgram) – The optimization problem to check compatibility.
Return type: str
Returns: A message describing the incompatibility.

is_compatible(problem)¶

Checks whether a given problem can be solved with the optimizer implementing this method.

Parameters: problem (QuadraticProgram) – The optimization problem to check compatibility.
Return type: bool
Returns: Returns True if the problem is compatible, False otherwise.

property quantum_instance¶

The quantum instance to run the circuits.

Return type: QuantumInstance
Returns: The quantum instance used in the algorithm.

solve(problem)[source]¶

Tries to solves the given problem using the grover optimizer.

Runs the optimizer to try to solve the optimization problem. If the problem cannot be, converted to a QUBO, this optimizer raises an exception due to incompatibility.

Parameters

problem (QuadraticProgram) – The problem to be solved.

Return type

OptimizationResult

Returns

The result of the optimizer applied to the problem.

Raises

AttributeError – If the quantum instance has not been set.
QiskitOptimizationError – If the problem is incompatible with the optimizer.