qiskit.aqua.QuantumInstance

__init__(backend, shots=1024, seed_simulator=None, max_credits=10, basis_gates=None, coupling_map=None, initial_layout=None, pass_manager=None, seed_transpiler=None, optimization_level=None, backend_options=None, noise_model=None, timeout=None, wait=5.0, skip_qobj_validation=True, measurement_error_mitigation_cls=None, cals_matrix_refresh_period=30, measurement_error_mitigation_shots=None, job_callback=None)

Quantum Instance holds a Qiskit Terra backend as well as configuration for circuit transpilation and execution. When provided to an Aqua algorithm the algorithm will execute the circuits it needs to run using the instance.

Parameters

• backend (Union[Backend, BaseBackend]) – Instance of selected backend
• shots (int) – Number of repetitions of each circuit, for sampling
• seed_simulator (Optional[int]) – Random seed for simulators
• max_credits (int) – Maximum credits to use
• basis_gates (Optional[List[str]]) – List of basis gate names supported by the target. Defaults to basis gates of the backend.
• coupling_map (Union[CouplingMap, List[List], None]) – Coupling map (perhaps custom) to target in mapping
• initial_layout (Union[Layout, Dict, List, None]) – Initial layout of qubits in mapping
• pass_manager (Optional[PassManager]) – Pass manager to handle how to compile the circuits
• seed_transpiler (Optional[int]) – The random seed for circuit mapper
• optimization_level (Optional[int]) – How much optimization to perform on the circuits. Higher levels generate more optimized circuits, at the expense of longer transpilation time.
• backend_options (Optional[Dict]) – All running options for backend, please refer to the provider of the backend for information as to what options it supports.
• noise_model (Optional[NoiseModel]) – noise model for simulator
• timeout (Optional[float]) – Seconds to wait for job. If None, wait indefinitely.
• wait (float) – Seconds between queries for job result
• skip_qobj_validation (bool) – Bypass Qobj validation to decrease circuit processing time during submission to backend.
• measurement_error_mitigation_cls (Optional[Callable]) – The approach to mitigate measurement errors. Qiskit Ignis provides fitter classes for this functionality and CompleteMeasFitter from qiskit.ignis.mitigation.measurement module can be used here. (TensoredMeasFitter is not supported).
• cals_matrix_refresh_period (int) – How often to refresh the calibration matrix in measurement mitigation. in minutes
• measurement_error_mitigation_shots (Optional[int]) – The number of shots number for building calibration matrix. If None, the main shots parameter value is used.
• job_callback (Optional[Callable]) – Optional user supplied callback which can be used to monitor job progress as jobs are submitted for processing by an Aqua algorithm. The callback is provided the following arguments: job_id, job_status, queue_position, job

Raises

• AquaError – the shots exceeds the maximum number of shots
• AquaError – set noise model but the backend does not support that
• AquaError – set backend_options but the backend does not support that

assemble(circuits)

assemble circuits

Return type

Qobj

Return BaseBackend backend object.

Getter of backend_config.

Return backend name.

Getter of backend_options.

cals_matrix(qubit_index=None)

Get the stored calibration matrices and its timestamp.

Parameters

qubit_index (Optional[List[int]]) – the qubit index of corresponding calibration matrix. If None, return all stored calibration matrices.

Return type

Union[Tuple[ndarray, float], Dict[str, Tuple[ndarray, float]], None]

Returns

The calibration matrix and the creation timestamp if qubit_index is not None otherwise, return all matrices and their timestamp in a dictionary.

returns matrix refresh period

Getter of circuit summary.

Getter of compile_config.

execute(circuits, had_transpiled=False)

A wrapper to interface with quantum backend.

Parameters

• circuits (Union[QuantumCircuit, List[QuantumCircuit]]) – circuits to execute
• had_transpiled (bool) – whether or not circuits had been transpiled

Return type

Result

Returns

Result object

TODO: Maybe we can combine the circuits for the main ones and calibration circuits before

assembling to the qobj.

Return True if backend is a local backend.

Return True if backend is a simulator.

Return True if backend is a statevector-type simulator.

maybe_refresh_cals_matrix(timestamp=None)

Calculate the time difference from the query of last time.

Parameters

timestamp (Optional[float]) – timestamp

Return type

bool

Returns

Whether or not refresh the cals_matrix

returns measurement error mitigation cls

returns measurement error mitigation shots

Getter of noise_config.

Getter of qjob_config.

reset_execution_results()

Reset execution results

Return type

None

Getter of run_config.

set_config(**kwargs)

Set configurations for the quantum instance.

checks if skip qobj validation

Accumulated time taken for execution.

Return type

float

transpile(circuits)

A wrapper to transpile circuits to allow algorithm access the transpiled circuits. :type circuits: Union[QuantumCircuit, List[QuantumCircuit]] :param circuits: circuits to transpile

Return type

List[QuantumCircuit]

Returns

The transpiled circuits, it is always a list even though the length is one.