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CompleteMeasFitter

class CompleteMeasFitter(results, state_labels, qubit_list=None, circlabel='')

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Bases: object

Measurement correction fitter for a full calibration

Initialize a measurement calibration matrix from the results of running the circuits returned by measurement_calibration_circuits

A wrapper for the tensored fitter

Warning

This class is not a public API. The internals are not stable and will likely change. It is used solely for the measurement_error_mitigation_cls kwarg of the QuantumInstance class’s constructor (as a class not an instance). Anything outside of that usage does not have the normal user-facing API stability.

Parameters

  • results – the results of running the measurement calibration circuits. If this is None the user will set a calibration matrix later.
  • state_labels (List[str]) – list of calibration state labels returned from measurement_calibration_circuits. The output matrix will obey this ordering.
  • qubit_list (Optional[List[int]]) – List of the qubits (for reference and if the subset is needed). If None, the qubit_list will be created according to the length of state_labels[0].
  • circlabel (str) – if the qubits were labeled.

Methods

add_data

CompleteMeasFitter.add_data(new_results, rebuild_cal_matrix=True)

Add measurement calibration data

Parameters

  • new_results (list or qiskit.result.Result) – a single result or list of result objects.
  • rebuild_cal_matrix (bool) – rebuild the calibration matrix

readout_fidelity

CompleteMeasFitter.readout_fidelity(label_list=None)

Based on the results, output the readout fidelity which is the normalized trace of the calibration matrix

Parameters

label_list (bool) – If None, returns the average assignment fidelity of a single state. Otherwise it returns the assignment fidelity to be in any one of these states averaged over the second index.

Returns

readout fidelity (assignment fidelity)

Return type

numpy.array

Additional Information:

The on-diagonal elements of the calibration matrix are the probabilities of measuring state ‘x’ given preparation of state ‘x’ and so the normalized trace is the average assignment fidelity

subset_fitter

CompleteMeasFitter.subset_fitter(qubit_sublist)

Return a fitter object that is a subset of the qubits in the original list.

Parameters

qubit_sublist (list) – must be a subset of qubit_list

Returns

A new fitter that has the calibration for a

subset of qubits

Return type

CompleteMeasFitter

Raises

QiskitError – If the calibration matrix is not initialized


Attributes

cal_matrix

Return cal_matrix.

filter

Return a measurement filter using the cal matrix.

qubit_list

Return list of qubits.

state_labels

Return state_labels.

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