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CompleteMeasFitter

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

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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

Parameters

  • results (Union[Result, List[Result]]) – 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.

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.


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

plot_calibration

CompleteMeasFitter.plot_calibration(ax=None, show_plot=True)

Plot the calibration matrix (2D color grid plot)

Parameters

  • show_plot (bool) – call plt.show()
  • ax (matplotlib.axes.Axes) – An optional Axes object to use for the plot

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=None)

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

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