Skip to main contentIBM Quantum Documentation
This page is from an old version of Qiskit SDK and does not exist in the latest version. We recommend you migrate to the latest version. See the release notes for more information.
Important

IBM Quantum Platform is moving and this version will be sunset on July 1. To get started on the new platform, read the migration guide.

qiskit.ignis.mitigation.TensoredMeasFitter

class TensoredMeasFitter(results, mit_pattern, substate_labels_list=None, circlabel='')

GitHub

Measurement correction fitter for a tensored calibration.

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

Parameters

  • results (Union[Result, List[Result]]) – the results of running the measurement calibration circuits. If this is None, the user will set calibration matrices later.
  • mit_pattern (List[List[int]]) – qubits to perform the measurement correction on, divided to groups according to tensors
  • substate_labels_list (Optional[List[List[str]]]) – for each calibration matrix, the labels of its rows and columns. If None, the labels are ordered lexicographically
  • circlabel (str) – if the qubits were labeled

Raises

ValueError – if the mit_pattern doesn’t match the substate_labels_list

__init__

__init__(results, mit_pattern, substate_labels_list=None, circlabel='')

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

Parameters

  • results (Union[Result, List[Result]]) – the results of running the measurement calibration circuits. If this is None, the user will set calibration matrices later.
  • mit_pattern (List[List[int]]) – qubits to perform the measurement correction on, divided to groups according to tensors
  • substate_labels_list (Optional[List[List[str]]]) – for each calibration matrix, the labels of its rows and columns. If None, the labels are ordered lexicographically
  • circlabel (str) – if the qubits were labeled

Raises

ValueError – if the mit_pattern doesn’t match the substate_labels_list


Methods

__init__(results, mit_pattern[, …])Initialize a measurement calibration matrix from the results of running the circuits returned by measurement_calibration_circuits.
add_data(new_results[, rebuild_cal_matrix])Add measurement calibration data
plot_calibration([cal_index, ax, show_plot])Plot one of the calibration matrices (2D color grid plot).
readout_fidelity([cal_index, label_list])Based on the results, output the readout fidelity, which is the average of the diagonal entries in the calibration matrices.

Attributes

cal_matricesReturn cal_matrices.
filterReturn a measurement filter using the cal matrices.
nqubitsReturn _qubit_list_sizes.
substate_labels_listReturn _substate_labels_list.

add_data

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

cal_matrices

Return cal_matrices.

filter

Return a measurement filter using the cal matrices.

nqubits

Return _qubit_list_sizes.

plot_calibration

plot_calibration(cal_index=0, ax=None, show_plot=True)

Plot one of the calibration matrices (2D color grid plot).

Parameters

  • cal_index (integer) – calibration matrix to plot
  • ax (matplotlib.axes) – settings for the graph
  • show_plot (bool) – call plt.show()

Raises

  • QiskitError – if _cal_matrices was not set.
  • ImportError – if matplotlib was not installed.

readout_fidelity

readout_fidelity(cal_index=0, label_list=None)

Based on the results, output the readout fidelity, which is the average of the diagonal entries in the calibration matrices.

Parameters

  • cal_index (integer) – readout fidelity for this index in _cal_matrices
  • label_list (list) – Returns the average fidelity over of the groups f states. In the form of a list of lists of states. If None, then each state used in the construction of the calibration matrices forms a group of size 1

Returns

The readout fidelity (assignment fidelity)

Return type

numpy.array

Raises

QiskitError – If the calibration matrix has not been set for the object.

Additional Information:

The on-diagonal elements of the calibration matrices are the probabilities of measuring state ‘x’ given preparation of state ‘x’.

substate_labels_list

Return _substate_labels_list.

Was this page helpful?
Report a bug or request content on GitHub.