Note

This is the documentation for the current state of the development branch of Qiskit Experiments. The documentation or APIs here can change prior to being released.

LocalReadoutErrorAnalysis

class LocalReadoutErrorAnalysis[source]

Local readout error characterization analysis

Overview

This class generates the assignment matrices characterizing the readout error for each of the given qubits from the experiment result, and returns the resulting LocalReadoutMitigator

Each such matrix is a \(2\times 2\) matrix \(A\). Such that \(A_{y,x}\) is the probability to observe \(y\) given the true outcome should be \(x\), where \(x,y \in \left\{0,1\right\}\) can be 0 and 1.

In the experiment, two circuits are constructed - one for 0 outcome for all qubits and one for 1 outcome. From the observed results on the circuit, the probability for each \(x,y\) is determined, and \(A_{y,x}\) is set accordingly.

Analysis Results:
Analysis Figures:

  • (Optional) A figure of the assignment matrix. Note: producing this figure scales exponentially with the number of qubits.

References

[1] Sergey Bravyi, Sarah Sheldon, Abhinav Kandala, David C. Mckay, Jay M. Gambetta, Mitigating measurement errors in multi-qubit experiments, Phys. Rev. A 103, 042605 (2021), doi: 10.1103/PhysRevA.103.042605 (open)

Analysis options

These are the keyword arguments of the run() method.

Options

  • Defined in the class LocalReadoutErrorAnalysis:

    • plot (bool)

      Default value: False
      Set True to create figure for fit result.

    • ax (AxesSubplot)

      Default value: None
      Optional. A matplotlib axis object to draw.

  • Defined in the class BaseAnalysis:

    • figure_names (str or List[str])

      Default value: None
      Identifier of figures that appear in the experiment data to sort figures by name.

Initialization

Initialize the analysis object.

Attributes

options

Return the analysis options for run() method.

Methods

config()

Return the config dataclass for this analysis

Return type:

AnalysisConfig

copy()

Return a copy of the analysis

Return type:

BaseAnalysis

classmethod from_config(config)

Initialize an analysis class from analysis config

Return type:

BaseAnalysis

run(experiment_data, replace_results=False, **options)

Run analysis and update ExperimentData with analysis result.

Parameters:

  • experiment_data (ExperimentData) – the experiment data to analyze.

  • replace_results (bool) – If True clear any existing analysis results, figures, and artifacts in the experiment data and replace with new results. See note for additional information.

  • options – additional analysis options. See class documentation for supported options.

Returns:

An experiment data object containing analysis results, figures, and artifacts.

Raises:

QiskitError – If experiment_data container is not valid for analysis.

Return type:

ExperimentData

Note

Updating Results

If analysis is run with replace_results=True then any analysis results, figures, and artifacts in the experiment data will be cleared and replaced with the new analysis results. Saving this experiment data will replace any previously saved data in a database service using the same experiment ID.

If analysis is run with replace_results=False and the experiment data being analyzed has already been saved to a database service, or already contains analysis results or figures, a copy with a unique experiment ID will be returned containing only the new analysis results and figures. This data can then be saved as its own experiment to a database service.

set_options(**fields)

Set the analysis options for run() method.

Parameters:

fields – The fields to update the options