iqm.error_reduction_tools.readout_characterization.data_processing.compute_state_dependent_covariance#
- iqm.error_reduction_tools.readout_characterization.data_processing.compute_state_dependent_covariance(data)#
Compute fully state-dependent readout error correlations between qubit pairs.
Calculates covariances conditioned on the preparation states of both qubits. This captures the full joint error distribution P(measure_i, measure_j | prep_i, prep_j).
- Parameters:
data (CalibrationData) – Calibration data from
run_calibration_circuits().- Returns:
State-dependent covariance output.
- Return type:
Note
Computes 12 correlation types corresponding to all relevant error pair combinations: (2,0), (3,0), (2,1), (3,1), (0,2), (0,3), (1,2), (1,3), (2,2), (3,3), (2,3), (3,2). Excludes trivial (0,0), (0,1), (1,0), (1,1).