z_obs_stats_to_survival_statistics

forest.benchmarking.randomized_benchmarking.z_obs_stats_to_survival_statistics(expectations: Sequence[float], std_errs: Sequence[float], num_shots=None, obs_are_independent=False)

Convert expectations of the dim - 1 observables which are the nontrivial combinations of tensor products of I and Z into survival mean and variance, where survival is the all zeros outcome.

If dim > 2, i.e. there are more than 2 qubits, and the observable expectations were collected simultaneously on the same set of shot data then there will be covariance between the different observables; thus to calculate the survival variance we must include the contribution of the covariance, which requires knowledge of the number of shots.

Parameters:

• expectations –
• std_errs –
• num_shots – the number of shots used to estimate each expectation
• obs_are_independent –

Returns: