forest.benchmarking.tomography.pgdb_process_estimate(results: List[forest.benchmarking.observable_estimation.ExperimentResult], qubits: List[int], trace_preserving=True) → numpy.ndarray

Provide an estimate of the process via Projected Gradient Descent with Backtracking [PGD].

[PGD]Maximum-likelihood quantum process tomography via projected gradient descent. Knee et al. Phys. Rev. A 98, 062336 (2018).
  • results – A tomographically complete list of ExperimentResults
  • qubits – A list of qubits giving the tensor order of the resulting Choi matrix.
  • trace_preserving – Whether to project the estimate to a trace-preserving process. If set to False, we ensure trace non-increasing.

an estimate of the process in the Choi matrix representation.