Qiskit / qiskit-addon-utils / 19122675903

72%

push

github

Add new functions for post-processing error-mitigated samples (#122)

* copy `measurement_bases.py` from expval branch

* add `apply_postselect_mask()`

* add `apply_pec_signs`

* add `expectation_values` function

* remove `qubit_wise` kwarg

This should always be `True`.

* pauli convention in meas-basis subroutine

Update to match the "numeric values" column of the table in the `SparseObservable` docs:
https://quantum.cloud.ibm.com/docs/en/api/qiskit/qiskit.quantum_info.SparseObservable#mathematics

* update pauli convention in docstrings

* lint

* cleanup output type

return floats instead of numpy floats

* fix bug (min of empty tuple)

* fix/standardize arg ordering

* fix off-by-one indexing

* fix docstring

* cosmetic edits

* use `ddof=1` when averaging shots

* for now, replace incorrect variance with `nan`

* minor formatting

* fix broadcasting

* fix processing of zero observable

* fix ordering, and (for now) revert IZXY to IXZY

* fix case of no twirling axis

* Update expectation_values.py

* Fix typo bug (`meas_basis_idx` -> `meas_basis_axis`)

Co-authored-by: dekelmeirom <33314493+dekelmeirom@users.noreply.github.com>

* add `gamma_from_noisy_boxes` function

Takes a dict of noise models, a dict mapping boxes to noise models, and a dict containing the "local scales" info, and returns gamma for the noisy circuit.

* add kwarg `pec_gamma`

For now, `pec_gamma` can be either an `int` or `None`, as described in the docstring.

Eventually should probably allow passing an array, in case the value varies for different circuit configurations in the job.

* allow `meas_basis_axis = None`

For convenience, let default behavior handle case where there is only 1 measurement basis, and the input `bool_array` correspondingly does not have a measurement basis axis.

* "Raises" section in docstring

* fix: lint

* fix: also reshape optional arrays if meas_basis_axis=0

* update paulis sum

make sure paulis not being dropped if coefficients cancel ... (continued)

34 of 259 new or added lines in 7 files covered. (13.13%)

589 of 814 relevant lines covered (72.36%)

0.72 hits per line