2115 pauli twirling callibration of expectation estimation shadow needs continue

[bdg221]

fixes #2115

Added continue to the case where f_val from the pauli twirling calibration is None.

This now prevents an additional mean value being incorrectly included for a particular split.

License

• I license this contribution under the terms of the GNU GPL, version 3 and grant Unitary Fund the right to provide additional permissions as described in section 7 of the GNU GPL, version 3.

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[codecov]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (7d05a9f) 98.21% compared to head (9384ced) 98.21%.
Report is 2 commits behind head on master.

Files	Patch %	Lines
mitiq/shadows/classical_postprocessing.py	66.66%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2116   +/-   ##
=======================================
  Coverage   98.21%   98.21%           
=======================================
  Files          87       87           
  Lines        4135     4135           
=======================================
  Hits         4061     4061           
  Misses         74       74           

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[andreamari]

Suggested change

	means.append(0.0)
	continue
	product = 0.0

Is this equivalent? If so, I would suggest using product = 0.0 since it makes the workflow more linear and easier to debug in the future.

If my suggestion doesn't work, I am fine with continue.

[bdg221]

That makes sense. Should a similar thing be done with the "else" on line 374 (when there aren't any matches between the measurement_outcome and the pauli_str expected outcomes.) That else would also include a product = 0.0 and at the end of the for loop do a single means.append(np.sum(product) / len(idxes))?

[andreamari]

Thanks @bdg221 !