reduce_mean

reduce_mean(grouped)

Reduce grouped values by averaging (e.g. Trotter ham samples).

For EXPVALS results only. Each entry’s values may be scalars (the standard case — averaged arithmetically) or per-observable lists of equal length emitted by a multi-observable MeasurementStage postprocess (averaged element-wise so each observable’s mean is preserved). For PROBS / COUNTS histograms (bitstring→probability dicts) use reduce_merge_histograms() instead.

Raises:

TypeError – If a grouped value is a dict (a PROBS / COUNTS histogram), naming reduce_merge_histograms() as the fix.

Example:

>>> reduce_mean({(('circ', 0),): [1.0, 3.0]})
{(('circ', 0),): 2.0}
>>> reduce_mean({(('circ', 0),): [[1.0, 5.0], [3.0, 7.0]]})
{(('circ', 0),): [2.0, 6.0]}

Return type:

dict[Any, Any]