cirq.trace_distance_bound

cirq.trace_distance_bound(val: Any) → float

Returns a maximum on the trace distance between this effect’s input

and output. This method makes use of the effect’s _trace_distance_bound_

method to determine the maximum bound on the trace difference between

before and after the effect.

Parameters:val – The effect of which the bound should be calculated Returns:If val has a _trace_distance_bound_ method and its result is not NotImplemented, that result is returned. Otherwise, 1 is returned. Result is capped at a maximum of 1, even if the underlying function produces a result greater than 1.