cirq.SupportsTraceDistanceBound

An effect with known bounds on how easy it is to detect.

cirq.SupportsTraceDistanceBound(
    *args, **kwargs
)

Used when deciding whether or not an operation is negligible. For example, the trace distance between the states before and after a Z**0.00000001 operation is very close to 0, so it would typically be considered negligible.

Methods

_trace_distance_bound_

View source

_trace_distance_bound_() -> float

A maximum on the trace distance between val's input and output.

Generally this method is used when deciding whether to keep gates, so only the behavior near 0 is important. Approximations that overestimate the maximum trace distance are permitted. If, for any case, the bound exceeds 1, this function will return 1. Underestimates are not permitted.