qiskit.result.BaseReadoutMitigator.expectation_value

abstract BaseReadoutMitigator.expectation_value(data, diagonal, qubits=None, clbits=None, shots=None)

Calculate the expectation value of a diagonal Hermitian operator.

Parameters

• data (Counts) – Counts object to be mitigated.

• diagonal (Union[Callable, dict, str, ndarray]) – the diagonal operator. This may either be specified as a string containing I,Z,0,1 characters, or as a real valued 1D array_like object supplying the full diagonal, or as a dictionary, or as Callable.

• qubits (Optional[Iterable[int]]) – the physical qubits measured to obtain the counts clbits. If None these are assumed to be qubits [0, …, N-1] for N-bit counts.

• clbits (Optional[List[int]]) – Optional, marginalize counts to just these bits.

• shots (Optional[int]) – Optional, the total number of shots, if None shots will be calculated as the sum of all counts.

Returns

The mean and an upper bound of the standard deviation of operator expectation value calculated from the current counts.

Return type

Tuple[float, float]