Function quest_bind::calc_expec_diagonal_op

pub fn calc_expec_diagonal_op(
    qureg: &Qureg<'_>,
    op: &DiagonalOp<'_>
) -> Result<Qcomplex, QuestError>

Computes the expected value of the diagonal operator op.

Since op is not necessarily Hermitian, the expected value may be a complex number.

Examples

let env = &QuestEnv::new();
let qureg =
    &mut Qureg::try_new(2, &env).expect("cannot allocate memory for Qureg");
let op = &mut DiagonalOp::try_new(2, env).unwrap();

init_diagonal_op(op, &[1., 2., 3., 4.], &[5., 6., 7., 8.]).unwrap();

let expec_val = calc_expec_diagonal_op(qureg, op).unwrap();

assert!((expec_val.re - 1.).abs() < EPSILON);
assert!((expec_val.im - 5.).abs() < EPSILON);

See QuEST API for more information.