Struct ObservableExpectation 

pub struct ObservableExpectation {
    pub mean: f64,
    pub variance: Option<f64>,
    pub group_variances: Option<Vec<f64>>,
    pub std_error: Option<f64>,
    pub metadata: RunMetadata,
}

Weighted-observable expectation with the grouped-measurement variance.

Fields

mean: f64

<H> = sum_k c_k <P_k>, including identity-term constants.

variance: Option<f64>

Sum of per-group variances Var(H_g) = <H_g^2> - <H_g>^2, each exact in the output state. This is the variance of a grouped measurement estimate drawing one shot per commuting group; with S_g shots on group g the estimator variance is sum_g Var(H_g) / S_g. It equals Var(H) of the full operator only when one group covers every term, since cross-group covariances are excluded. None on a route that evaluates term by term without the grouped traversal.

group_variances: Option<Vec<f64>>

Per-group Var(H_g) in grouping order, the input to shot allocation.

std_error: Option<f64>

Standard error of mean when a sampling route estimated the per-term values, None for analytic routes.

metadata: RunMetadata

Trait Implementations

impl Clone for ObservableExpectation

fn clone(&self) -> ObservableExpectation

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ObservableExpectation

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.