Struct Scatter 

pub struct Scatter { /* private fields */ }

Points on the ground (east and north of the pad, m), sorted, and how many samples were tried. It serializes as those two, and reads back through Scatter::new’s checks.

Implementations

impl Scatter

pub const MAX_COORDINATE_M: f64 = 1e9

The largest distance east or north of the pad a point may have, m: 10⁹ m, 25 times round the Earth, and small enough that every square and sum of a scatter stays finite.

pub fn new( points: Vec<[f64; 2]>, attempted: usize, ) -> Result<Self, AnalysisError>

The scatter of points, each [east_m, north_m], from attempted samples (those that gave no point make up the difference).

Errors

• AnalysisError::Domain for a coordinate that isn’t finite, or is more than Scatter::MAX_COORDINATE_M from the pad.
• AnalysisError::Count for more points than samples.

pub fn attempted(&self) -> usize

The samples tried.

pub fn count(&self) -> usize

The samples that gave a point.

pub fn missing(&self) -> usize

The samples that gave no point: failed, or never landed.

pub fn points(&self) -> &[[f64; 2]]

The points, sorted by east, then north.

pub fn mean(&self) -> Option<[f64; 2]>

The mean point, x₀ + Σ(xᵢ − x₀)/n with x₀ the first; None with no points.

pub fn covariance(&self) -> Option<Covariance>

The sample covariance, Σ(dᵢ − d̄)(dᵢ − d̄)ᵀ/(n − 1) with dᵢ = xᵢ − x₀; None with fewer than two points.

pub fn ellipse(&self, level: f64) -> Result<Option<Ellipse>, AnalysisError>

The ellipse holding the share level of a normal spread with this scatter’s mean and covariance (gaussian_scale); None with fewer than two points.

Errors

AnalysisError::Domain for a level outside (0, 1).

pub fn prediction_ellipse( &self, level: f64, ) -> Result<Option<Ellipse>, AnalysisError>

The ellipse a new flight lands in with probability level, if the landings are normal, allowing for the mean and covariance being estimated from this scatter (prediction_scale); None with fewer than three points.

Errors

AnalysisError::Domain for a level outside (0, 1).

pub fn principal_axes(&self) -> Option<PrincipalAxes>

The scatter’s axes: the heading of its Covariance::principal_axes, and the variances as the mean squares of the points’ distances along and across that heading, Σ(uᵀdᵢ)²/(n − 1) with dᵢ a point less the mean. With the heading exact these are the eigenvalues, and an error δ in the heading moves them by only δ² (λ₁ − λ₂) (they are Rayleigh quotients). So a spread far narrower than it is long keeps its width, which the covariance’s three entries, each rounded to about ε λ₁, can’t carry. None with fewer than two points.

pub fn share_inside(&self, ellipse: &Ellipse) -> Option<Share>

Bounds on the share of the samples tried that landed inside or on ellipse (Share): a sample with no point counts as outside for low, inside for high. None with no samples tried.

Trait Implementations

impl Clone for Scatter

fn clone(&self) -> Scatter

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Scatter

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Scatter

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for Scatter

fn eq(&self, other: &Scatter) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for Scatter

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Scatter