Struct Covariance 

pub struct Covariance { /* private fields */ }

The covariance of a spread of points on the ground, m². It serializes as its three entries and reads back through Covariance::new’s checks.

Implementations

impl Covariance

pub fn new( east_m2: f64, north_m2: f64, east_north_m2: f64, ) -> Result<Self, AnalysisError>

The covariance with the variances east_m2 and north_m2 and the covariance east_north_m2.

Errors

AnalysisError::Domain for an entry that isn’t finite, a negative variance, or a covariance larger than the variances allow (|east_north| > √east √north, so the matrix isn’t positive semi-definite), beyond four units of rounding: a covariance of points on a line, computed in floating point, can pass the bound by that much.

pub fn east_m2(&self) -> f64

The east variance, m².

pub fn north_m2(&self) -> f64

The north variance, m².

pub fn east_north_m2(&self) -> f64

The covariance of east and north, m².

pub fn principal_axes(&self) -> PrincipalAxes

The eigenvalues and the major axis’s heading (the module’s docs). The smaller eigenvalue is taken as (ac − b²)/λ₁, the determinant over the larger, rather than (a + c)/2 − √(…), whose subtraction loses every digit of a spread much narrower than it is long; it is cut at zero, since rounding can take the determinant just below for points on a line.

Trait Implementations

impl Clone for Covariance

fn clone(&self) -> Covariance

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Covariance

impl Debug for Covariance

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Covariance

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for Covariance

fn eq(&self, other: &Covariance) -> 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 Covariance

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 Covariance