Struct Spheroid 

pub struct Spheroid {
    pub equatorial_radius: f64,
    pub flattening: f64,
}

Reference ellipsoid for geographic coordinate systems.

Field semantics match Boost’s srs::spheroid<T> (boost/geometry/srs/spheroid.hpp:49-112), except the second stored value is the flattening instead of the polar radius — the two forms are interconvertible via polar_radius / flattening but f is what the geodesic formulas actually take as input.

Examples

use geometry_cs::Spheroid;
let s = Spheroid::WGS84;
assert_eq!(s.equatorial_radius, 6_378_137.0);
// The WGS84 polar radius is ~6 356 752.3 m.
assert!((s.polar_radius() - 6_356_752.314_245).abs() < 0.01);

Fields

equatorial_radius: f64

Equatorial (semi-major) radius a, in metres.

flattening: f64

Flattening f = (a − b) / a, dimensionless.

Implementations

impl Spheroid

pub const WGS84: Self

The WGS84 reference ellipsoid.

Equatorial radius and flattening per the WGS84 defining parameters; matches the default-constructed srs::spheroid<RadiusType> in boost/geometry/srs/spheroid.hpp:62-69, which seeds m_a = 6_378_137.0 and m_b = 6_356_752.314_245_179_3.

pub fn polar_radius(&self) -> f64

Semi-minor axis b = a · (1 − f), in metres.

Counterpart to srs::spheroid<T>::get_radius<2>() in boost/geometry/srs/spheroid.hpp:78-92.

pub fn eccentricity_squared(&self) -> f64

First eccentricity squared e² = 2f − f².

Used by the geodesic strategies (Andoyer / Vincenty / Thomas) in boost/geometry/strategies/geographic/*.hpp. The identity e² = 2f − f² follows from b = a(1 − f) and e² = (a² − b²) / a².

Trait Implementations

impl Clone for Spheroid

fn clone(&self) -> Spheroid

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Spheroid

impl Debug for Spheroid

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

Formats the value using the given formatter.

impl PartialEq for Spheroid

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Spheroid