pub fn eccentricity_from_apsides(
periapsis_radius: f64,
apoapsis_radius: f64,
) -> Option<f64>Expand description
Computes eccentricity from periapsis and apoapsis radii.
Formula: e = (r_a - r_p) / (r_a + r_p)
Returns None when either radius is less than or equal to zero, when apoapsis_radius is
less than periapsis_radius, or when the input or result is not finite.