Function vsop87::keplerian_elements_from_vsop87 [−] [src]

pub fn keplerian_elements_from_vsop87(a: f64, l: f64, k: f64, h: f64, q: f64, p: f64) -> (f64, f64, f64, f64, f64, f64)

Calculates the keplerian orbital elements from VSOP87

This function calculates the keplerian orbital elements from the VSOP87 solution (the heliocentric orbital elements). The parameters needed are the 6 variables returned by the VSOP87 function for a given planet. It returns, in order, a tuple with the keplerian orbital elements of the planet:

  • Eccentricity (e)
  • Semimajor axis (a), in AU
  • Inclination (i), in radians
  • Longitude of the ascending node (Ω), in radians
  • Longitude of the periapsis (ϖ), in radians
  • Mean longitude (L₀), in radians

Examples

use vsop87::*;

let (a, l, k, h, q, p) = vsop87::mercury(2451545.0);


let (a, e, i, lan, lper, l) = keplerian_elements_from_vsop87(a, l, k, h, q, p);

assert!(a > 0.387097 && a < 0.387099);
assert!(e > 0.205629 && e < 0.205631);
assert!(i > 0.122260 && i < 0.122261);
assert!(lan > 0.843525 && lan < 0.843527);
assert!(lper >  1.35183 && lper < 1.35185);
assert!(l > 4.40259 && l < 4.40261);