mean function

({double axis, double ecc, double inc, double lon, double node, double peri}) mean(int p, double jde)

Mean orbital elements for planet p at jde.

Returns (lon, axis, ecc, inc, node, peri) where angular elements are in radians and axis is in AU.

Derived quantities:

• Mean anomaly M = lon - peri
• Argument of perihelion ω = peri - node

Implementation

({double lon, double axis, double ecc, double inc, double node, double peri})
    mean(int p, double jde) {
  final t = j2000Century(jde);
  final c = _cMean[p];
  return (
    lon: mod2pi(toRad(horner(t, c.l))),
    axis: horner(t, c.a),
    ecc: horner(t, c.e),
    inc: toRad(horner(t, c.i)),
    node: toRad(horner(t, c.n)),
    peri: toRad(horner(t, c.p)),
  );
}