eclipticOfDate function

EclipticPosition eclipticOfDate(
  1. Vector3 direction,
  2. double distance,
  3. double jdTT, {
  4. Corrections corrections = const Corrections(),
})

Direction direction in the GCRS/ICRF frame as a position on the ecliptic of date jdTT (with nutation unless corrections turns it off).

Implementation

EclipticPosition eclipticOfDate(
  Vector3 direction,
  double distance,
  double jdTT, {
  Corrections corrections = const Corrections(),
}) {
  final t = centuriesSinceJ2000(jdTT);
  final ecliptic = gcrsToEclipticOfDate(
    direction,
    t,
    nutationInLongitude: corrections.nutation ? nutation(t).longitude : 0,
  );
  final longitude = math.atan2(ecliptic.y, ecliptic.x) * 180 / math.pi;
  return EclipticPosition(
    longitude < 0 ? longitude + 360 : longitude,
    math.asin(ecliptic.z.clamp(-1.0, 1.0)) * 180 / math.pi,
    distance,
  );
}