Method: When::Ephemeris::Datum#equation_of_time

Defined in:

lib/when_exe/ephemeris.rb

#equation_of_time(t) ⇒ Numeric

均時差 / DAY

Parameters:

• t (Numeric) —

  ユリウス日(Terrestrial Time)

• t (When::TM::TemporalPosition)

Returns:

• (Numeric)

# File 'lib/when_exe/ephemeris.rb', line 1061

def equation_of_time(t)
  t = +t
  c = julian_century_from_2000(t)
  coords = _coords(t)
  coords = coords.rotate_z(0.5 - (@aberration||0) / coords.radius / 360)
  coords = coords.y_to_r(t, self)
  return 0.5 - ((coords.phi - (@sid[0] + c * (@sid[1] + c * @sid[2])) / 24.0) % 1)
end