def hindu_solar_longitude_at_or_after(lam, tee):
"""Return the moment of the first time at or after moment, tee
when Hindu solar longitude will be lam degrees."""
tau = tee + (HinduSolarDate.SIDEREAL_YEAR * (1 / 360) * mod(lam - HinduDate.solar_longitude(tee), 360))
a = max(tee, tau - 5)
b = tau +5
return invert_angular(HinduDate.solar_longitude, lam, a, b)
def lunar_day_at_or_after(cls, k, tee):
"""Return the time lunar_day (tithi) number, k, begins at or after
moment, tee. k can be fractional (for karanas)."""
phase = (k - 1) * 12
tau = tee + ((1/360) * mod(phase - cls.lunar_phase(tee), 360) * cls.SYNODIC_MONTH)
a = max(tee, tau - 2)
b = tau + 2
return invert_angular(cls.lunar_phase, phase, a, b)
def solar_longitude_after(cls, lam, tee):
"""Return the moment UT of the first time at or after moment, tee,
when the solar longitude will be lam degrees."""
rate = cls.MEAN_TROPICAL_YEAR / 360
tau = tee + rate * mod(lam - cls.solar_longitude(tee), 360)
a = max(tee, tau - 5)
b = tau + 5
return invert_angular(cls.solar_longitude, lam, a, b)
def lunar_phase_at_or_after(cls, phi, tee):
"""Return the moment UT of the next time at or after moment, tee,
when the lunar_phase is phi degrees."""
tau = (tee +
(cls.MEAN_SYNODIC_MONTH *
(1/360) *
mod(phi - cls.lunar_phase(tee), 360)))
a = max(tee, tau - 2)
b = tau + 2
return invert_angular(cls.lunar_phase, phi, a, b)
def lunar_phase_at_or_before(cls, phi, tee):
"""Return the moment UT of the last time at or before moment, tee,
when the lunar_phase was phi degrees."""
tau = (tee -
(cls.MEAN_SYNODIC_MONTH *
(1/360) *
mod(cls.lunar_phase(tee) - phi, 360)))
a = tau - 2
b = min(tee, tau +2)
return invert_angular(cls.lunar_phase, phi, a, b)