def minor_solar_term_on_or_after(cls, fixed_date):
"""Return moment (in Beijing) of the first Chinese minor solar
term (jieqi) on or after fixed date, 'fixed_date'. The minor terms
begin when the sun's longitude is an odd multiple of 15 degrees."""
s = Solar.solar_longitude(cls.midnight(fixed_date))
l = mod(30 * iceiling((s - 15) / 30) + 15, 360)
return cls.solar_longitude_on_or_after(l, fixed_date)
def major_solar_term_on_or_after(cls, fixed_date):
"""Return moment (in Beijing) of the first Chinese major
solar term (zhongqi) on or after fixed date, 'fixed_date'. The
major terms begin when the sun's longitude is a
multiple of 30 degrees."""
s = Solar.solar_longitude(cls.midnight(fixed_date))
l = mod(30 * iceiling(s / 30), 360)
return cls.solar_longitude_on_or_after(l, fixed_date)
def sine_offset(self, local_time, alpha):
"""Return sine of angle between position of sun at
local time tee and when its depression is alpha at location, location.
Out of range when it does not occur."""
phi = self.latitude
tee_prime = self.universal_from_local(local_time)
delta = Astro.declination(tee_prime, mpf(0), Solar.solar_longitude(tee_prime))
return ((tan_degrees(phi) * tan_degrees(delta)) +
(sin_degrees(alpha) / (cos_degrees(delta) *
cos_degrees(phi))))
def lunar_phase(cls, tee):
"""Return the lunar phase, as an angle in degrees, at moment tee.
An angle of 0 means a new moon, 90 degrees means the
first quarter, 180 means a full moon, and 270 degrees
means the last quarter."""
phi = mod(cls.lunar_longitude(tee) - Solar.solar_longitude(tee), 360)
t0 = cls.nth_new_moon(0)
n = iround((tee - t0) / cls.MEAN_SYNODIC_MONTH)
phi_prime = (360 *
mod((tee - cls.nth_new_moon(n)) / cls.MEAN_SYNODIC_MONTH, 1))
if abs(phi - phi_prime) > 180:
return phi_prime
else:
return phi
def new_year_on_or_before(cls, fixed_date):
"""Return fixed date of Future Bahai New Year on or
before fixed date, 'fixed_date'."""
approx = Solar.estimate_prior_solar_longitude(Astro.SPRING, cls.sunset_in_haifa(fixed_date))
return next_int(ifloor(approx) - 1, lambda day: Solar.solar_longitude(cls.sunset_in_haifa(day)) <= Astro.SPRING + 2)
def sidereal_solar_longitude(tee):
"""Return sidereal solar longitude at moment, tee."""
return mod(Solar.solar_longitude(tee) - Astro.precession(tee) + SIDEREAL_START, 360)
def ayanamsha(tee):
"""Return the difference between tropical and sidereal solar longitude."""
return Solar.solar_longitude(tee) - sidereal_solar_longitude(tee)
def new_year_on_or_before(cls, date):
"""Return the fixed date of Astronomical Persian New Year on or
before fixed date, date."""
approx = Solar.estimate_prior_solar_longitude(Astro.SPRING, cls.midday_in_tehran(date))
return next_int(ifloor(approx) - 1, lambda day: (Solar.solar_longitude(cls.midday_in_tehran(day)) <= (Astro.SPRING + 2)))
def current_minor_solar_term(cls, fixed_date):
"""Return last Chinese minor solar term (jieqi) before date, 'fixed_date'."""
s = Solar.solar_longitude(cls.location(fixed_date).universal_from_standard(fixed_date))
return amod(3 + quotient(s - 15, 30), 12)
def major_solar_term(cls, fixed_date):
"""Return last Chinese major solar term (zhongqi) before
fixed date, 'fixed_date'."""
s = Solar.solar_longitude(cls.location(fixed_date).universal_from_standard(fixed_date))
return amod(2 + quotient(int(s), 30), 12)
def winter_solstice_on_or_before(cls, fixed_date):
"""Return fixed date, in the Chinese zone, of winter solstice
on or before fixed date, 'fixed_date'."""
approx = Solar.estimate_prior_solar_longitude(Astro.WINTER, cls.midnight(fixed_date + 1))
return next_int(ifloor(approx) - 1, lambda day: Astro.WINTER < Solar.solar_longitude(cls.midnight(1 + day)))
def new_year_on_or_before(cls, date):
"""Return fixed date of French Revolutionary New Year on or
before fixed date, date."""
approx = Solar.estimate_prior_solar_longitude(Astro.AUTUMN, cls.midnight_in_paris(date))
return next_int(ifloor(approx) - 1, lambda day: Astro.AUTUMN <= Solar.solar_longitude(cls.midnight_in_paris(day)))
