def lunar_altitude(self, tee):
"""Return the geocentric altitude of moon at moment, tee,
at location, location, as a small positive/negative angle in degrees,
ignoring parallax and refraction. Adapted from 'Astronomical
Algorithms' by Jean Meeus, Willmann_Bell, Inc., 1998."""
lamb = Lunar.lunar_longitude(tee)
beta = Lunar.lunar_latitude(tee)
alpha = Astro.right_ascension(tee, beta, lamb)
delta = Astro.declination(tee, beta, lamb)
theta0 = Astro.sidereal_from_moment(tee)
cap_H = mod(theta0 + self.longitude - alpha, 360)
altitude = arcsin_degrees(
(sin_degrees(self.latitude) * sin_degrees(delta)) +
(cos_degrees(self.latitude) * cos_degrees(delta) * cos_degrees(cap_H)))
return mod(altitude + 180, 360) - 180
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 local_from_apparent(self, tee):
"""Return local time from sundial time tee at location, location."""
return tee - Astro.equation_of_time(self.universal_from_local(tee))
def apparent_from_local(self, local_time):
"""Return sundial time from local time at this location."""
return local_time + Astro.equation_of_time(self.universal_from_local(local_time))
def universal_from_local(self, local_time):
"""Return universal time from local time at this location."""
return local_time - Astro.zone_from_longitude(self.longitude)
def sidereal_lunar_longitude(tee):
"""Return sidereal lunar longitude at moment, tee."""
return mod(Lunar.lunar_longitude(tee) - Astro.precession(tee) + SIDEREAL_START, 360)
return ifloor(mod((HinduSolarDate.longitude(date) + HinduLunarDate.longitude(date)) / angle(0, 800, 0), 27)) + 1
def sacred_wednesdays(g_year):
"""Return the list of Wednesdays in Gregorian year, g_year,
that are day 8 of Hindu lunar months."""
return sacred_wednesdays_in_range(GregorianDate.year_range(g_year))
def sacred_wednesdays_in_range(range):
"""Return the list of Wednesdays within range of dates
that are day 8 of Hindu lunar months."""
a = range[0]
b = range[1]
wed = DayOfWeek.Wednesday.on_or_after(a)
h_date = HinduLunarDate.from_fixed(wed)
ell = [wed] if (h_date.day == 8) else []
if is_in_range(wed, range):
ell[:0] = sacred_wednesdays_in_range([wed + 1, b])
return ell
else:
return []
SIDEREAL_START = Astro.precession(HinduDate.UJJAIN.universal_from_local(mesha_samkranti(JulianDate.ce(285))))
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 sidereal_lunar_longitude(tee):
"""Return sidereal lunar longitude at moment, tee."""
return mod(Lunar.lunar_longitude(tee) - Astro.precession(tee) + SIDEREAL_START, 360)