def equinox_solstice():
lookup_table = [
'VE',
'SS',
'AE',
'WS',
]
start = datetime.today().astimezone().replace(month=1,
day=1,
hour=0,
minute=0,
second=0,
microsecond=0)
end = datetime.today().astimezone().replace(month=12,
day=31,
hour=0,
minute=0,
second=0,
microsecond=0)
today = datetime.today().astimezone()
t0 = ts.utc(start)
t1 = ts.utc(end)
times, events = almanac.find_discrete(t0, t1, almanac.seasons(ephem))
tz = datetime.now().astimezone().tzinfo
for yi, ti in zip(events, times):
ti = ti.astimezone(tz)
if (today.month, today.day) == (ti.month, ti.day):
return lookup_table[yi] + ti.strftime('%H%M')
return ''
def test_close_start_and_end():
ts = api.load.timescale()
t0 = ts.utc(2018, 9, 23, 1)
t1 = ts.utc(2018, 9, 23, 2)
e = api.load('de421.bsp')
t, y = almanac.find_discrete(t0, t1, almanac.seasons(e))
strings = t.utc_strftime('%Y-%m-%d %H:%M')
assert strings == ['2018-09-23 01:54']
def test_close_start_and_end():
ts = api.load.timescale()
t0 = ts.utc(2018, 9, 23, 1)
t1 = ts.utc(2018, 9, 23, 2)
e = api.load('de421.bsp')
t, y = almanac.find_discrete(t0, t1, almanac.seasons(e))
t.tt += half_minute
strings = t.utc_strftime('%Y-%m-%d %H:%M')
assert strings == ['2018-09-23 01:54']
def test_seasons():
ts = api.load.timescale()
t0 = ts.utc(2018, 9, 20)
t1 = ts.utc(2018, 12, 31)
e = api.load('de421.bsp')
t, y = almanac.find_discrete(t0, t1, almanac.seasons(e))
strings = t.utc_strftime('%Y-%m-%d %H:%M')
print(strings)
assert strings == ['2018-09-23 01:54', '2018-12-21 22:23']
assert (y == (2, 3)).all()
def march_equinox(year):
# must be 15 day range minimum, apparently?
t0 = ts.utc(year, 3, 13)
t1 = ts.utc(year, 3, 28)
tstamp, phase = almanac.find_discrete(t0, t1, almanac.seasons(e))
for phi, ti in zip(phase, tstamp):
if phi == 0:
return ti.utc_datetime()
else:
raise ExceptionalError("Is this Earth?")
def season_event_times(start, end):
"""
Computes season event times between start and end.
Returns list of EventTime objects.
"""
t, y = almanac.find_discrete(start, end, almanac.seasons(ephemeris))
return [
EventTime(Event(event, almanac.SEASON_EVENTS[event]), time)
for time, event in zip(t, y)
]
def test_seasons():
ts = api.load.timescale()
t0 = ts.utc(2018, 9, 20)
t1 = ts.utc(2018, 12, 31)
e = api.load('de421.bsp')
t, y = almanac.find_discrete(t0, t1, almanac.seasons(e))
t.tt += half_minute
strings = t.utc_strftime('%Y-%m-%d %H:%M')
print(strings)
assert strings == ['2018-09-23 01:54', '2018-12-21 22:23']
assert (y == (2, 3)).all()
def getSeason( n, season ):
'''Returns the date of the season for year n.'''
from skyfield import almanac
loadAstronomyData( )
if not g.astroDataAvailable:
raise ValueError( "Astronomy functions are unavailable." )
t, y = almanac.find_discrete( g.timescale.utc( real_int( n ), 1, 1 ),
g.timescale.utc( n, 12, 31 ), almanac.seasons( g.ephemeris ) )
result = RPNDateTime.parseDateTime( t[ season ].utc_datetime( ) )
return result.getLocalTime( )
def get_seasons(timezone_name, year):
ts = api.load.timescale(builtin=True)
load = api.Loader('/var/data')
eph = load('de430t.bsp')
localtz = timezone(timezone_name)
t0 = ts.utc(year) # midnight Jan 1
t1 = ts.utc(year + 1) # midnight Jan 1 following year
t, y = almanac.find_discrete(t0, t1, almanac.seasons(eph))
season = {}
for yi, ti in zip(y, t):
season[almanac.SEASON_EVENTS[yi]] = ti.utc_datetime().astimezone(localtz)
eph.close()
return season
def calculate_equinoxes(year, timezone='UTC'):
""" calculate equinox with time zone """
tz = pytz.timezone(timezone)
load = Loader(get_skyfield_data_path())
ts = load.timescale()
planets = load('de421.bsp')
t0 = ts.utc(year, 1, 1)
t1 = ts.utc(year, 12, 31)
datetimes, _ = almanac.find_discrete(t0, t1, almanac.seasons(planets))
vernal_equinox = datetimes[0].astimezone(tz).date()
autumn_equinox = datetimes[2].astimezone(tz).date()
return vernal_equinox, autumn_equinox
def getSeason( n, season ):
'''Returns the date of the season for year n.'''
loadAstronomyData( )
if isinstance( n, RPNDateTime ):
n = n.year
if not g.astroDataAvailable:
raise ValueError( 'Astronomy functions are unavailable.' )
times, _ = almanac.find_discrete( g.timescale.utc( n, 1, 1 ),
g.timescale.utc( n, 12, 31 ), almanac.seasons( g.ephemeris ) )
result = RPNDateTime.parseDateTime( times[ season ].utc_datetime( ) )
return result.getLocalTime( )
def vernal_equinox(data: AstroData, year: int) -> Time:
"""
For a given year find the date of the vernal equinox
"""
before = data.timescale.julian_calendar_cutoff
data.timescale.julian_calendar_cutoff = None
t0 = data.timescale.ut1(year, 3, 16)
t1 = data.timescale.ut1(year, 3, 26)
data.timescale.julian_calendar_cutoff = before
times, types = almanac.find_discrete(t0, t1,
almanac.seasons(data.ephemeris))
assert len(times) == 1
assert almanac.SEASON_EVENTS[(types[0])] == 'Vernal Equinox'
return times[0]
def get_seasons(year: int) -> dict:
start_time = get_timescale().utc(year, 1, 1)
end_time = get_timescale().utc(year, 12, 31)
times, almanac_seasons = find_discrete(
start_time, end_time, almanac.seasons(get_skf_objects()))
seasons = {}
for time, almanac_season in zip(times, almanac_seasons):
if almanac_season == 0:
season = 'MARCH'
elif almanac_season == 1:
season = 'JUNE'
elif almanac_season == 2:
season = 'SEPTEMBER'
elif almanac_season == 3:
season = 'DECEMBER'
else:
raise AssertionError
seasons[season] = time.utc_iso()
return seasons
import matplotlib.pyplot as plt
fig, ax = plt.subplots()
ax.plot(t.J, gd - jd, '.') #, label='label', linestyle='--')
ax.axvline(325, color='blue')
#ax.plot(325, 0, '.') #, label='label', linestyle='--')
# ax.set(xlabel='time (s)', ylabel='voltage (mV)', title='Title')
# ax.set_aspect(aspect=1.0)
ax.grid()
# plt.legend()
ax.set_ylim(-10, 15)
fig.savefig('tmp.png')
exit()
eph = api.load('de422.bsp')
t, y = almanac.find_discrete(t0, t1, almanac.seasons(eph))
vernal = (y == 0)
t = t[vernal]
y = y[vernal]
#cal = t.ut1_calendar
cal = lambda: t.utc
gday = cal()[2]
for yi, ti in zip(y, t):
if 325 < ti.J <= 326:
print(yi, almanac.SEASON_EVENTS[yi], ti.utc_iso(' '))
ts.julian_calendar_cutoff = api.GREGORIAN_START
del t.utc
# Useful constants
SECS_IN_HOUR = 3600
HOURS_IN_DAY = 24
SECS_IN_DAY = SECS_IN_HOUR * HOURS_IN_DAY
UNIX_TS_OFFSET = datetime(1970, 1, 1).toordinal() * SECS_IN_DAY
DAYS_IN_YEAR = 365.2422
MOON_SYNODIC_PERIOD = 29.53
# Load Skyfield data
TIMESCALE = sf_api.load.timescale()
PLANETS = sf_api.load('de421.bsp')
SUN = PLANETS['sun']
MOON = PLANETS['moon']
EARTH = PLANETS['earth']
SEASONS = almanac.seasons(PLANETS)
# Genalized from skyfield/almanac.py
def PlanetObserver(planet, topos):
topos_at = (EARTH + topos).at
def _observe_at(t):
t._nutation_angles = iau2000b(t.tt)
return topos_at(t).observe(planet).apparent()
return _observe_at
# For computing sun/moon rise/set time
SUN_TOP_HORIZON = 0.26667
