__all__ = ("Almanac",)
import datetime
import os
import numpy as np
from scipy.interpolate import interp1d
from rubin_scheduler.data import get_data_dir
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class Almanac:
"""Class to load and return pre-computed information about the
LSST site."""
def __init__(self, mjd_start=None, kind="quadratic"):
# Load up the sunrise/sunset times
data_dir = os.path.join(get_data_dir(), "site_models")
temp = np.load(os.path.join(data_dir, "sunsets.npz"))
self.sunsets = temp["almanac"].copy()
temp.close()
if mjd_start is not None:
loc = np.searchsorted(self.sunsets["sunset"], mjd_start)
# Set the start MJD to be night 1.
self.sunsets["night"] -= self.sunsets["night"][loc - 1]
# Load the sun and moon positions
temp = np.load(os.path.join(data_dir, "sun_moon.npz"))
self.sun_moon = temp["sun_moon_info"].copy()
temp.close()
self.interpolators = {
"sun_alt": interp1d(self.sun_moon["mjd"], self.sun_moon["sun_alt"], kind=kind),
"sun_az_x": interp1d(self.sun_moon["mjd"], np.cos(self.sun_moon["sun_az"]), kind=kind),
"sun_az_y": interp1d(self.sun_moon["mjd"], np.sin(self.sun_moon["sun_az"]), kind=kind),
"sun_RA_x": interp1d(self.sun_moon["mjd"], np.cos(self.sun_moon["sun_RA"]), kind=kind),
"sun_RA_y": interp1d(self.sun_moon["mjd"], np.sin(self.sun_moon["sun_RA"]), kind=kind),
"sun_dec": interp1d(self.sun_moon["mjd"], self.sun_moon["sun_dec"], kind=kind),
"moon_alt": interp1d(self.sun_moon["mjd"], self.sun_moon["moon_alt"], kind=kind),
"moon_az_x": interp1d(self.sun_moon["mjd"], np.cos(self.sun_moon["moon_az"]), kind=kind),
"moon_az_y": interp1d(self.sun_moon["mjd"], np.sin(self.sun_moon["moon_az"]), kind=kind),
"moon_RA_x": interp1d(self.sun_moon["mjd"], np.cos(self.sun_moon["moon_RA"]), kind=kind),
"moon_RA_y": interp1d(self.sun_moon["mjd"], np.sin(self.sun_moon["moon_RA"]), kind=kind),
"moon_dec": interp1d(self.sun_moon["mjd"], self.sun_moon["moon_dec"], kind=kind),
"moon_phase": interp1d(self.sun_moon["mjd"], self.sun_moon["moon_phase"], kind=kind),
}
temp = np.load(os.path.join(data_dir, "planet_locations.npz"))
self.planet_loc = temp["planet_loc"].copy()
temp.close()
self.planet_names = ["venus", "mars", "jupiter", "saturn"]
self.planet_interpolators = {}
for pn in self.planet_names:
self.planet_interpolators[pn + "_RA_x"] = interp1d(
self.planet_loc["mjd"], np.cos(self.planet_loc[pn + "_RA"]), kind=kind
)
self.planet_interpolators[pn + "_RA_y"] = interp1d(
self.planet_loc["mjd"], np.sin(self.planet_loc[pn + "_RA"]), kind=kind
)
self.planet_interpolators[pn + "_dec"] = interp1d(
self.planet_loc["mjd"], self.planet_loc[pn + "_dec"], kind=kind
)
def get_planet_positions(self, mjd):
result = {}
for pn in self.planet_names:
result[pn + "_dec"] = self.planet_interpolators[pn + "_dec"](mjd)
temp_result = np.array(
[
np.arctan2(
self.planet_interpolators[pn + "_RA_y"](mjd),
self.planet_interpolators[pn + "_RA_x"](mjd),
)
]
).ravel()
negative_angles = np.where(temp_result < 0.0)[0]
temp_result[negative_angles] = 2.0 * np.pi + temp_result[negative_angles]
result[pn + "_RA"] = temp_result
return result
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def get_sunset_info(self, mjd=None, evening_date=None, longitude=None):
"""Returns a numpy array with mjds for various events
(sunset, moonrise, sun at -12 degrees alt, etc.).
Parameters
----------
mjd : `float`
A UTC MJD that occurs during the desired night.
Defaults to None.
evening_date : `str` or `datetime.date`
The local date of the evening of the night whose index is
desired, in ISO8601 format (YYYY-MM-DD). Defaults to None.
longitude : `float` or `astropy.coordinates.angles.core.Angle`
If a float, then the value is interpreted as being in radians.
Defaults to None.
Returns
-------
sunset_info : `numpy.void`
A numpy object with dtype([
('night', '<i8'),
('sunset', '<f8'),
('sun_n12_setting', '<f8'),
('sun_n18_setting', '<f8'),
('sun_n18_rising', '<f8'),
('sun_n12_rising', '<f8'),
('sunrise', '<f8'),
('moonrise', '<f8'),
('moonset', '<f8')
])
"""
if mjd is not None and evening_date is not None:
raise ValueError("At most one of mjd and evening_date can be set")
# Default to now
if mjd is None and evening_date is None:
mjd = 40587 + datetime.datetime.now().timestamp() / (24 * 60 * 60)
if mjd is not None:
indx = np.searchsorted(self.sunsets["sunset"], mjd, side="right") - 1
elif evening_date is not None:
if longitude is None:
raise ValueError("If evening_date is set, longitude is needed as well")
indx = self.index_for_local_evening(evening_date, longitude)
return self.sunsets[indx]
def mjd_indx(self, mjd):
indx = np.searchsorted(self.sunsets["sunset"], mjd, side="right") - 1
return indx
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def index_for_local_evening(self, evening_date, longitude):
"""The index of the night with sunset at a given local date.
Parameters
----------
evening_date : `str` or `datetime.date`
The local date of the evening of the night whose index i
desired, in ISO8601 format (YYYY-MM-DD).
longitude : `float` or `astropy.coordinates.angles.core.Angle`
If a float, then the value is interpreted as being in radians.
Returns
-------
night_index : `int`
The index of the requested night.
"""
try:
longitude = longitude.radian
except AttributeError:
pass
if isinstance(evening_date, str):
evening_date = datetime.date.fromisoformat(evening_date)
evening_datetime = datetime.datetime(evening_date.year, evening_date.month, evening_date.day)
evening_mjd = np.floor(evening_datetime.timestamp() / (24 * 60 * 60) + 40587)
# Depending on the time of year, the UTC date rollover might not
# always be on the same side of local sunset. Shift by the
# longitude to make sure the rollover is always near midnight,
# far from sunset.
matching_nights = np.argwhere(
np.floor(self.sunsets["sunset"] + longitude / (2 * np.pi)) == evening_mjd
)
if len(matching_nights) < 1:
raise ValueError(f"Requested night {evening_date} outside of almanac date range")
night_index = matching_nights.item()
return night_index
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def get_sun_moon_positions(self, mjd):
"""
All angles in Radians. moonPhase between 0 and 100.
"""
simple_calls = ["sun_alt", "sun_dec", "moon_alt", "moon_dec", "moon_phase"]
result = {}
for key in simple_calls:
result[key] = self.interpolators[key](mjd)
longitude_calls = ["sun_az", "moon_az", "sun_RA", "moon_RA"]
for key in longitude_calls:
# Need to wrap in case sent a scalar
temp_result = np.array(
[
np.arctan2(
self.interpolators[key + "_y"](mjd),
self.interpolators[key + "_x"](mjd),
)
]
).ravel()
negative_angles = np.where(temp_result < 0.0)[0]
temp_result[negative_angles] = 2.0 * np.pi + temp_result[negative_angles]
result[key] = temp_result
return result
