def find_closest(cls,
generic_asset_type_name: str,
sensor_name: str,
n: int = 1,
**kwargs) -> Union["Sensor", List["Sensor"], None]:
"""Returns the closest n sensors within a given asset type (as a list if n > 1).
Parses latitude and longitude values stated in kwargs.
Can be called with an object that has latitude and longitude properties, for example:
sensor = Sensor.find_closest("weather_station", "wind speed", object=generic_asset)
Can also be called with latitude and longitude parameters, for example:
sensor = Sensor.find_closest("weather_station", "temperature", latitude=32, longitude=54)
sensor = Sensor.find_closest("weather_station", "temperature", lat=32, lng=54)
Finally, pass in an account_id parameter if you want to query an account other than your own. This only works for admins. Public assets are always queried.
"""
latitude, longitude = parse_lat_lng(kwargs)
account_id_filter = kwargs[
"account_id"] if "account_id" in kwargs else None
query = query_sensors_by_proximity(
latitude=latitude,
longitude=longitude,
generic_asset_type_name=generic_asset_type_name,
sensor_name=sensor_name,
account_id=account_id_filter,
)
if n == 1:
return query.first()
else:
return query.limit(n).all()
def find_closest_weather_sensor(
sensor_type: str,
n: int = 1,
**kwargs) -> Union[WeatherSensor, List[WeatherSensor], None]:
"""Returns the closest n weather sensors of a given type (as a list if n > 1).
Parses latitude and longitude values stated in kwargs.
Can be called with an object that has latitude and longitude properties, for example:
sensor = find_closest_weather_sensor("wind_speed", object=asset)
Can also be called with latitude and longitude parameters, for example:
sensor = find_closest_weather_sensor("temperature", latitude=32, longitude=54)
sensor = find_closest_weather_sensor("temperature", lat=32, lng=54)
"""
latitude, longitude = parse_lat_lng(kwargs)
sensors = WeatherSensor.query.filter(
WeatherSensor.weather_sensor_type_name == sensor_type).order_by(
WeatherSensor.great_circle_distance(lat=latitude,
lng=longitude).asc())
if n == 1:
return sensors.first()
else:
return sensors.limit(n).all()
def great_circle_distance(self, **kwargs):
"""Query great circle distance (in km).
Can be called with an object that has latitude and longitude properties, for example:
great_circle_distance(object=asset)
Can also be called with latitude and longitude parameters, for example:
great_circle_distance(latitude=32, longitude=54)
great_circle_distance(lat=32, lng=54)
"""
other_location = geo_utils.parse_lat_lng(kwargs)
if None in other_location:
return None
return geo_utils.earth_distance(self.location, other_location)
def great_circle_distance(self, **kwargs):
"""Query great circle distance (unclear if in km or in miles).
Can be called with an object that has latitude and longitude properties, for example:
great_circle_distance(object=asset)
Can also be called with latitude and longitude parameters, for example:
great_circle_distance(latitude=32, longitude=54)
great_circle_distance(lat=32, lng=54)
"""
other_latitude, other_longitude = parse_lat_lng(kwargs)
if other_latitude is None or other_longitude is None:
return None
return func.earth_distance(
func.ll_to_earth(self.latitude, self.longitude),
func.ll_to_earth(other_latitude, other_longitude),
)
def great_circle_distance(self, **kwargs):
"""Query great circle distance (in km).
Can be called with an object that has latitude and longitude properties, for example:
great_circle_distance(object=asset)
Can also be called with latitude and longitude parameters, for example:
great_circle_distance(latitude=32, longitude=54)
great_circle_distance(lat=32, lng=54)
"""
r = 6371 # Radius of Earth in kilometers
other_latitude, other_longitude = parse_lat_lng(kwargs)
if other_latitude is None or other_longitude is None:
return None
other_cos_rad_lat = math.cos(math.radians(other_latitude))
other_sin_rad_lat = math.sin(math.radians(other_latitude))
other_rad_lng = math.radians(other_longitude)
return (math.acos(self.cos_rad_lat * other_cos_rad_lat *
math.cos(self.rad_lng - other_rad_lng) +
self.sin_rad_lat * other_sin_rad_lat) * r)