Source code for

import logging
from datetime import datetime, timedelta
from django.db import models
import numpy as np
import pytz

from .station import WeatherStation

log = logging.getLogger(__name__)

[docs]class Average(WeatherStation): """The Average weather station requests all values from all other weather stations and calculates 5-minutes averages for all sensor types. This station gets configured by the *initweather* script and is running on a crontab every 5 minutes. """
[docs] def create_sensors(self): """Entry point for creating sensors for this station. No sensors created here, that all happens on-the-fly in update().""" pass
[docs] def update(self): """Entry point for updating sensor values for this station. This method loops all sensor types and fetches all related sensors from all stations and calculates 5-minutes averages, which it stores in sensors of the same type. """ from import SensorType, Sensor, Value'Updating averages...') # get now and since now = datetime.utcnow().astimezone(pytz.UTC) since = now - timedelta(minutes=5, seconds=30) # loop all sensor types for sensor_type in SensorType.objects.filter(average=True): values = [] # skip those that we don't want to calculate averages for if not sensor_type.average: continue # loop all sensors of that type for sensor in Sensor.objects.filter(type=sensor_type, average=True, station__active=True): # get average value for this sensor for last 5:30 minutes value = Value.objects.filter(sensor=sensor, time__gte=since).aggregate(models.Avg('value')) # valid? if value is not None and value['value__avg'] is not None: # add it values.append(value['value__avg']) # calculate average of all sensors avg = np.nanmean(values) if values else None # and store it sensor = self._add_sensor(sensor_type.code) Value.objects.get_or_create(sensor=sensor, time=now, value=avg)
__all__ = ['Average']