OpenSprinkler › Forums › OpenSprinkler Unified Firmware › Weather Adjustment Behavior Weather Underground compared to OWM › Reply To: Weather Adjustment Behavior Weather Underground compared to OWM
Hi admittedly I am not sure if I searched at the right position. I tried to find the position where the weather data is downloaded.
The latest fix is called “Average out the incoming data from OpenWeatherMaps” and was done 4 month ago.
Here I find the following api call to owm:
forecastUrl = “http://api.openweathermap.org/data/2.5/forecast?appid=” + OWM_API_KEY + “&units=imperial&lat=” + location[ 0 ] + “&lon=” + location[ 1 ];
which is a forecast the next days (3 hourly up to 5 days).
THen the temperatures, humidity, rainfall etc. are averaged across the first 10 entries (which essentially is 30 hours). A potential problem here is that if a data point is missing, hence as the algorithm sums over values if NaN is added then at least the denominator of 10 is false, but not sure if that does not lead to an NaN overall.
There is also a comment by tekshed that this might be a problem.
Finally I am also a bit puzzled that the forecast data is used here. Zimmerman relies on the previous data not the future data, but not sure if this call is also used by the Zimmerman algorithm.
So potentially here could be the problem (wrong averaging if data is missing (NaN)) and also using forecast instead of historical data.
Anyone out there with a better understanding that might be able to have a look at it.
github link to the commit