Gary, you got me thinking… I have been thinking about this average wind direction and it is actually pretty tricky to implement! The periodic nature of wind direction 0-359 degrees with a “reset” to 0 degrees is the kicker. Taking an average is more complicated than I thought! Assume we have thi…

[image] weather-display: as like Gary Funk showed but even better is too weight that vector with the windspeed It is weighted. Look closer at the formula.

[image] GaryFunk: var EW_Average = (EW_Vector / d.length) * -1; var NS_Average = (NS_Vector / d.length) * -1; just wondering where these two lines are good for, atan2(y,x) is almost the same as atan(y/x) so multiplying both with the same number is kind of pointless. isn’t it?

Those two lines get the average.

Okay. Try it both ways and see for yourself.

It doesn’t matter too much, I was just curious about how you calculated it. But those two lines are redundant. Atan((ya) /(xa)) is independent of the value of a ( unless a is zero). atan2 is just a fancy, better way of calculating this.

@peter Here is thread with the formula to calculation for average wind direction.

That formula looks correct but still I’m getting a very suspicious amount of northerly winds when the average windspeed in 1 minute is low but not zero. My sky is in powersave.

What if you rotated the SKY by 90 degrees or so to see if you still get “northerly winds?”

I would, but I’m already happy I managed to put up once. Going up twice for this test is a bit much, but it would help to diagnose of it was a software or hardware /firmware.

Calculate wind vector-direction

Developers

sunny September 9, 2018, 11:50pm 17

But atan2(10,20) is the same as atan2(1,2), so it’s not needed.

The good ole guys and coding skills from way way back ;-)

Topic		Replies	Views
Wind Direction when winds are calm should not be zero Feature Requests sky	47	6221	August 1, 2020
Wind direction in calm air should NOT be zero Feature Requests	0	1180	October 25, 2018
Wind direction in UDP messages Developers hub , tempest	6	566	June 25, 2020
Wind direction icon backward Tempest Owners tempest	44	4050	March 30, 2022
UDP API gives zero wind speed and angle Developers	6	779	December 1, 2020

Calculate wind vector-direction

Related topics