Wind direction indicator

I'm writing a "wind direction" addition to my application and looking at the Position.Info.bearing. It says "The true north referenced heading in radians". Does that mean that 0 is north and "heading 359" is -pi/180 and "heading 1" is pi/180? The simulator is outputting something in the range [-2, 2] so I'm having trouble guessing valid values what to expect. Apparently is not the "natural" radians in the range[0, 2*pi] starting from "east", going counterclockwise?

The Weather.currentConditions.windBearing is apparently in "degrees clockwise"-format so I'm trying to combine the rider heading and wind bearing to indicate where the wind is coming from...

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+1 Travis.ConnectIQ over 4 years ago

0 is north. -PI/2 radians (90deg CCW) is west, and +PI/2 radians (90deg CW) is east.

0 DaveBrillhart over 3 years ago in reply to Travis.ConnectIQ

To to make currentHeading consistent with Wind Direction, we have to apply Math.toDegrees() and add 360 if the result is a negative number. Wind Direction returns 0-359 degrees I believe.

0 Alan.raceQs over 3 years ago in reply to DaveBrillhart

Wouldn't it be nice if the documentation included a statement about the value range that the function returned, instead of us having to expend time and energy to discover it ourselves?

0 xuxumatu over 2 years ago in reply to Alan.raceQs

it's a problem not to have same units as heading because you can not make a real wind compass using math operations, in fact I don't know haw to do it,

+1 DaveBrillhart over 2 years ago in reply to xuxumatu

Easy! Well, easy is relative. But really... it is trivial once you play around a little and reconcile the two values. I posted over a year ago here how to do it... here are excerpts from my code: relWind is the relative direction of the wind in relation to your actual heading. I do more with this like draw an arrow and color code it RED, GREEN or GRAY depending on head, tail or cross wind.

heading = myInfo.currentHeading < 0 ? 360.0 + Math.toDegrees(myInfo.currentHeading) : Math.toDegrees(myInfo.currentHeading);

relWind = windBearing - heading; relWind = relWind < 0 ? relWind + 360.0 : relWind;

0 Vallecino over 2 years ago in reply to xuxumatu

I made a compass and a wind direction/force indicator. had to use:

windheadRad = Math.toRadians((450-cc.windBearing)%360);

and to show in relation to the compass

windheadrelative = windheadRad + compass + Math.PI/2 ; // where compass = info.currentHeading + Math.PI/2

0 xuxumatu over 2 years ago in reply to Vallecino

that was genius!!

0 xuxumatu over 2 years ago in reply to xuxumatu

ok one more question how do I work all in degrees?

0 DaveBrillhart over 2 years ago in reply to xuxumatu

Did you see my reply? I work in degrees. Here is my data field, showing in this case the wind is almost entirely a tailwind (Green arrow; a headwind is RED, crosswind is GRAY) in relation to my current heading. The wind is coming FROM the WNW at 1.1mph. I got that update 1 min ago. Cheers

0 xuxumatu over 2 years ago in reply to DaveBrillhart

this one, Is it correct this way?

heading = myInfo.currentHeading < 0 ? 360.0 + Math.toDegrees(myInfo.currentHeading) : Math.toDegrees(myInfo.currentHeading);

relWind = windBearing - heading;

relWind = relWind < 0 ? relWind + 360.0 : relWind;