The 359-0 problem can solved easy by changing from polar coordinate system (velocity+direction) to cartesian coordinate system: Wind_X = velocity * cos(direction * PI / 180) Wind_Y = velocity * sin(direction * PI / 180)
The normal AVERAGE aggregate function can applied to Wind_X and Wind_Y. The back transformation is: velocity = Sqrt(Wind_X*Wind_X + Wind_Y*Wind_Y) direction = Atan2(Wind_Y, Wind_Y) * 180 / PI I read in the rrd documentation, that calculated data source are possible. So a solution would be: Define 2 data source Wind_X, Wind_Y. The update program has calculate Wind_X, Wind_Y from velocity+direction. Can I define velocity and direction as calculated data source with the formulas? velocity = Sqrt(Wind_X*Wind_X + Wind_Y*Wind_Y) direction = Atan2(Wind_Y, Wind_Y) * 180 / PI -- View this message in context: http://rrd-mailinglists.937164.n2.nabble.com/How-store-wind-vector-data-tp7581910p7581914.html Sent from the RRDtool Users Mailinglist mailing list archive at Nabble.com. _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
