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From: achut@callan.UUCP (Achut Reddy)
Newsgroups: net.puzzle
Subject: Re: average wind direction puzzle
Message-ID: <196@callan.UUCP>
Date: Wed, 25-Jul-84 03:16:43 EDT
Article-I.D.: callan.196
Posted: Wed Jul 25 03:16:43 1984
Date-Received: Sat, 21-Jul-84 03:08:34 EDT
References: <146@ios.UUCP>
Organization: Callan Data Systems, Westlake Village, CA
Lines: 15

From: richa@ios.UUCP (Rich Altmaier)
Organization: Integrated Office Systems, Cupertino CA

Consider measuring wind direction with an instrument that gives compass
angles (e.g. 0..359 degrees).  Suppose you wish to take several readings
and give an average wind direction.  What's a good algorithm for this?

If you take a set of readings and just numerically average the values,
you may find you never get results near 0/360 and you get lobes near
180 (which won't be correct).  Consider a reading set such as
355, 359, 3, 1.  Average wind direction is about 359 degrees.

	R. Altmaier
	{qubix, oliveb, decwrl}!ios!richa