NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Location Center of Responses thus Far
From: Glendon
Date: 2001 Jul 23, 7:04 PM
From: Glendon
Date: 2001 Jul 23, 7:04 PM
Its an optimisation problem isn't it? Let x be the unknown location centre Let D(i) be the great circle distance between the i th member and x Then we want to choose x such as to: minimise{sum of [ D(i); i=1-n]} or, minimise{sumof[ square of D(i): i=1-n]} subject to x lying between lat and lon of 0-360 hmmm, shipping or airline companies must have tackled this one?? Lee Martin ----- Original Message ----- From "Dan Allen"To: Sent: Tuesday, July 24, 2001 7:23 AM Subject: Location Center of Responses thus Far > The following people have replied so far to my request for location: > > NAME LAT LON > ================================ > Allen Dan 47.482 121.798 > Arrouye Yves 37.892 122.997 > Emerson Rick 40.245 75.252 > Gilbert Greg -35.167 -138.75 > Hogan Dan 33.147 117.958 > Huxtable* George 51.6 1.28 > Murdoch* Bill 36.548 82.562 > Ouvry Philip 42.43 -3.15 > Sher* Russell -33.933 -18.367 > Simmonds John -37.353 -143.635 > Smith Peter 42.217 71.283 > Talge Gordon 34.052 117.253 > Taylor* Chuck 47.9 122.3 > Tripp Steven 37.5 -140 > > * = Position approximated by looking up city in Encarta World Atlas > (North and West are positive, South and East are negative) > > Using these 14 data points, the average latitude is 24.6 North, > and the average longitude is 27.7 West, a spot 487 nautical miles > north of Mindelo, Cape Verde islands in the central Atlantic ocean. > This is quite a distance from the nearest restaurant. > > The nearest spot on a continent is Nouakchott, Mauritania, 761 nmi SE. > It is 1177 nautical miles NE to Casablanca in Morocco. > > Hmmmm... > > Daniel K. Allen > danallen@nwlink.com > http://www.nwlink.com/~danallen/ > Measure | Analyze | Communicate >