> -----Original Message----- > From: Tris > Sent: Wednesday, August 01, 2007 7:28 AM > Hi all... > I've been asked to calculate how far postcode x is from post code y... > No worries.. as I found this great page... > http://www.easypeasy.com/guides/article.php?article=64 > > Taking his DB and sample maths, I've created this page: > http://www.tlc-rewards.com/_postcodeChecker/check.php?pointOne =W1U&pointTwo=e1 > to test... > > But I'm feeling it's not accurate... > So I'm hoping for a little testing? ;-p Great Circle calculations are very well established and are more accurate than the simple straight line calculation provided with that post code database. The database you mentioned provides lat and lon for each post code, so you can use any of the many online tools, such as the following, to confirm your calculation: http://www.movable-type.co.uk/scripts/latlong.html Or, if you just want the pseudo-code: http://www.cs.dartmouth.edu/~akapadia/java/latlon/snippet.html Joshua <><><><><><><><><><> Joshua L. Olson WAE Technologies, Inc. http://www.waetech.com/ Phone: 706.210.0168 Fax: 413.812.4864 Private Enterprise Number: 28752 Monitor bandwidth usage on IIS6 in real-time: http://www.waetech.com/services/iisbm/