rendered paste body#!/usr/bin/env/python# Copyright © 2010 Elizabeth Jennifer Myers. All rights reserved.## This program is free software. It comes without any warranty, to# the extent permitted by applicable law. You can redistribute it# and/or modify it under the terms of the Do What The Fuck You Want# To Public License, Version 2, as published by Sam Hocevar. See# http://sam.zoy.org/wtfpl/COPYING for more details# Based on the formula for great-circle distance# (http://en.wikipedia.org/wiki/Great-circle_distance)## Note that this is not 100% accurate as the earth isn't a "true" sphere, but# for our purposes it's plenty (guaranteed within 0.5%).import mathdef GeoDistance(lat1, lon1, lat2, lon2): """ Calculate the distance between two latitude and longitude pairs on earth. Note that negative numbers denote west and south, and positive numbers denote east and north. """ phi1 = math.radians(90.0 - lat1) phi2 = math.radians(90.0 - lat2) theta1 = math.radians(lon1) theta2 = math.radians(lon2) arc = math.acos(math.sin(phi1) * math.sin(phi2) * math.cos(theta1 - theta2) + math.cos(phi1) * math.cos(phi2)) # 6335.439 is the average radius of the earth in km. return arc * 6335.439