rendered paste body#!/usr/bin/env python2## Copyright © 2010 Elizabeth Jennifer Myers. # All rights reserved.# # Redistribution and use in source and binary forms, with or without# modification, are permitted provided that the following conditions are met:# * Redistributions of source code must retain the above copyright# notice, this list of conditions and the following disclaimer.# * Redistributions in binary form must reproduce the above copyright# notice, this list of conditions and the following disclaimer in the# documentation and/or other materials provided with the distribution.# * Neither the name of the copyright holders nor the names of its# contributors may be used to endorse or promote products# derived from this software without specific prior written permission.## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE# ARE # DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.# =============================================================================# 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 math def 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