Location/Haversine

Python
from stackoverflow.com

from math import * def haversine(lon1, lat1, lon2, lat2): """ Calculate the great circle distance between two points on the earth (specified in decimal degrees) """ lon1, lat1, lon2, lat2 = map(radians, [lon1, lat1, lon2, lat2]) dlon = lon2 - lon1 dlat = lat2 - lat1 a = sin(dlat/2)**2 + cos(lat1) * cos(lat2) * sin(dlon/2)**2 c = 2 * atan2(sqrt(a), sqrt(1-a)) km = 6367 * c return km
 * 1) convert decimal degrees to radians
 * 1) haversine formula