def distance(lat1, lon1, lat2, lon2, R=3959):
# http://andrew.hedges.name/experiments/haversine/
dlon = radians(lon2 - lon1)
dlat = radians(lat2 - lat1)
a = sin(dlat / 2.0) ** 2 + cos(lat1) * cos(lat2) * sin(dlon / 2.0) ** 2
return R * 2 * atan2(sqrt(a), sqrt(1 - a))
def distance(lat1, lon1, lat2, lon2, R=3959):
# http://andrew.hedges.name/experiments/haversine/
dlon = radians(lon2 - lon1)
dlat = radians(lat2 - lat1)
a = sin(dlat / 2.0) ** 2 + cos(lat1) * cos(lat2) * sin(dlon / 2.0) ** 2
return R * 2 * atan2(sqrt(a), sqrt(1 - a))
