function distance(
{ latitude: latitude0, longitude: longitude0 },
{ latitude: latitude1, longitude: longitude1 }
) {
var R = 6371;
var dLat = deg2rad((latitude1 - latitude0) / 1e7);
var dLon = deg2rad((longitude1 - longitude0) / 1e7);
var a =
Math.sin(dLat / 2) * Math.sin(dLat / 2) +
Math.cos(deg2rad(latitude0 / 1e7)) *
Math.cos(deg2rad(latitude1 / 1e7)) *
Math.sin(dLon / 2) *
Math.sin(dLon / 2);
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
var d = R * c;
return d;
}