distance

distanceLatLong.js

function distance(lat1, lon1, lat2, lon2) {
	var radlat1 = Math.PI * lat1/180
	var radlat2 = Math.PI * lat2/180
	var theta = lon1-lon2
	var radtheta = Math.PI * theta/180
	var dist = Math.sin(radlat1) * Math.sin(radlat2) + Math.cos(radlat1) * Math.cos(radlat2) * Math.cos(radtheta);
	dist = Math.acos(dist)
	dist = dist * 180/Math.PI
	dist = dist * 60 * 1.1515
	dist = dist * 1.609344
	return dist
}