Nodejs Distance Calculate calculateDistance(lat2, lon2)

Method Source Code

/* calculateDistance() function adapted from 
   * latitude/longitude spherical geodesy formulae & scripts
   * (c) Chris Veness 2002-2010//from w w w .  j av  a2  s .c o  m
   * www.movable-type.co.uk/scripts/latlong.html */

function calculateDistance(lat2, lon2) {
  var R = 3959; // radius of Earth in miles
  var lat1 = 47.3193057;
  var lon1 = -93.2895824;
  var dLat = (lat2 - lat1).toRad();
  var dLon = (lon2 - lon1).toRad(); 
  var a = Math.sin(dLat / 2) * Math.sin(dLat / 2) +
          Math.cos(lat1.toRad()) * Math.cos(lat2.toRad()) * 
          Math.sin(dLon / 2) * Math.sin(dLon / 2); 
  var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a)); 
  var d = Math.round(R * c);
  return d;
}

Related

1. distance(lat1, lon1, lat2, lon2)

   exports.distance = function(lat1, lon1, lat2, lon2) {
     var radlat1 = Math.PI * lat1/180;
     var radlat2 = Math.PI * lat2/180;
     var radlon1 = Math.PI * lon1/180;
     var radlon2 = Math.PI * lon2/180;
     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);
   ...
   

2. distance(lat1, lon1, lat2, lon2)

   function distance(lat1, lon1, lat2, lon2) {
     var R = 6371;
     var a = 0.5 - Math.cos((lat2 - lat1) * Math.PI / 180)/2 + 
        Math.cos(lat1 * Math.PI / 180) * Math.cos(lat2 * Math.PI / 180) * 
        (1 - Math.cos((lon2 - lon1) * Math.PI / 180))/2;
     var m = R * 2 * Math.asin(Math.sqrt(a))*1000;
     return Math.floor(m);
   

3. distance(lat1,lon1,lat2,lon2)

   function distance(lat1,lon1,lat2,lon2) {
     var R = 6371; 
     var dLat = deg2rad(lat2-lat1);  
     var dLon = deg2rad(lon2-lon1);
     var a =
       Math.sin(dLat/2) * Math.sin(dLat/2) +
       Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) *
       Math.sin(dLon/2) * Math.sin(dLon/2)
       ;
   ...
   

4. distance(p1, p2)

   function Point(x, y) {
       this.x = x;
       this.y = y;
   function randomPoint() {
       var randomx = randomNumber(WIDTH);
       var randomy = randomNumber(HEIGHT);
       var randomPoint = new Point(randomx, randomy);
       return randomPoint;
   ...