Calculating distance between two points, using latitude longitude?

Question

Here's my try, it's just a snippet of my code:

final double RADIUS = 6371.01; double temp = Math.cos(Math.toRadians(latA))             * Math.cos(Math.toRadians(latB))             * Math.cos(Math.toRadians((latB) - (latA)))             + Math.sin(Math.toRadians(latA))             * Math.sin(Math.toRadians(latB));     return temp * RADIUS * Math.PI / 180; 

I am using this formulae to get the latitude and longitude:

x = Deg + (Min + Sec / 60) / 60) 

Answer 1

The Java code given by Dommer above gives slightly incorrect results but the small errors add up if you are processing say a GPS track. Here is an implementation of the Haversine method in Java which also takes into account height differences between two points.

/**  * Calculate distance between two points in latitude and longitude taking  * into account height difference. If you are not interested in height  * difference pass 0.0. Uses Haversine method as its base.  *   * lat1, lon1 Start point lat2, lon2 End point el1 Start altitude in meters  * el2 End altitude in meters  * @returns Distance in Meters  */ public static double distance(double lat1, double lat2, double lon1,         double lon2, double el1, double el2) {      final int R = 6371; // Radius of the earth      double latDistance = Math.toRadians(lat2 - lat1);     double lonDistance = Math.toRadians(lon2 - lon1);     double a = Math.sin(latDistance / 2) * Math.sin(latDistance / 2)             + Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2))             * Math.sin(lonDistance / 2) * Math.sin(lonDistance / 2);     double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));     double distance = R * c * 1000; // convert to meters      double height = el1 - el2;      distance = Math.pow(distance, 2) + Math.pow(height, 2);      return Math.sqrt(distance); } 

Answer 2

Here's a Java function that calculates the distance between two lat/long points, posted below, just in case it disappears again.

    private double distance(double lat1, double lon1, double lat2, double lon2, char unit) {       double theta = lon1 - lon2;       double dist = Math.sin(deg2rad(lat1)) * Math.sin(deg2rad(lat2)) + Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * Math.cos(deg2rad(theta));       dist = Math.acos(dist);       dist = rad2deg(dist);       dist = dist * 60 * 1.1515;       if (unit == 'K') {         dist = dist * 1.609344;       } else if (unit == 'N') {         dist = dist * 0.8684;         }       return (dist);     }          /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/     /*::  This function converts decimal degrees to radians             :*/     /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/     private double deg2rad(double deg) {       return (deg * Math.PI / 180.0);     }          /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/     /*::  This function converts radians to decimal degrees             :*/     /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/     private double rad2deg(double rad) {       return (rad * 180.0 / Math.PI);     }          System.out.println(distance(32.9697, -96.80322, 29.46786, -98.53506, 'M') + " Miles\n");     System.out.println(distance(32.9697, -96.80322, 29.46786, -98.53506, 'K') + " Kilometers\n");     System.out.println(distance(32.9697, -96.80322, 29.46786, -98.53506, 'N') + " Nautical Miles\n");