Haversine Algorithm Implementation in Java

This is to calculate from two sets of points (Latitude, and Longitude) and distance based on the Earth's diameter/radius.

Here is the Haversine Formula followed by the java code. I've added Miles, KM, Meters, CM, Feet and Yards methods as well.

Haversine formula:	a = sin²(Δφ/2) + cos(φ1).cos(φ2).sin²(Δλ/2) c = 2.atan2(√a, √(1−a)) d = R.c
where	φ is latitude, λ is longitude, R is earth’s radius (mean radius = 6,371km)
	note that angles need to be in radians to pass to trig functions!

/**

 * This is the implementation Haversine Distance Algorithm between two places

 * @author amitapollo

 *  R = earth’s radius (mean radius = 6372.8km)

    Δlat = lat2 − lat1

    Δlong = long2 − long1

    a = sin²(Δlat/2) + cos(lat1).cos(lat2).sin²(Δlong/2)

    c = 2.atan2(√a, √(1−a))

    d = R.c * (distance converstion factor*)

 * 

 * * - km, mi, m, yds

 */

import java.lang.Math.*;

public class Haversine {

    /**

     * @param args

     * arg 1- latitude 1

     * arg 2 - longitude 1

     * arg 3 - latitude 2

     * arg 4 - longitude 2

     */

    public static final double RKilometers = 6372.8; // In kilometers

    public static final double RMiles = 10256.0; // In miles

    //returns kilometers between two sets of points (lat, lon)

    public static double haversineKilometers(double lat1, double lon1, double lat2, double lon2) {

        double dLat = Math.toRadians(lat2 - lat1);

        double dLon = Math.toRadians(lon2 - lon1);

        lat1 = Math.toRadians(lat1);

        lat2 = Math.toRadians(lat2);

 

        double a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.sin(dLon / 2) * Math.sin(dLon / 2) * Math.cos(lat1) * Math.cos(lat2);

        double c = 2 * Math.asin(Math.sqrt(a));

        return RKilometers * c;

    }

//returns meters between two sets of points (lat, lon)

    public static double haversineMeters(double lat1, double lon1, double lat2, double lon2) {

        double dLat = Math.toRadians(lat2 - lat1);

        double dLon = Math.toRadians(lon2 - lon1);

        lat1 = Math.toRadians(lat1);

        lat2 = Math.toRadians(lat2);

 

        double a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.sin(dLon / 2) * Math.sin(dLon / 2) * Math.cos(lat1) * Math.cos(lat2);

        double c = 2 * Math.asin(Math.sqrt(a));

        return RKilometers * c * 1000;

    }

    //returns centimeters between two sets of points (lat, lon)

    public static double haversineCentimeters(double lat1, double lon1, double lat2, double lon2) {

        double dLat = Math.toRadians(lat2 - lat1);

        double dLon = Math.toRadians(lon2 - lon1);

        lat1 = Math.toRadians(lat1);

        lat2 = Math.toRadians(lat2);

 

        double a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.sin(dLon / 2) * Math.sin(dLon / 2) * Math.cos(lat1) * Math.cos(lat2);

        double c = 2 * Math.asin(Math.sqrt(a));

        return RKilometers * c * 1000 * 100;

    }

    //returns miles between two sets of points (lat, lon)

    public static double haversineMiles(double lat1, double lon1, double lat2, double lon2) {

        double dLat = Math.toRadians(lat2 - lat1);

        double dLon = Math.toRadians(lon2 - lon1);

        lat1 = Math.toRadians(lat1);

        lat2 = Math.toRadians(lat2);

 

        double a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.sin(dLon / 2) * Math.sin(dLon / 2) * Math.cos(lat1) * Math.cos(lat2);

        double c = 2 * Math.asin(Math.sqrt(a));

        return RMiles * c;

    }

    //returns feet between two sets of points (lat, lon)

    public static double haversineFeet(double lat1, double lon1, double lat2, double lon2) {

        double dLat = Math.toRadians(lat2 - lat1);

        double dLon = Math.toRadians(lon2 - lon1);

        lat1 = Math.toRadians(lat1);

        lat2 = Math.toRadians(lat2);

 

        double a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.sin(dLon / 2) * Math.sin(dLon / 2) * Math.cos(lat1) * Math.cos(lat2);

        double c = 2 * Math.asin(Math.sqrt(a));

        return RMiles * c * 5280;

    }

    //returns inches between two sets of points (lat, lon)

    public static double haversineInches(double lat1, double lon1, double lat2, double lon2) {

        double dLat = Math.toRadians(lat2 - lat1);

        double dLon = Math.toRadians(lon2 - lon1);

        lat1 = Math.toRadians(lat1);

        lat2 = Math.toRadians(lat2);

 

        double a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.sin(dLon / 2) * Math.sin(dLon / 2) * Math.cos(lat1) * Math.cos(lat2);

        double c = 2 * Math.asin(Math.sqrt(a));

        return RMiles * c * 5280 * 12;

    }

    //returns yards between two sets of points (lat, lon)

    public static double haversineYards(double lat1, double lon1, double lat2, double lon2) {

        double dLat = Math.toRadians(lat2 - lat1);

        double dLon = Math.toRadians(lon2 - lon1);

        lat1 = Math.toRadians(lat1);

        lat2 = Math.toRadians(lat2);

 

        double a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.sin(dLon / 2) * Math.sin(dLon / 2) * Math.cos(lat1) * Math.cos(lat2);

        double c = 2 * Math.asin(Math.sqrt(a));

        return RMiles * c * 1760;

    }

    //CONVERTS value to Radians

    private static Double toRad(Double value) {

        return value * Math.PI / 180;

    }

}