Creating a method using Haversine Formula, Android V2

Question

I'm not really good with mathematics but I need to calculate the distance of two different locations of the markers. Something like this:

public double CalculationByDistance(double initialLat, double initialLong, double finalLat, double finalLong){

return distance;
}

Or is there any alternative ways that I can calculate the distance of two markers, also I tried to google for answers.. but couldn't find any.

Reference: http://en.wikipedia.org/wiki/Haversine_formula

Comments are appreciated :) Thanks!!

Answer 1

Try this, much simpler than Haversine!

Location me   = new Location("");
Location dest = new Location("");

me.setLatitude(myLat);
me.setLongitude(myLong);

dest.setLatitude(destLat);
dest.setLongitude(destLong);

float dist = me.distanceTo(dest);

Answer 2

If you want to stick with Haversine, something like this:

public double CalculationByDistance(double initialLat, double initialLong,
                                double finalLat, double finalLong){
    int R = 6371; // km (Earth radius)
    double dLat = toRadians(finalLat-initialLat);
    double dLon = toRadians(finalLong-initialLong);
    initialLat = toRadians(initialLat);
    finalLat = toRadians(finalLat);

    double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
            Math.sin(dLon/2) * Math.sin(dLon/2) * Math.cos(initialLat) * Math.cos(finalLat); 
    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
    return R * c;
}

public double toRadians(double deg) {
  return deg * (Math.PI/180);
}

Also, you need to create a method toRadians() that convert values from degrees to radians, which is quite easy. Hope it helps!

Answer 3

From your wikipedia link, applying the formula directly you can do the following:

public double CalculationByDistance(double initialLat, double initialLong, double finalLat, double finalLong){
    /*PRE: All the input values are in radians!*/

    double latDiff = finalLat - initialLat;
    double longDiff = finalLong - initialLong;
    double earthRadius = 6371; //In Km if you want the distance in km

    double distance = 2*earthRadius*Math.asin(Math.sqrt(Math.pow(Math.sin(latDiff/2.0),2)+Math.cos(initialLat)*Math.cos(finalLat)*Math.pow(Math.sin(longDiff/2),2)));

    return distance;

}