I am trying to convert the code snippet given in this http://www.movable-type.co.uk/scripts/latlong.html into java. But I am not getting same result as that of site. Here is my code to find the midpoint between two points where their latitudes and longitudes are given
midPoint(12.870672,77.658964,12.974831,77.60935); public static void midPoint(double lat1,double lon1,double lat2,double lon2) { double dLon = Math.toRadians(lon2-lon1); double Bx = Math.cos(lat2) * Math.cos(dLon); double By = Math.cos(lat2) * Math.sin(dLon); double lat3 = Math.atan2(Math.sin(lat1)+Math.sin(lat2),Math.sqrt( (Math.cos(lat1)+Bx)*(Math.cos(lat1)+Bx) + By*By) ); double lon3 = lon1 + Math.atan2(By, Math.cos(lat1) + Bx); System.out.print(lat3 +" " + lon3 ); }
I am not sure whethe dLon is correct or not. So please help me guys to figure it out. P.S.I need to find the latitude and longitude of the midpoint
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Answer
You need to convert to radians. Change it to the following:
public static void midPoint(double lat1,double lon1,double lat2,double lon2){ double dLon = Math.toRadians(lon2 - lon1); //convert to radians lat1 = Math.toRadians(lat1); lat2 = Math.toRadians(lat2); lon1 = Math.toRadians(lon1); double Bx = Math.cos(lat2) * Math.cos(dLon); double By = Math.cos(lat2) * Math.sin(dLon); double lat3 = Math.atan2(Math.sin(lat1) + Math.sin(lat2), Math.sqrt((Math.cos(lat1) + Bx) * (Math.cos(lat1) + Bx) + By * By)); double lon3 = lon1 + Math.atan2(By, Math.cos(lat1) + Bx); //print out in degrees System.out.println(Math.toDegrees(lat3) + " " + Math.toDegrees(lon3)); }