Get distance between users using tomtom location api android

Question

I am developing an android app in which user can know distance between him and other users. I am using tomtom location api for this. I just want to know how to get the distance between current user and other user while i have latitude and longitude of both of them ?

Thanks in advance

Answer 1

If you already have coordinates of both users then you can calculate using below function. Answer is from SO thread here.

private double distance(double lat1, double lon1, double lat2, double lon2) {
    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;
    return (dist);
}

private double deg2rad(double deg) {
    return (deg * Math.PI / 180.0);
}

private double rad2deg(double rad) {
    return (rad * 180.0 / Math.PI);
}

Answer 2

I assume that you just need to calculate the great-circle distance between two points. There is math explenation hidden under this: http://www.movable-type.co.uk/scripts/latlong.html

Check TomTom class: com.tomtom.online.sdk.common.util.DistanceCalculator and methods:

• DistanceCalculator#greatCircleDistance(LatLng latLng, LatLng refLatLng)
• DistanceCalculator#calcDistInKilometers(LatLng destination, LatLng origin)

If you need to calculate precisely route distance, use routing sdk: https://developer.tomtom.com/maps-android-sdk/routing