latitude-longitude

I have this code, written using this: source1 and this: source 2 public static double CalculatePolygonArea(IList<GpsLocation> coordinates) { double area = 0; if (coordinates.Count > 2) { for (var i = 0; i < coordinates.Count-1; i++) { GpsLocation p1, p2; p1 = coordinates[i]; p2 = coordinates[i + 1]; area += ToRad(p2.Longitude - p1.Longitude) * (2 + Math.Sin(ToRad(p1.Latitude)) + Math.Sin(ToRad(p2.Latitude))); area = area * R * R / 2; } } return Math.Abs(area); } Here is my test code: [Fact] public void GpsPolygonAreaTest() { var poly = new List<GpsLocation>(); var p1 = new GpsLocation(0, 0);

i dont understand why locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER); return the location null. I gave all permission but its reutning null . if (isGPSEnabled) { if (location == null) { locationManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this); Log.d("GPS", "GPS Enabled"); if (locationManager != null) { location = locationManager .getLastKnownLocation(LocationManager.GPS_PROVIDER); if (location != null) { latitude = location.getLatitude(); longitude = location.getLongitude(); } } } } I had this exact

I have a mysql Database and 2 tables let's say clients and schools. Now each table has columns latitude and longitude. And I need do make a SELECT for example from second table where schools are in a given radius of one record from first table. Calculations should be made based on latitude and longitude. PS: I am using PHP. You can calculate a distance using a Spherical law of cosines : SELECT DEGREES(ACOS(SIN(RADIANS(clients.latitude)) * SIN(RADIANS(schools.latitude)) + COS(RADIANS(clients.latitude)) * COS(RADIANS(schools.latitude)) * COS(RADIANS(clients.longitude – schools.longitude)))) * 60

How can I convert this: 26.72773551940918 Into something like this: 22°12'42"N The trick here is that the coordinates are, actually Latitude and Longitude, I just need to format them correctly. You can find functions to do that here <?php function DMStoDEC($deg,$min,$sec) { // Converts DMS ( Degrees / minutes / seconds ) // to decimal format longitude / latitude return $deg+((($min*60)+($sec))/3600); } function DECtoDMS($dec) { // Converts decimal longitude / latitude to DMS // ( Degrees / minutes / seconds ) // This is the piece of code which may appear to // be inefficient, but to avoid