public static double CalculateDistance(Coordinates point1, Coordinates point2)
{
double lat1 = point1.Latitude;
double lon1 = point1.Longitude;
double lat2 = point2.Latitude;
double lon2 = point2.Longitude;
double R = 6371;
double dLat = (lat2 - lat1).ToRad();
double dLon = (lon2 - lon1).ToRad();
double firstLat = lat1.ToRad();
double secondLat = lat2.ToRad();
double a = Math.Sin(dLat/2)*Math.Sin(dLat/2) +
Math.Sin(dLon/2)*Math.Sin(dLon/2)*Math.Cos(firstLat)*Math.Cos(secondLat);
double c = 2*Math.Atan2(Math.Sqrt(a), Math.Sqrt(1 - a));
return R*c;
}
public IEnumerable<HelpRequest> GetRequestsNearPoint(Coordinates point, double maxDistance)
{
return dbContext.HelpRequests.ToList()
.Where(r => r.Coordinates != null &&
DistanceCalculator.CalculateDistance(point, r.Coordinates) <= maxDistance).ToList();
}
