public static List <Customer> LivingWithin100Km(ICustomerDB potentialCustomers)
{
LatLong DublinOffice = new LatLong(53.3393, -6.2576841);
List <Customer> customers = new List <Customer>();
foreach (Customer customer in potentialCustomers.Customers)
{
if (Earth.DistanceBetween(DublinOffice, customer.GpsCoord) <= 100.00)
{
customers.Add(customer);
}
}
customers.Sort((left, right) => left.Id.CompareTo(right.Id));
return(customers);
}
/// <summary>
/// Given two positions (latitude/longitude) on Earth,
/// calculate the distance in kilometres between them.
/// </summary>
public static double DistanceBetween(LatLong pointA, LatLong pointB)
{
double avgRadiusOfEarth = 6371.392896; //Radius of the earth differ, I'm taking the average.
//Haversine formula
//distance = R * 2 * aTan2 ( square root of A, square root of 1 - A )
// where A = sinus squared (difference in latitude / 2) + (cosine of latitude 1 * cosine of latitude 2 * sinus squared (difference in longitude / 2))
// and R = the circumference of the earth
// Reference: http://stackoverflow.com/questions/1420045/how-to-find-distance-from-the-latitude-and-longitude-of-two-locations
LatLong differenceIn = pointA - pointB;
double differenceInLat = DegreeToRadian(differenceIn.Latitude);
double differenceInLong = DegreeToRadian(differenceIn.Longitude);
double aInnerFormula = Math.Cos(DegreeToRadian(pointA.Latitude))
* Math.Cos(DegreeToRadian(pointB.Latitude))
* Math.Sin(differenceInLong / 2)
* Math.Sin(differenceInLong / 2);
double aFormula = (Math.Sin((differenceInLat) / 2) * Math.Sin((differenceInLat) / 2)) + (aInnerFormula);
return(Math.Round(avgRadiusOfEarth * 2 * Math.Atan2(Math.Sqrt(aFormula), Math.Sqrt(1 - aFormula)), 1));
}