//calculate distance bewteen two GPS points
public double Distance(GPSPoint point)
{
double distance;
//earth radius in KM
const int earthRadius = 6371;
double deltaLongitude = Math.Abs(longitude - point.longitude);
double deltaSigma = Math.Acos(Math.Sin(point.latitude) * Math.Sin(latitude) +
Math.Cos(point.latitude) * Math.Cos(latitude) * Math.Cos(deltaLongitude));
distance = earthRadius * deltaSigma;
return distance;
}
public void DistanceReturnsCorrectDistance()
{
double latitude1 = 0.929302344;
double longitude1 = -0.108879486;
double latitude2 = 0.930927181;
double longitude2 = -0.109244654;
double expectedDistance = 10.444825879238;
GPSPoint point1 = new GPSPoint(latitude1, longitude1);
GPSPoint point2 = new GPSPoint(latitude2, longitude2);
double actualDistance = point1.Distance(point2);
Assert.AreEqual(expectedDistance, actualDistance, 0.000001, "Distance not calculated correctly");
}
static void Main(string[] args)
{
//URL where a text file containing JSON objects is located
const string URI = "https://gist.githubusercontent.com/brianw/19896c50afa89ad4dec3/raw/" +
"6c11047887a03483c50017c1d451667fd62a53ca/gistfile1.txt";
//initialize a GPSPoint with Dublin GPS coordiantes
GPSPoint DublinLocation = new GPSPoint(53.3381985 * Math.PI / 180,
-6.2592576 * Math.PI / 180);
//initialize a customer list using the classes UrlReader and JsonObjectReader
//that implements the interfaces IReader and IObjectreader respectively
try
{
SystemWebClientFactory myWebClientFactory = new SystemWebClientFactory();
UriToStream myUriToStream = new UriToStream(myWebClientFactory, URI);
StreamToStreamReader myStreamReader = new StreamToStreamReader(myUriToStream);
JsonDeserializer<Customer> myJsonDeserializer =
new JsonDeserializer<Customer>(myStreamReader);
List<Customer> customers = myJsonDeserializer.Deserialize().ToList();
//sort list of customers by User_id
List<Customer> sortedCustomers = (from c in customers orderby c.User_id select c)
.ToList<Customer>();
//print out the list of invited customers
foreach (Customer customer in sortedCustomers)
{
GPSPoint customerLocation = new GPSPoint(customer.Latitude * Math.PI / 180,
customer.Longitude * Math.PI / 180);
double customerDistance = customerLocation.Distance(DublinLocation);
if (customerDistance <= 100)
{
Console.WriteLine("User ID: {0} Customer Name: {1} Distance: {2}",
customer.User_id, customer.Name, customerDistance);
}
}
}
catch (Exception e)
{
Console.WriteLine(e);
}
Console.ReadLine();
}