public double Distance(City other)
{
double latdif = latitude - other.latitude;
double longdif = longitude - other.longitude;
return Math.Sqrt(latdif * latdif + longdif * longdif);
}
public City FindCentralCity()
{
double totLat = 0, totLong = 0;
// work out average latitude and longitude.
// This will be the center of the cities
for (int i = 0; i < cities.Length; i++)
{
totLat += cities[i].Latitude;
totLong += cities[i].Longitude;
}
totLat /= cities.Length;
totLong /= cities.Length;
// create a new city located at center
City central = new City("", totLat, totLong);
// find city closest to center
City closest = cities[0];
double tempDist, minDist = central.Distance(closest);
for (int i = 1; i < cities.Length; i++)
{
tempDist = central.Distance(cities[i]);
if (tempDist < minDist)
{
closest = cities[i];
minDist = tempDist;
}
}
return closest;
}
private void LoadCities(string cityFile)
{
cities = null;
StreamReader fin;
try
{
string line, name;
int cityCount = 0;
double lat, lng;
// get count of cities;
fin = new StreamReader(cityFile);
while (!fin.EndOfStream)
{
line = fin.ReadLine();
line.Trim();
if (line.Length > 0) cityCount++;
}
fin.Close();
// create cities array
cityCount /= 3;
if (cityCount == 0) return;
cities = new City[cityCount];
// load cities into array
fin = new StreamReader(cityFile);
for (int i = 0; i < cityCount; i++)
{
name = fin.ReadLine();
line = fin.ReadLine();
if (!double.TryParse(line, out lat)) break;
line = fin.ReadLine();
if (!double.TryParse(line, out lng)) break;
cities[i] = new City(name, lat, lng);
}
fin.Close();
}
catch (IOException e)
{
MessageBox.Show("Unable to read city file with the following error\n" + e.Message,
"City Central 2", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
