/// <summary>
/// Calculate the distance between two sets of coordinates.
/// <param name="originLatitude">The latitude of the origin location in decimal notation</param>
/// <param name="originLongitude">The longitude of the origin location in decimal notation</param>
/// <param name="destinationLatitude">The latitude of the destination location in decimal notation</param>
/// <param name="destinationLongitude">The longitude of the destination location in decimal notation</param>
/// <param name="decimalPlaces">The number of decimal places to round the return value to</param>
/// <param name="distanceUnit">The unit of distance</param>
/// <returns>
/// A <see cref="double" /> value representing the distance in miles from the origin to the destination
/// coordinate
/// </returns>
/// </summary>
public static double GetDistance(
double originLatitude,
double originLongitude,
double destinationLatitude,
double destinationLongitude,
int decimalPlaces = 1,
DistanceUnit distanceUnit = DistanceUnit.Miles)
{
if (!CoordinateValidator.Validate(originLatitude, originLongitude))
{
throw new ArgumentException("Invalid origin coordinates supplied.");
}
if (!CoordinateValidator.Validate(destinationLatitude, destinationLongitude))
{
throw new ArgumentException("Invalid destination coordinates supplied.");
}
double radius = GetRadius(distanceUnit);
return(Math.Round(
radius * 2 *
Math.Asin(
Math.Min(
1,
Math.Sqrt(
Math.Pow(Math.Sin(originLatitude.DiffRadian(destinationLatitude) / 2.0), 2.0) +
Math.Cos(originLatitude.ToRadian()) * Math.Cos(destinationLatitude.ToRadian()) *
Math.Pow(
Math.Sin(originLongitude.DiffRadian(destinationLongitude) / 2.0),
2.0)))),
decimalPlaces));
}
/// <summary>
/// Gets the cardinal or ordinal direction from the origin point to the destination point
/// </summary>
/// <param name="originLatitude">The latitude of the origin location in decimal notation</param>
/// <param name="originLongitude">The longitude of the origin location in decimal notation</param>
/// <param name="destinationLatitude">The latitude of the destination location in decimal notation</param>
/// <param name="destinationLongitude">The longitude of the destination location in decimal notation</param>
/// <returns>A string value indicating the cardinal or ordinal direction from the origin to the desintation point</returns>
public static string GetDirection(double originLatitude, double originLongitude, double destinationLatitude, double destinationLongitude)
{
if (!CoordinateValidator.Validate(originLatitude, originLongitude))
{
throw new ArgumentException("Invalid origin coordinates supplied.");
}
if (!CoordinateValidator.Validate(destinationLatitude, destinationLongitude))
{
throw new ArgumentException("Invalid destination coordinates supplied.");
}
double bearing = GetBearing(originLatitude, originLongitude, destinationLatitude, destinationLongitude);
if (bearing >= 337.5 || bearing <= 22.5)
{
return("N");
}
if (bearing > 22.5 && bearing <= 67.5)
{
return("NE");
}
if (bearing > 67.5 && bearing <= 112.5)
{
return("E");
}
if (bearing > 112.5 && bearing <= 157.5)
{
return("SE");
}
if (bearing > 157.5 && bearing <= 202.5)
{
return("S");
}
if (bearing > 202.5 && bearing <= 247.5)
{
return("SW");
}
if (bearing > 247.5 && bearing <= 292.5)
{
return("W");
}
if (bearing > 292.5 && bearing < 337.5)
{
return("NW");
}
return(string.Empty);
}
/// <summary>
/// Creates a new CoordinateBoundary object
/// </summary>
/// <param name="latitude">The origin point latitude in decimal notation</param>
/// <param name="longitude">The origin point longitude in decimal notation</param>
/// <param name="distance">The distance from the origin point in statute miles</param>
/// <param name="distanceUnit">The unit of distance</param>
public CoordinateBoundaries(double latitude, double longitude, double distance, DistanceUnit distanceUnit = DistanceUnit.Miles)
{
if (!CoordinateValidator.Validate(latitude, longitude))
{
throw new ArgumentException("Invalid coordinates supplied.");
}
this.latitude = latitude;
this.longitude = longitude;
this.distance = distance;
this.distanceUnit = distanceUnit;
Calculate();
}
/// <summary>
/// Calculates the bearing, in degrees between two geographic points
/// </summary>
/// <param name="originLatitude">The latitude of the origin location in decimal notation</param>
/// <param name="originLongitude">The longitude of the origin location in decimal notation</param>
/// <param name="destinationLatitude">The latitude of the destination location in decimal notation</param>
/// <param name="destinationLongitude">The longitude of the destination location in decimal notation</param>
/// <returns>A <see cref="double" /> value indicating the bearing from the origin to the destination</returns>
public static double GetBearing(double originLatitude, double originLongitude, double destinationLatitude, double destinationLongitude)
{
if (!CoordinateValidator.Validate(originLatitude, originLongitude))
{
throw new ArgumentException("Invalid origin coordinates supplied.");
}
if (!CoordinateValidator.Validate(destinationLatitude, destinationLongitude))
{
throw new ArgumentException("Invalid destination coordinates supplied.");
}
var destinationRadian = (destinationLongitude - originLongitude).ToRadian();
var destinationPhi = Math.Log(Math.Tan(destinationLatitude.ToRadian() / 2 + Math.PI / 4) / Math.Tan(originLatitude.ToRadian() / 2 + Math.PI / 4));
if (Math.Abs(destinationRadian) > Math.PI)
{
destinationRadian = destinationRadian > 0
? -(2 * Math.PI - destinationRadian)
: 2 * Math.PI + destinationRadian;
}
return(Math.Atan2(destinationRadian, destinationPhi).ToBearing());
}
