/// <summary>
/// Distances the between.
/// </summary>
/// <param name="point1">The point1.</param>
/// <param name="point2">The point2.</param>
/// <param name="returnType">Type of the return.</param>
/// <returns></returns>
public static double DistanceBetween(LatitudeLongitudePoint point1, LatitudeLongitudePoint point2, DistanceType returnType)
{
// see http://www.mathforum.com/library/drmath/view/51711.html
// TODO is this really correct, or do I have to first convert decimal to degrees and then to radians?
if (point1.Latitude == point2.Latitude)
{
return(0);
}
double a = point1.Latitude / 57.29577951D;
double b = point1.Longitude / 57.29577951D;
double c = point2.Latitude / 57.29577951D;
double d = point2.Longitude / 57.29577951D;
double earthRadius = (returnType == DistanceType.StatuteMiles ? GlobalConstants.EarthEquatorialRadiusInStatuteMiles : (returnType == DistanceType.NauticalMiles ? GlobalConstants.EarthEquatorialRadiusInNauticalMiles : GlobalConstants.EarthEquatorialRadiusInKilometers));
double sina = Math.Sin(a);
double sinc = Math.Sin(c);
double cosa = Math.Cos(a);
double cosc = Math.Cos(c);
double cosbd = Math.Cos(b - d);
double ans1 = ((sina * sinc) + (cosa * cosc * cosbd));
if (ans1 > 1D)
{
return(earthRadius * Math.Acos(1D));
}
else
{
return(earthRadius * Math.Acos(ans1));
}
}
/// <summary>
/// Parses the specified latitude.
/// </summary>
/// <param name="latitude">The latitude.</param>
/// <param name="longitude">The longitude.</param>
/// <returns></returns>
public static LatitudeLongitudePoint Parse(string latitude, string longitude)
{
if (!(latitude == null || longitude == null || latitude.ToLower() == "na" || longitude.ToLower() == "na"))
{
LatitudeLongitudePoint ret = new LatitudeLongitudePoint();
Regex r = new Regex(@"(\d+)\.(\d+)(\.(\d+))?(\w)");
double degrees, minutes, seconds = 0;
Match m = r.Match(latitude);
if (m.Success)
{
degrees = double.Parse(m.Groups[1].Value);
minutes = double.Parse(m.Groups[2].Value);
seconds = m.Groups[3].Success ? double.Parse(m.Groups[3].Value) : 0;
ret.Latitude = degrees + (minutes / 60D) + (seconds / 3600D);
if (m.Groups[5].Value.ToLower() == "s")
{
ret.Latitude *= -1;
}
}
else
{
throw new Exception("Unsupported parse type!");
}
m = r.Match(longitude);
if (m.Success)
{
degrees = double.Parse(m.Groups[1].Value);
minutes = double.Parse(m.Groups[2].Value);
seconds = m.Groups[3].Success ? double.Parse(m.Groups[3].Value) : 0;
ret.Longitude = degrees + (minutes / 60D) + (seconds / 3600D);
if (m.Groups[5].Value.ToLower() == "w")
{
ret.Longitude *= -1;
}
}
else
{
throw new Exception("Unsupported parse type!");
}
return(ret);
}
return(null);
}
/// <summary>
/// Returns the distance between two latitude/longitude points, in miles.
/// </summary>
/// <param name="point1"></param>
/// <param name="point2"></param>
/// <returns></returns>
public static double DistanceBetween(LatitudeLongitudePoint point1, LatitudeLongitudePoint point2)
{
return(DistanceBetween(point1, point2, DistanceType.StatuteMiles));
}