/// <summary>
/// Decodes an AzAlt Coordinate from it's cartesean equivalent
/// Note: This method should ONLY be used to decode cartesean coordinates
/// that were originally generated from an AzAltCoordinate of from values
/// interpolated from those originally generated from AzAltCoordinates.
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <returns></returns>
public static AltAzCoordinate FromCartesean(double x, double y)
{
double az = 0.0;
double alt = Math.Sqrt((x * x) + (y * y));
if (x > 0)
{
az = Math.Atan(y / x);
}
if (x < 0)
{
if (y >= 0)
{
az = Math.Atan(y / x) + Math.PI;
}
else
{
az = Math.Atan(y / x) - Math.PI;
}
}
if (x == 0)
{
if (y > 0)
{
az = Math.PI / 2.0;
}
else
{
az = -1 * (Math.PI / 2.0);
}
}
return(new AltAzCoordinate((alt - ALT_OFFSET), AstroConvert.RangeAzimuth(AstroConvert.RadToDeg(az))));
}