/// <summary>
/// ''' Calculates the angle between the two directions starting from the position
/// ''' and ending in the start and end point of the stretch.
/// ''' </summary>
/// ''' <param name="at">The <see cref="Position">position</see> to get the angle for.</param>
/// ''' <returns>The angle between the two directions starting from the position
/// ''' and ending in the start and end point of the stretch.</returns>
/// ''' <remarks></remarks>
public static Angle MinAngle(this Stretch me, Position at)
{
var a1 = Stretch.Between(at, me.From).Direction;
var a2 = Stretch.Between(at, me.To).Direction;
return(a1.Min(a2));
}
public void JsonSerializationAndDeserializationWorks()
{
var target = Stretch.Between(Position.FromDegrees(58.1, 11.9), Position.FromDegrees(59.1, 12.9));
var actual = SerializationTester <Stretch> .JsonSerializeAndDeserialize(target);
Assert.AreEqual(target, actual);
}
public void Operators()
{
Assert.IsTrue(Stretch.Between(TestData.Stockholm, TestData.Wellington) == Stretch.Between(TestData.Stockholm, TestData.Wellington));
Assert.IsFalse(Stretch.Between(TestData.Stockholm, TestData.Wellington) == Stretch.Between(TestData.Hövik, TestData.Höviksnäs));
Assert.IsFalse(Stretch.Between(TestData.Stockholm, TestData.Wellington) != Stretch.Between(TestData.Stockholm, TestData.Wellington));
Assert.IsTrue(Stretch.Between(TestData.Stockholm, TestData.Wellington) != Stretch.Between(TestData.Hövik, TestData.Höviksnäs));
}
public void CreateWithDistanceCalculator()
{
var target = Stretch.Between(TestData.Hövik, TestData.Höviksnäs, new HaversineDistanceCalculator());
Assert.AreEqual(TestData.Hövik, target.From);
Assert.AreEqual(TestData.Höviksnäs, target.To);
}
public void IsInverse()
{
var target = Stretch.Between(TestData.Hövik, TestData.Höviksnäs);
var actual = target.Inverse;
Assert.AreEqual(target.To, actual.From);
Assert.AreEqual(target.From, actual.To);
}
public void OnTrackDistance()
{
var s = Stretch.Between(TestData.Hövik, TestData.Höviksnäs);
Assert.AreEqual(Distance.FromMeters(62.640), s.OnTrackDistance(Position.FromDegrees(58.033668, 11.743887)));
Assert.AreEqual(Distance.FromMeters(311.088), s.OnTrackDistance(Position.FromDegrees(58.033296, 11.750197)));
Assert.AreEqual(Distance.FromMeters(598.805), s.OnTrackDistance(Position.FromDegrees(58.032905, 11.755030)));
}
public void CrossTrackDistance()
{
var s = Stretch.Between(TestData.Hövik, TestData.Höviksnäs);
Assert.AreEqual(Distance.FromMeters(20.950), s.CrossTrackDistance(Position.FromDegrees(58.033668, 11.743887)));
Assert.AreEqual(Distance.FromMeters(15.855), s.CrossTrackDistance(Position.FromDegrees(58.033296, 11.750197)));
Assert.AreEqual(Distance.FromMeters(23.632), s.CrossTrackDistance(Position.FromDegrees(58.032905, 11.755030)));
}
/// <summary>
/// ''' The along-track distance, calculated from the start point to the closest point on the path to the given point.
/// ''' </summary>
/// ''' <param name="at">The <see cref="Position">position</see> to caclulate the on track distance for.</param>
/// ''' <returns>The on track distance from the start of the stretch.</returns>
/// ''' <remarks></remarks>
public static Distance OnTrackDistance(this Stretch me, Position at)
{
const double r = EarthMeanRadiusMeters / 1000;
var s = Stretch.Between(me.From, at);
var d13 = s.Distance.Meters;
var dXt = me.CrossTrackDistance(at).Meters;
var d = Acos(Cos(d13 / r) / Cos(dXt / r)) * r;
return(Distance.FromMeters(Abs(d)));
}
public void LongStretchHaveCorrectProperties()
{
var target = Stretch.Between(TestData.Stockholm, TestData.Wellington);
Assert.AreEqual(17445.0, target.Distance.Kilometers, 0.1);
Assert.AreEqual(127.296, target.Direction.Degrees, 0.001);
Assert.AreEqual(48.853, target.InitialBearing.Degrees, 0.001);
Assert.AreEqual(149.276, target.FinalBearing.Degrees, 0.001);
Assert.IsFalse(target.IsEastWestLine);
}
public void ShortStretchHaveCorrectProperties()
{
var target = Stretch.Between(TestData.Hövik, TestData.Höviksnäs);
Assert.AreEqual(0.5620, target.Distance.Kilometers, 0.001);
Assert.AreEqual(97.137, target.Direction.Degrees, 0.001);
Assert.AreEqual(97.133, target.InitialBearing.Degrees, 0.001);
Assert.AreEqual(97.141, target.FinalBearing.Degrees, 0.001);
//Assert.IsFalse(target.IsEastWestLine);
}
/// <summary>
/// The distance of a point from a great-circle path (sometimes called cross track error).
/// </summary>
/// <param name="at"></param>
/// <returns></returns>
public static Distance CrossTrackDistance(this Stretch me, Position at)
{
const double R = EarthMeanRadiusMeters;
var s = Stretch.Between(me.From, at);
var δ13 = s.Distance.Meters;
var θ13 = s.InitialBearing.Radians;
var θ12 = me.InitialBearing.Radians;
var d = Asin(Sin(δ13 / R) * Sin(θ13 - θ12)) * R;
return(Distance.FromMeters(Abs(d)));
}
public static IEnumerable <Stretch> EnclosingSides(this Position[] positions) => positions.Select((v, i) => Stretch.Between(v, positions[i > positions.Length - 1 ? 0 : i]));
public void MinAngle()
{
var s = Stretch.Between(TestData.Hövik, TestData.Höviksnäs);
Assert.AreEqual(Angle.FromDegrees(173.471107), s.MinAngle(Position.FromDegrees(58.033296, 11.750197)));
}
public void EqualsIsCorrect()
{
Assert.AreEqual(Stretch.Between(TestData.Stockholm, TestData.Wellington), Stretch.Between(TestData.Stockholm, TestData.Wellington));
Assert.AreNotEqual(Stretch.Between(TestData.Stockholm, TestData.Wellington), Stretch.Between(TestData.Hövik, TestData.Höviksnäs));
Assert.AreNotEqual(Stretch.Between(TestData.Stockholm, TestData.Wellington), new object());
}
public void IsZero()
{
Assert.IsTrue(Stretch.Between(TestData.Hövik, TestData.Hövik).IsZero);
}
public void IsEastWestLine()
{
var target = Stretch.Between(Position.FromDegrees(50, -4), Position.FromDegrees(50, 87));
Assert.IsTrue(target.IsEastWestLine);
}
