/// <summary>
/// Projects the given vector on this vector.
/// </summary>
/// <param name="source">The vector to project onto this vector.</param>
/// <returns>The projected vector.</returns>
/// <remarks>The projected vector will be in the same direction as this vector. The magnitude of the vector
/// will be the magnitude of the given vector in this direction.</remarks>
/// <exception cref="ArgumentNullException">Thrown when source is a null reference.</exception>
public XYZ Project(XYZ source)
{
NullCheck(source, "source");
return((DotProduct(source) / source.GetLength()) * Normalize());
}
/// <summary>
/// Returns the angle between this vector and the specified vector.
/// </summary>
/// <param name="source">The specified vector.</param>
/// <returns>The real number between 0 and PI equal to the angle between the two vectors in
/// radians.</returns>
/// <remarks>The angle between the two vectors is measured in the plane spanned by them.</remarks>
/// <exception cref="ArgumentNullException">Thrown when source is a null reference.</exception>"
public double AngleTo(XYZ source)
{
NullCheck(source, "source");
return(Math.Acos(DotProduct(source) / (GetLength() * source.GetLength())));
}