Function mean

pub fn mean<T, Scalar, Out>(iter: T) -> Out
where
    T: IntoIterator,
    T::Item: IntoAngle<Rad<Scalar>, OutputScalar = Scalar>,
    Scalar: Float + AddAssign,
    Out: Angle<Scalar = Scalar> + FromAngle<Rad<Scalar>>,

Compute the mean of a collection of angles.

Note that because angles are circular, a standard summation and dividing by len() is not valid, even if all angles are normalized.