Function petal_neighbors::distance::euclidean_reduced

#[must_use]pub fn euclidean_reduced<A>(x1: &ArrayView1<'_, A>, x2: &ArrayView1<'_, A>) -> A where
    A: Float + Zero + AddAssign, 

Euclidean distance before taking a squre root. Used as a lightweight version of euclidean for relative comparisions. euclidean: #method.euclidean