Function math::stats::correlation::weighted_correlation

pub fn weighted_correlation<T, V, I: Iterator<Item = T>, F1, F2>(
    get_iter: F1, 
    get_a_b_weight: F2
) -> f64 where
    V: Copy + ToPrimitive,
    F1: Fn() -> I,
    F2: Fn(T) -> (V, V, V), 

The weights and values are of type T.