Function average 

pub fn average<T: Scalar + Element>(
    data: &[T],
    weights: &[T],
    axes: &Axes,
    mappings: [&Mapping; 2],
) -> Vec<T>
where
    Sum: Reduction<T, Total = T>,

Weighted means. The two mappings broadcast data and weights into an array of dims. Weights may be real or complex; a zero total weight gives the ordinary floating-point quotient.