Function percentile_by

pub fn percentile_by(
    values: &mut OwnedClusterList,
    target: impl OrderedListIndex,
    pivot_fn: &mut impl FnMut(&ClusterList<'_>) -> f64,
    compare: &mut impl FnMut(f64, f64) -> Ordering,
) -> MeanValue<f64>

Same as percentile but with a custom comparator function.