Function compute_statistics_for_sample 

pub fn compute_statistics_for_sample(
    lf: &LazyFrame,
    sample: &Sample,
    known_total: Option<usize>,
    options: ComputeOptions,
) -> Result<AnalysisResults>

compute_statistics_with_options over the rows a crate::sampling::Sample picks from lf, which is already cut to the sample’s scope.