Function conditional_permutation_importance 

pub fn conditional_permutation_importance(
    fit: &FregreLmResult,
    data: &FdMatrix,
    y: &[f64],
    scalar_covariates: Option<&FdMatrix>,
    n_bins: usize,
    n_perm: usize,
    seed: u64,
) -> Option<ConditionalPermutationImportanceResult>

Conditional permutation importance for a linear functional regression model.