Function explanation_stability 

pub fn explanation_stability(
    data: &FdMatrix,
    y: &[f64],
    scalar_covariates: Option<&FdMatrix>,
    ncomp: usize,
    n_boot: usize,
    seed: u64,
) -> Result<StabilityAnalysisResult, FdarError>

Bootstrap stability analysis of a linear functional regression.

Refits the model on n_boot bootstrap samples and reports variability of β(t), FPC coefficients, R², and importance rankings.

Errors

Returns FdarError::InvalidDimension if data has fewer than 4 rows, zero columns, or y.len() does not match the row count. Returns FdarError::InvalidParameter if n_boot < 2 or ncomp is zero. Returns FdarError::ComputationFailed if there are insufficient successful bootstrap refits.