Function functional_saliency 

pub fn functional_saliency(
    fit: &FregreLmResult,
    data: &FdMatrix,
    scalar_covariates: Option<&FdMatrix>,
) -> Result<FunctionalSaliencyResult, FdarError>

Functional saliency maps for a linear functional regression model.

Lifts FPC-level SHAP attributions to the function domain via the rotation matrix.

Errors

Returns FdarError::InvalidDimension if data has zero rows or its column count does not match fit.fpca.mean. Returns FdarError::InvalidParameter if fit.ncomp is zero.