Function predict_values 

pub fn predict_values(
    model: &SvmModel,
    x: &[SvmNode],
    dec_values: &mut [f64],
) -> f64

Compute decision values and return the predicted label/value.

For classification, dec_values receives nr_class * (nr_class - 1) / 2 pairwise decision values. For regression/one-class, a single value.

Returns the predicted label (classification) or function value (regression).

Matches LIBSVM’s svm_predict_values.