Function precision_recall_curve 

pub fn precision_recall_curve(
    scores: &[f64],
    labels: &[bool],
) -> Result<PrCurve, StatsError>

Compute a precision–recall curve from predicted scores and true binary labels (true = positive class). Higher scores are “more positive”.

Errors

• StatsError::LengthMismatch if the inputs differ in length.
• StatsError::EmptyInput if empty.
• StatsError::NoPositiveLabels if there are no positives, since recall is 0/0. (Unlike ROC, PR does not require any negatives.)