Function mean

crates/openquant/src/strategy_risk.rs:285–287

(values: &[f64])

}

fn mean(values: &[f64]) -> f64 {
    values.iter().sum::<f64>() / values.len() as f64
}

fn std_dev(values: &[f64]) -> f64 {
    if values.len() < 2 {