Method mean

datafusion/expr-common/src/statistics.rs:121–129

Extracts the mean value of this uncertain quantity, depending on its distribution: - A [`Uniform`] distribution's interval determines its mean value, which is the arithmetic average of the interval endpoints. - An [`Exponential`] distribution's mean is calculable by the formula `offset + 1 / λ`, where `λ` is the (non-negative) rate. - A [`Gaussian`] distribution contains the mean explicitly. - A [

(&self)

    /// - A [`Generic`] distribution _may_ have it explicitly, or this information
    ///   may be absent.
    pub fn mean(&self) -> Result<ScalarValue> {
        match &self {
            Uniform(u) => u.mean(),
            Exponential(e) => e.mean(),
            Gaussian(g) => Ok(g.mean().clone()),
            Bernoulli(b) => Ok(b.mean().clone()),
            Generic(u) => Ok(u.mean().clone()),
        }
    }

    /// Extracts the median value of this uncertain quantity, depending on its
    /// distribution: