Function polars_core::functions::cov_i

pub fn cov_i<T>(a: &ChunkedArray<T>, b: &ChunkedArray<T>) -> Option<f64>where
    T: PolarsIntegerType,
    T::Native: ToPrimitive,
    <T::Native as Simd>::Simd: Add<Output = <T::Native as Simd>::Simd> + Sum<T::Native> + SimdOrd<T::Native>,

Compute the covariance between two columns.