Function integrate 

pub fn integrate<const N: usize, F>(
    f: F,
    a: f64,
    b: f64,
    tolerance: Tolerance,
) -> Result<Integral<N>, CoreError>
where
    F: FnMut(f64) -> [f64; N],

Integrates the vector-valued f over [a, b] to tolerance.

a > b integrates backwards (the result changes sign) and a == b gives zeros. Integrands whose components differ in scale should be scaled to order one first, so one absolute tolerance suits them all.

Errors

• CoreError::Domain if a or b is not finite, or the tolerance is negative or NaN, or allows no subinterval.
• CoreError::QuadratureNotFinite if f returns NaN or an infinity (for example at an endpoint singularity the rule’s nodes happen to reach; the nodes never include the ends).
• CoreError::QuadratureDidNotConverge if tolerance.max_intervals subintervals don’t meet the tolerance.