Function fresnel_with 

pub fn fresnel_with<P, E, V, const NC: usize, const NS: usize, const NP: usize, const NQ: usize>(
    x: V,
    x0: E,
    map: E,
    cutoff: E,
    cheb_c: &[E; NC],
    cheb_s: &[E; NS],
    aux_p: &[E; NP],
    aux_q: &[E; NQ],
) -> (V, V)
where
    E: FloatElement,
    V: FloatVector<Element = E> + SpecializedTranscendentalMath<E>,
    P: Policy,

(S(x), C(x)), in SciPy’s order.

cheb_c and cheb_s are Chebyshev coefficients for C(x)/x and S(x)/x^3 in w = x^4 mapped onto [-1, 1] by w*map - 1. aux_p and aux_q are ascending monomial coefficients in u = 1/(pi x^2)^2. x0 is the crossover and cutoff the point above which both functions are 1/2.