Function bessel 

pub fn bessel(
    order: f64,
    z: Complex,
    kind: Bessel,
    spherical: bool,
    derivative: u8,
) -> Result<Complex>

Bessel value or one of its first two complex-argument derivatives.

kind selects J, Y, H1 or H2. spherical selects the spherical function of order order (j, y, h1 or h2): the cylindrical function of order order + 1/2 times sqrt(pi / (2z)). derivative is 0, 1 or 2, always with respect to z. Spherical regular functions use analytic origin limits.

Upstream: treams.special.jv, yv, hankel1, hankel2 and with spherical spherical_jn, spherical_yn, spherical_hankel1, spherical_hankel2; their _d variants for derivative = 1. treams has no second derivative.