3.2.1.5. HankelH_Asym.m

Calculate the Hankel function \(H_m(z)\) using the asymptotic method.

3.2.1.5.1. Syntax

H = HankelH_Asym(m, z)

3.2.1.5.2. Output arguments

H\(H_m(z)\).

3.2.1.5.3. Input arguments

3.2.1.5.3.1. Mandatory arguments

m — order

z — the argument \(z\)

3.2.1.5.3.2. Optional arguments

approx_order

  • \(K\in \mathbb{N}\) — Calculate the Hankel function using the asymptotic expansion given by Eq. (3.2.2), see Eq. (10.17.5) in Olver et al. [5].

(3.2.2)\[H_m^{(1)}(z) \sim \sqrt{\frac{2}{\pi z}} \mathrm{e}^{-\mathrm{i}\omega} \sum_{k=0}^K \mathrm{i}^k \frac{a_k(m)}{z^k}\]
  • 0 — The returned result reduces to Eq. (3.2.3), see Eq. (10.2.5) in Olver et al. [5].

(3.2.3)\[H_m^{(1)}(z) \sim \sqrt{\frac{2}{\mathrm{i}\pi z}} \frac{\mathrm{e}^{\mathrm{i}z}}{\mathrm{i}^m}\]

3.2.1.5.4. Dependencies

NA