Function hermite_h 

pub fn hermite_h(n: usize, x: f64) -> f64

The physicists’ Hermite polynomial $H_{n}(x)$, by the recurrence $H_{n+1}(x) = 2x H_{n}(x) - 2n H_{n-1}(x)$ from $H_{0} = 1$, $H_{1} = 2x$ (Abramowitz & Stegun, eq. 22.7.13); the Hermite prototype of FBMC is a sum of $H_{4i}$.

Examples

use comnum_math::hermite_h;
assert_eq!(hermite_h(0, 0.3), 1.0);
assert_eq!(hermite_h(2, 0.5), 4.0 * 0.25 - 2.0);
assert!((hermite_h(4, 1.5) - (16.0 * 1.5f64.powi(4) - 48.0 * 1.5 * 1.5 + 12.0)).abs() < 1e-12);