Function abs2_frule 

pub fn abs2_frule<S: ScalarAd>(x: S, dx: S) -> (S::Real, S::Real)

Forward rule for abs2.

Examples

use chainrules::abs2_frule;
use num_complex::Complex64;

let z = Complex64::new(3.0, 4.0);
let dz = Complex64::new(1.0, -2.0);
let (y, dy) = abs2_frule(z, dz);
assert_eq!(y, 25.0);
assert_eq!(dy, -10.0);