\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}1 \cdot {\left(\frac{\sqrt{k}}{{\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}}\right)}^{\left(-1\right)}double code(double k, double n) {
return ((1.0 / sqrt(k)) * pow(((2.0 * ((double) M_PI)) * n), ((1.0 - k) / 2.0)));
}
double code(double k, double n) {
return (1.0 * pow((sqrt(k) / pow(((2.0 * ((double) M_PI)) * n), ((1.0 - k) / 2.0))), -1.0));
}



Bits error versus k



Bits error versus n
Results
Initial program 0.4
rmApplied div-inv0.4
Applied associate-*l*0.4
Simplified0.3
rmApplied clear-num0.4
rmApplied pow10.4
Applied pow-flip0.4
Final simplification0.4
herbie shell --seed 2020053
(FPCore (k n)
:name "Migdal et al, Equation (51)"
:precision binary64
(* (/ 1 (sqrt k)) (pow (* (* 2 PI) n) (/ (- 1 k) 2))))