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



Bits error versus k



Bits error versus n
Results
Initial program 0.4
rmApplied add-sqr-sqrt0.5
Applied associate-*l*0.5
Final simplification0.5
herbie shell --seed 2020060
(FPCore (k n)
:name "Migdal et al, Equation (51)"
:precision binary64
(* (/ 1 (sqrt k)) (pow (* (* 2 PI) n) (/ (- 1 k) 2))))