\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}\left(\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{\frac{1 - k}{2}}{2}\right)}\right) \cdot {\left({2}^{\left(\frac{1 - k}{2}\right)} \cdot {\left(\pi \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}\right)}^{\frac{1}{2}}double f(double k, double n) {
double r64609 = 1.0;
double r64610 = k;
double r64611 = sqrt(r64610);
double r64612 = r64609 / r64611;
double r64613 = 2.0;
double r64614 = atan2(1.0, 0.0);
double r64615 = r64613 * r64614;
double r64616 = n;
double r64617 = r64615 * r64616;
double r64618 = r64609 - r64610;
double r64619 = r64618 / r64613;
double r64620 = pow(r64617, r64619);
double r64621 = r64612 * r64620;
return r64621;
}
double f(double k, double n) {
double r64622 = 1.0;
double r64623 = k;
double r64624 = sqrt(r64623);
double r64625 = r64622 / r64624;
double r64626 = 2.0;
double r64627 = atan2(1.0, 0.0);
double r64628 = r64626 * r64627;
double r64629 = n;
double r64630 = r64628 * r64629;
double r64631 = r64622 - r64623;
double r64632 = r64631 / r64626;
double r64633 = 2.0;
double r64634 = r64632 / r64633;
double r64635 = pow(r64630, r64634);
double r64636 = r64625 * r64635;
double r64637 = pow(r64626, r64632);
double r64638 = r64627 * r64629;
double r64639 = pow(r64638, r64632);
double r64640 = r64637 * r64639;
double r64641 = 0.5;
double r64642 = pow(r64640, r64641);
double r64643 = r64636 * r64642;
return r64643;
}



Bits error versus k



Bits error versus n
Results
Initial program 0.4
rmApplied sqr-pow0.5
Applied associate-*r*0.5
rmApplied div-inv0.5
Applied pow-unpow0.5
Simplified0.5
rmApplied add-cube-cbrt0.5
Applied associate-*l*0.5
rmApplied unpow-prod-down0.5
Simplified0.4
Final simplification0.4
herbie shell --seed 2019323
(FPCore (k n)
:name "Migdal et al, Equation (51)"
:precision binary64
(* (/ 1 (sqrt k)) (pow (* (* 2 PI) n) (/ (- 1 k) 2))))