\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 r64656 = 1.0;
double r64657 = k;
double r64658 = sqrt(r64657);
double r64659 = r64656 / r64658;
double r64660 = 2.0;
double r64661 = atan2(1.0, 0.0);
double r64662 = r64660 * r64661;
double r64663 = n;
double r64664 = r64662 * r64663;
double r64665 = r64656 - r64657;
double r64666 = r64665 / r64660;
double r64667 = pow(r64664, r64666);
double r64668 = r64659 * r64667;
return r64668;
}
double f(double k, double n) {
double r64669 = 1.0;
double r64670 = k;
double r64671 = sqrt(r64670);
double r64672 = r64669 / r64671;
double r64673 = 2.0;
double r64674 = atan2(1.0, 0.0);
double r64675 = r64673 * r64674;
double r64676 = n;
double r64677 = r64675 * r64676;
double r64678 = r64669 - r64670;
double r64679 = r64678 / r64673;
double r64680 = 2.0;
double r64681 = r64679 / r64680;
double r64682 = pow(r64677, r64681);
double r64683 = r64672 * r64682;
double r64684 = pow(r64673, r64679);
double r64685 = r64674 * r64676;
double r64686 = pow(r64685, r64679);
double r64687 = r64684 * r64686;
double r64688 = 0.5;
double r64689 = pow(r64687, r64688);
double r64690 = r64683 * r64689;
return r64690;
}



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))))