\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}\frac{{2}^{\left(\frac{1}{2} - \frac{k}{2}\right)}}{{\pi}^{\left(\frac{k}{2}\right)}} \cdot \frac{{n}^{\left(\frac{1}{2} - \frac{k}{2}\right)}}{\frac{\sqrt{k}}{{\pi}^{\frac{1}{2}}}}double f(double k, double n) {
double r28919130 = 1.0;
double r28919131 = k;
double r28919132 = sqrt(r28919131);
double r28919133 = r28919130 / r28919132;
double r28919134 = 2.0;
double r28919135 = atan2(1.0, 0.0);
double r28919136 = r28919134 * r28919135;
double r28919137 = n;
double r28919138 = r28919136 * r28919137;
double r28919139 = r28919130 - r28919131;
double r28919140 = r28919139 / r28919134;
double r28919141 = pow(r28919138, r28919140);
double r28919142 = r28919133 * r28919141;
return r28919142;
}
double f(double k, double n) {
double r28919143 = 2.0;
double r28919144 = 0.5;
double r28919145 = k;
double r28919146 = r28919145 / r28919143;
double r28919147 = r28919144 - r28919146;
double r28919148 = pow(r28919143, r28919147);
double r28919149 = atan2(1.0, 0.0);
double r28919150 = pow(r28919149, r28919146);
double r28919151 = r28919148 / r28919150;
double r28919152 = n;
double r28919153 = pow(r28919152, r28919147);
double r28919154 = sqrt(r28919145);
double r28919155 = pow(r28919149, r28919144);
double r28919156 = r28919154 / r28919155;
double r28919157 = r28919153 / r28919156;
double r28919158 = r28919151 * r28919157;
return r28919158;
}



Bits error versus k



Bits error versus n
Results
Initial program 0.4
Simplified0.3
rmApplied unpow-prod-down0.4
Applied associate-/l*0.4
rmApplied pow-sub0.4
Applied associate-/r/0.4
Applied unpow-prod-down0.5
Applied times-frac0.5
Final simplification0.5
herbie shell --seed 2019168 +o rules:numerics
(FPCore (k n)
:name "Migdal et al, Equation (51)"
(* (/ 1 (sqrt k)) (pow (* (* 2 PI) n) (/ (- 1 k) 2))))