\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(n \cdot \pi\right)}^{\left(\frac{1 - k}{2}\right)}\right)}^{\frac{1}{2}}double f(double k, double n) {
double r84386 = 1.0;
double r84387 = k;
double r84388 = sqrt(r84387);
double r84389 = r84386 / r84388;
double r84390 = 2.0;
double r84391 = atan2(1.0, 0.0);
double r84392 = r84390 * r84391;
double r84393 = n;
double r84394 = r84392 * r84393;
double r84395 = r84386 - r84387;
double r84396 = r84395 / r84390;
double r84397 = pow(r84394, r84396);
double r84398 = r84389 * r84397;
return r84398;
}
double f(double k, double n) {
double r84399 = 1.0;
double r84400 = k;
double r84401 = sqrt(r84400);
double r84402 = r84399 / r84401;
double r84403 = 2.0;
double r84404 = atan2(1.0, 0.0);
double r84405 = r84403 * r84404;
double r84406 = n;
double r84407 = r84405 * r84406;
double r84408 = r84399 - r84400;
double r84409 = r84408 / r84403;
double r84410 = 2.0;
double r84411 = r84409 / r84410;
double r84412 = pow(r84407, r84411);
double r84413 = r84402 * r84412;
double r84414 = pow(r84403, r84409);
double r84415 = r84406 * r84404;
double r84416 = pow(r84415, r84409);
double r84417 = r84414 * r84416;
double r84418 = 0.5;
double r84419 = pow(r84417, r84418);
double r84420 = r84413 * r84419;
return r84420;
}



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 unpow-prod-down0.4
Final simplification0.4
herbie shell --seed 2019323 +o rules:numerics
(FPCore (k n)
:name "Migdal et al, Equation (51)"
:precision binary64
(* (/ 1 (sqrt k)) (pow (* (* 2 PI) n) (/ (- 1 k) 2))))