
(FPCore (k n) :precision binary64 (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0))))
double code(double k, double n) {
return (1.0 / sqrt(k)) * pow(((2.0 * ((double) M_PI)) * n), ((1.0 - k) / 2.0));
}
public static double code(double k, double n) {
return (1.0 / Math.sqrt(k)) * Math.pow(((2.0 * Math.PI) * n), ((1.0 - k) / 2.0));
}
def code(k, n): return (1.0 / math.sqrt(k)) * math.pow(((2.0 * math.pi) * n), ((1.0 - k) / 2.0))
function code(k, n) return Float64(Float64(1.0 / sqrt(k)) * (Float64(Float64(2.0 * pi) * n) ^ Float64(Float64(1.0 - k) / 2.0))) end
function tmp = code(k, n) tmp = (1.0 / sqrt(k)) * (((2.0 * pi) * n) ^ ((1.0 - k) / 2.0)); end
code[k_, n_] := N[(N[(1.0 / N[Sqrt[k], $MachinePrecision]), $MachinePrecision] * N[Power[N[(N[(2.0 * Pi), $MachinePrecision] * n), $MachinePrecision], N[(N[(1.0 - k), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (k n) :precision binary64 (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0))))
double code(double k, double n) {
return (1.0 / sqrt(k)) * pow(((2.0 * ((double) M_PI)) * n), ((1.0 - k) / 2.0));
}
public static double code(double k, double n) {
return (1.0 / Math.sqrt(k)) * Math.pow(((2.0 * Math.PI) * n), ((1.0 - k) / 2.0));
}
def code(k, n): return (1.0 / math.sqrt(k)) * math.pow(((2.0 * math.pi) * n), ((1.0 - k) / 2.0))
function code(k, n) return Float64(Float64(1.0 / sqrt(k)) * (Float64(Float64(2.0 * pi) * n) ^ Float64(Float64(1.0 - k) / 2.0))) end
function tmp = code(k, n) tmp = (1.0 / sqrt(k)) * (((2.0 * pi) * n) ^ ((1.0 - k) / 2.0)); end
code[k_, n_] := N[(N[(1.0 / N[Sqrt[k], $MachinePrecision]), $MachinePrecision] * N[Power[N[(N[(2.0 * Pi), $MachinePrecision] * n), $MachinePrecision], N[(N[(1.0 - k), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}
\end{array}
(FPCore (k n) :precision binary64 (/ (pow (* (* PI 2.0) n) (/ (- 1.0 k) 2.0)) (sqrt k)))
double code(double k, double n) {
return pow(((((double) M_PI) * 2.0) * n), ((1.0 - k) / 2.0)) / sqrt(k);
}
public static double code(double k, double n) {
return Math.pow(((Math.PI * 2.0) * n), ((1.0 - k) / 2.0)) / Math.sqrt(k);
}
def code(k, n): return math.pow(((math.pi * 2.0) * n), ((1.0 - k) / 2.0)) / math.sqrt(k)
function code(k, n) return Float64((Float64(Float64(pi * 2.0) * n) ^ Float64(Float64(1.0 - k) / 2.0)) / sqrt(k)) end
function tmp = code(k, n) tmp = (((pi * 2.0) * n) ^ ((1.0 - k) / 2.0)) / sqrt(k); end
code[k_, n_] := N[(N[Power[N[(N[(Pi * 2.0), $MachinePrecision] * n), $MachinePrecision], N[(N[(1.0 - k), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{{\left(\left(\pi \cdot 2\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}}{\sqrt{k}}
\end{array}
Initial program 99.2%
lift-*.f64N/A
lift-/.f64N/A
lift-sqrt.f64N/A
lift-pow.f64N/A
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
lift--.f64N/A
lift-/.f64N/A
associate-*l/N/A
lower-/.f64N/A
Applied rewrites99.3%
Final simplification99.3%
(FPCore (k n) :precision binary64 (if (<= k 1.0) (* (/ (* (sqrt PI) (sqrt n)) (sqrt k)) (sqrt 2.0)) (* (/ 1.0 (sqrt k)) (pow (* (+ PI PI) n) (* -0.5 k)))))
double code(double k, double n) {
double tmp;
if (k <= 1.0) {
tmp = ((sqrt(((double) M_PI)) * sqrt(n)) / sqrt(k)) * sqrt(2.0);
} else {
tmp = (1.0 / sqrt(k)) * pow(((((double) M_PI) + ((double) M_PI)) * n), (-0.5 * k));
}
return tmp;
}
public static double code(double k, double n) {
double tmp;
if (k <= 1.0) {
tmp = ((Math.sqrt(Math.PI) * Math.sqrt(n)) / Math.sqrt(k)) * Math.sqrt(2.0);
} else {
tmp = (1.0 / Math.sqrt(k)) * Math.pow(((Math.PI + Math.PI) * n), (-0.5 * k));
}
return tmp;
}
def code(k, n): tmp = 0 if k <= 1.0: tmp = ((math.sqrt(math.pi) * math.sqrt(n)) / math.sqrt(k)) * math.sqrt(2.0) else: tmp = (1.0 / math.sqrt(k)) * math.pow(((math.pi + math.pi) * n), (-0.5 * k)) return tmp
function code(k, n) tmp = 0.0 if (k <= 1.0) tmp = Float64(Float64(Float64(sqrt(pi) * sqrt(n)) / sqrt(k)) * sqrt(2.0)); else tmp = Float64(Float64(1.0 / sqrt(k)) * (Float64(Float64(pi + pi) * n) ^ Float64(-0.5 * k))); end return tmp end
function tmp_2 = code(k, n) tmp = 0.0; if (k <= 1.0) tmp = ((sqrt(pi) * sqrt(n)) / sqrt(k)) * sqrt(2.0); else tmp = (1.0 / sqrt(k)) * (((pi + pi) * n) ^ (-0.5 * k)); end tmp_2 = tmp; end
code[k_, n_] := If[LessEqual[k, 1.0], N[(N[(N[(N[Sqrt[Pi], $MachinePrecision] * N[Sqrt[n], $MachinePrecision]), $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision] * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / N[Sqrt[k], $MachinePrecision]), $MachinePrecision] * N[Power[N[(N[(Pi + Pi), $MachinePrecision] * n), $MachinePrecision], N[(-0.5 * k), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;k \leq 1:\\
\;\;\;\;\frac{\sqrt{\pi} \cdot \sqrt{n}}{\sqrt{k}} \cdot \sqrt{2}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{\sqrt{k}} \cdot {\left(\left(\pi + \pi\right) \cdot n\right)}^{\left(-0.5 \cdot k\right)}\\
\end{array}
\end{array}
if k < 1Initial program 98.4%
Taylor expanded in k around 0
sqrt-unprodN/A
lower-sqrt.f64N/A
lower-*.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
lift-PI.f6476.2
Applied rewrites76.2%
lift-sqrt.f64N/A
lift-*.f64N/A
sqrt-prodN/A
lift-/.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-sqrt.f64N/A
lower-/.f64N/A
*-commutativeN/A
lift-*.f64N/A
lift-PI.f64N/A
lift-sqrt.f6475.8
Applied rewrites75.8%
lift-sqrt.f64N/A
lift-/.f64N/A
sqrt-divN/A
lift-PI.f64N/A
lift-*.f64N/A
*-commutativeN/A
lower-/.f64N/A
lower-sqrt.f64N/A
*-commutativeN/A
lift-*.f64N/A
lift-PI.f64N/A
lift-sqrt.f6498.1
Applied rewrites98.1%
lift-sqrt.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
sqrt-prodN/A
lower-*.f64N/A
lower-sqrt.f64N/A
lift-PI.f64N/A
lower-sqrt.f6498.1
Applied rewrites98.1%
if 1 < k Initial program 100.0%
Taylor expanded in k around 0
+-commutativeN/A
lower-fma.f64100.0
Applied rewrites100.0%
lift-PI.f64N/A
lift-*.f64N/A
count-2-revN/A
lift-+.f64N/A
lift-PI.f64N/A
lift-PI.f64100.0
Applied rewrites100.0%
Taylor expanded in k around inf
lower-*.f6499.3
Applied rewrites99.3%
(FPCore (k n) :precision binary64 (* (/ 1.0 (sqrt k)) (pow (* (+ PI PI) n) (fma -0.5 k 0.5))))
double code(double k, double n) {
return (1.0 / sqrt(k)) * pow(((((double) M_PI) + ((double) M_PI)) * n), fma(-0.5, k, 0.5));
}
function code(k, n) return Float64(Float64(1.0 / sqrt(k)) * (Float64(Float64(pi + pi) * n) ^ fma(-0.5, k, 0.5))) end
code[k_, n_] := N[(N[(1.0 / N[Sqrt[k], $MachinePrecision]), $MachinePrecision] * N[Power[N[(N[(Pi + Pi), $MachinePrecision] * n), $MachinePrecision], N[(-0.5 * k + 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\sqrt{k}} \cdot {\left(\left(\pi + \pi\right) \cdot n\right)}^{\left(\mathsf{fma}\left(-0.5, k, 0.5\right)\right)}
\end{array}
Initial program 99.2%
Taylor expanded in k around 0
+-commutativeN/A
lower-fma.f6499.2
Applied rewrites99.2%
lift-PI.f64N/A
lift-*.f64N/A
count-2-revN/A
lift-+.f64N/A
lift-PI.f64N/A
lift-PI.f6499.2
Applied rewrites99.2%
(FPCore (k n) :precision binary64 (* (/ (* (sqrt PI) (sqrt n)) (sqrt k)) (sqrt 2.0)))
double code(double k, double n) {
return ((sqrt(((double) M_PI)) * sqrt(n)) / sqrt(k)) * sqrt(2.0);
}
public static double code(double k, double n) {
return ((Math.sqrt(Math.PI) * Math.sqrt(n)) / Math.sqrt(k)) * Math.sqrt(2.0);
}
def code(k, n): return ((math.sqrt(math.pi) * math.sqrt(n)) / math.sqrt(k)) * math.sqrt(2.0)
function code(k, n) return Float64(Float64(Float64(sqrt(pi) * sqrt(n)) / sqrt(k)) * sqrt(2.0)) end
function tmp = code(k, n) tmp = ((sqrt(pi) * sqrt(n)) / sqrt(k)) * sqrt(2.0); end
code[k_, n_] := N[(N[(N[(N[Sqrt[Pi], $MachinePrecision] * N[Sqrt[n], $MachinePrecision]), $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision] * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\sqrt{\pi} \cdot \sqrt{n}}{\sqrt{k}} \cdot \sqrt{2}
\end{array}
Initial program 99.2%
Taylor expanded in k around 0
sqrt-unprodN/A
lower-sqrt.f64N/A
lower-*.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
lift-PI.f6440.0
Applied rewrites40.0%
lift-sqrt.f64N/A
lift-*.f64N/A
sqrt-prodN/A
lift-/.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-sqrt.f64N/A
lower-/.f64N/A
*-commutativeN/A
lift-*.f64N/A
lift-PI.f64N/A
lift-sqrt.f6439.8
Applied rewrites39.8%
lift-sqrt.f64N/A
lift-/.f64N/A
sqrt-divN/A
lift-PI.f64N/A
lift-*.f64N/A
*-commutativeN/A
lower-/.f64N/A
lower-sqrt.f64N/A
*-commutativeN/A
lift-*.f64N/A
lift-PI.f64N/A
lift-sqrt.f6451.1
Applied rewrites51.1%
lift-sqrt.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
sqrt-prodN/A
lower-*.f64N/A
lower-sqrt.f64N/A
lift-PI.f64N/A
lower-sqrt.f6451.2
Applied rewrites51.2%
(FPCore (k n) :precision binary64 (* (/ (sqrt (* PI n)) (sqrt k)) (sqrt 2.0)))
double code(double k, double n) {
return (sqrt((((double) M_PI) * n)) / sqrt(k)) * sqrt(2.0);
}
public static double code(double k, double n) {
return (Math.sqrt((Math.PI * n)) / Math.sqrt(k)) * Math.sqrt(2.0);
}
def code(k, n): return (math.sqrt((math.pi * n)) / math.sqrt(k)) * math.sqrt(2.0)
function code(k, n) return Float64(Float64(sqrt(Float64(pi * n)) / sqrt(k)) * sqrt(2.0)) end
function tmp = code(k, n) tmp = (sqrt((pi * n)) / sqrt(k)) * sqrt(2.0); end
code[k_, n_] := N[(N[(N[Sqrt[N[(Pi * n), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision] * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\sqrt{\pi \cdot n}}{\sqrt{k}} \cdot \sqrt{2}
\end{array}
Initial program 99.2%
Taylor expanded in k around 0
sqrt-unprodN/A
lower-sqrt.f64N/A
lower-*.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
lift-PI.f6440.0
Applied rewrites40.0%
lift-sqrt.f64N/A
lift-*.f64N/A
sqrt-prodN/A
lift-/.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
*-commutativeN/A
lower-*.f64N/A
lower-sqrt.f64N/A
lower-/.f64N/A
*-commutativeN/A
lift-*.f64N/A
lift-PI.f64N/A
lift-sqrt.f6439.8
Applied rewrites39.8%
lift-sqrt.f64N/A
lift-/.f64N/A
sqrt-divN/A
lift-PI.f64N/A
lift-*.f64N/A
*-commutativeN/A
lower-/.f64N/A
lower-sqrt.f64N/A
*-commutativeN/A
lift-*.f64N/A
lift-PI.f64N/A
lift-sqrt.f6451.1
Applied rewrites51.1%
(FPCore (k n) :precision binary64 (/ (sqrt (* n (* PI 2.0))) (sqrt k)))
double code(double k, double n) {
return sqrt((n * (((double) M_PI) * 2.0))) / sqrt(k);
}
public static double code(double k, double n) {
return Math.sqrt((n * (Math.PI * 2.0))) / Math.sqrt(k);
}
def code(k, n): return math.sqrt((n * (math.pi * 2.0))) / math.sqrt(k)
function code(k, n) return Float64(sqrt(Float64(n * Float64(pi * 2.0))) / sqrt(k)) end
function tmp = code(k, n) tmp = sqrt((n * (pi * 2.0))) / sqrt(k); end
code[k_, n_] := N[(N[Sqrt[N[(n * N[(Pi * 2.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\sqrt{n \cdot \left(\pi \cdot 2\right)}}{\sqrt{k}}
\end{array}
Initial program 99.2%
lift-*.f64N/A
lift-/.f64N/A
lift-sqrt.f64N/A
lift-pow.f64N/A
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
lift--.f64N/A
lift-/.f64N/A
associate-*l/N/A
lower-/.f64N/A
Applied rewrites99.3%
Taylor expanded in k around 0
*-lft-identityN/A
*-commutativeN/A
sqrt-unprodN/A
*-commutativeN/A
*-commutativeN/A
associate-*l*N/A
*-commutativeN/A
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
lift-sqrt.f6450.9
lift-*.f64N/A
*-commutativeN/A
lower-*.f6450.9
Applied rewrites50.9%
(FPCore (k n) :precision binary64 (sqrt (* PI (* (/ n k) 2.0))))
double code(double k, double n) {
return sqrt((((double) M_PI) * ((n / k) * 2.0)));
}
public static double code(double k, double n) {
return Math.sqrt((Math.PI * ((n / k) * 2.0)));
}
def code(k, n): return math.sqrt((math.pi * ((n / k) * 2.0)))
function code(k, n) return sqrt(Float64(pi * Float64(Float64(n / k) * 2.0))) end
function tmp = code(k, n) tmp = sqrt((pi * ((n / k) * 2.0))); end
code[k_, n_] := N[Sqrt[N[(Pi * N[(N[(n / k), $MachinePrecision] * 2.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\pi \cdot \left(\frac{n}{k} \cdot 2\right)}
\end{array}
Initial program 99.2%
Taylor expanded in k around 0
sqrt-unprodN/A
lower-sqrt.f64N/A
lower-*.f64N/A
lower-/.f64N/A
*-commutativeN/A
lower-*.f64N/A
lift-PI.f6440.0
Applied rewrites40.0%
lift-/.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
associate-/l*N/A
lower-*.f64N/A
lift-PI.f64N/A
lower-/.f6440.0
Applied rewrites40.0%
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
associate-*l*N/A
lower-*.f64N/A
lift-PI.f64N/A
lower-*.f6440.0
Applied rewrites40.0%
herbie shell --seed 2025061
(FPCore (k n)
:name "Migdal et al, Equation (51)"
:precision binary64
(* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0))))