
(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 9 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 (let* ((t_0 (* 2.0 (* PI n)))) (/ (sqrt t_0) (* (sqrt k) (pow t_0 (* k 0.5))))))
double code(double k, double n) {
double t_0 = 2.0 * (((double) M_PI) * n);
return sqrt(t_0) / (sqrt(k) * pow(t_0, (k * 0.5)));
}
public static double code(double k, double n) {
double t_0 = 2.0 * (Math.PI * n);
return Math.sqrt(t_0) / (Math.sqrt(k) * Math.pow(t_0, (k * 0.5)));
}
def code(k, n): t_0 = 2.0 * (math.pi * n) return math.sqrt(t_0) / (math.sqrt(k) * math.pow(t_0, (k * 0.5)))
function code(k, n) t_0 = Float64(2.0 * Float64(pi * n)) return Float64(sqrt(t_0) / Float64(sqrt(k) * (t_0 ^ Float64(k * 0.5)))) end
function tmp = code(k, n) t_0 = 2.0 * (pi * n); tmp = sqrt(t_0) / (sqrt(k) * (t_0 ^ (k * 0.5))); end
code[k_, n_] := Block[{t$95$0 = N[(2.0 * N[(Pi * n), $MachinePrecision]), $MachinePrecision]}, N[(N[Sqrt[t$95$0], $MachinePrecision] / N[(N[Sqrt[k], $MachinePrecision] * N[Power[t$95$0, N[(k * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 2 \cdot \left(\pi \cdot n\right)\\
\frac{\sqrt{t\_0}}{\sqrt{k} \cdot {t\_0}^{\left(k \cdot 0.5\right)}}
\end{array}
\end{array}
Initial program 99.3%
lift-*.f64N/A
*-commutativeN/A
lift-/.f64N/A
un-div-invN/A
lift-pow.f64N/A
lift-/.f64N/A
lift--.f64N/A
div-subN/A
metadata-evalN/A
pow-subN/A
associate-/l/N/A
lower-/.f64N/A
Applied rewrites99.6%
(FPCore (k n) :precision binary64 (* (sqrt (/ 1.0 k)) (pow (* n (* 2.0 PI)) (fma -0.5 k 0.5))))
double code(double k, double n) {
return sqrt((1.0 / k)) * pow((n * (2.0 * ((double) M_PI))), fma(-0.5, k, 0.5));
}
function code(k, n) return Float64(sqrt(Float64(1.0 / k)) * (Float64(n * Float64(2.0 * pi)) ^ fma(-0.5, k, 0.5))) end
code[k_, n_] := N[(N[Sqrt[N[(1.0 / k), $MachinePrecision]], $MachinePrecision] * N[Power[N[(n * N[(2.0 * Pi), $MachinePrecision]), $MachinePrecision], N[(-0.5 * k + 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\frac{1}{k}} \cdot {\left(n \cdot \left(2 \cdot \pi\right)\right)}^{\left(\mathsf{fma}\left(-0.5, k, 0.5\right)\right)}
\end{array}
Initial program 99.3%
Taylor expanded in k around inf
lower-*.f64N/A
lower-sqrt.f64N/A
lower-/.f64N/A
*-commutativeN/A
associate-*l*N/A
exp-prodN/A
*-commutativeN/A
lower-pow.f64N/A
rem-exp-logN/A
associate-*r*N/A
*-commutativeN/A
associate-*r*N/A
rem-exp-logN/A
lower-*.f64N/A
rem-exp-logN/A
*-commutativeN/A
lower-*.f64N/A
lower-PI.f64N/A
sub-negN/A
mul-1-negN/A
Applied rewrites99.4%
Final simplification99.4%
(FPCore (k n) :precision binary64 (/ (pow (* 2.0 (* PI n)) (fma k -0.5 0.5)) (sqrt k)))
double code(double k, double n) {
return pow((2.0 * (((double) M_PI) * n)), fma(k, -0.5, 0.5)) / sqrt(k);
}
function code(k, n) return Float64((Float64(2.0 * Float64(pi * n)) ^ fma(k, -0.5, 0.5)) / sqrt(k)) end
code[k_, n_] := N[(N[Power[N[(2.0 * N[(Pi * n), $MachinePrecision]), $MachinePrecision], N[(k * -0.5 + 0.5), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{{\left(2 \cdot \left(\pi \cdot n\right)\right)}^{\left(\mathsf{fma}\left(k, -0.5, 0.5\right)\right)}}{\sqrt{k}}
\end{array}
Initial program 99.3%
lift-*.f64N/A
*-commutativeN/A
lift-/.f64N/A
un-div-invN/A
lift-pow.f64N/A
lift-/.f64N/A
lift--.f64N/A
div-subN/A
metadata-evalN/A
pow-subN/A
associate-/l/N/A
lower-/.f64N/A
Applied rewrites99.6%
lift-/.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-/r*N/A
Applied rewrites99.4%
(FPCore (k n) :precision binary64 (* (* (sqrt (sqrt PI)) (sqrt (/ (sqrt PI) k))) (sqrt (* 2.0 n))))
double code(double k, double n) {
return (sqrt(sqrt(((double) M_PI))) * sqrt((sqrt(((double) M_PI)) / k))) * sqrt((2.0 * n));
}
public static double code(double k, double n) {
return (Math.sqrt(Math.sqrt(Math.PI)) * Math.sqrt((Math.sqrt(Math.PI) / k))) * Math.sqrt((2.0 * n));
}
def code(k, n): return (math.sqrt(math.sqrt(math.pi)) * math.sqrt((math.sqrt(math.pi) / k))) * math.sqrt((2.0 * n))
function code(k, n) return Float64(Float64(sqrt(sqrt(pi)) * sqrt(Float64(sqrt(pi) / k))) * sqrt(Float64(2.0 * n))) end
function tmp = code(k, n) tmp = (sqrt(sqrt(pi)) * sqrt((sqrt(pi) / k))) * sqrt((2.0 * n)); end
code[k_, n_] := N[(N[(N[Sqrt[N[Sqrt[Pi], $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[(N[Sqrt[Pi], $MachinePrecision] / k), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[(2.0 * n), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\left(\sqrt{\sqrt{\pi}} \cdot \sqrt{\frac{\sqrt{\pi}}{k}}\right) \cdot \sqrt{2 \cdot n}
\end{array}
Initial program 99.3%
Taylor expanded in k around 0
lower-*.f64N/A
lower-sqrt.f64N/A
lower-/.f64N/A
lower-*.f64N/A
lower-PI.f64N/A
lower-sqrt.f6438.8
Applied rewrites38.8%
Applied rewrites38.6%
Applied rewrites38.6%
Applied rewrites51.1%
Final simplification51.1%
(FPCore (k n) :precision binary64 (* (sqrt (/ PI k)) (sqrt (* 2.0 n))))
double code(double k, double n) {
return sqrt((((double) M_PI) / k)) * sqrt((2.0 * n));
}
public static double code(double k, double n) {
return Math.sqrt((Math.PI / k)) * Math.sqrt((2.0 * n));
}
def code(k, n): return math.sqrt((math.pi / k)) * math.sqrt((2.0 * n))
function code(k, n) return Float64(sqrt(Float64(pi / k)) * sqrt(Float64(2.0 * n))) end
function tmp = code(k, n) tmp = sqrt((pi / k)) * sqrt((2.0 * n)); end
code[k_, n_] := N[(N[Sqrt[N[(Pi / k), $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[(2.0 * n), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\frac{\pi}{k}} \cdot \sqrt{2 \cdot n}
\end{array}
Initial program 99.3%
Taylor expanded in k around 0
lower-*.f64N/A
lower-sqrt.f64N/A
lower-/.f64N/A
lower-*.f64N/A
lower-PI.f64N/A
lower-sqrt.f6438.8
Applied rewrites38.8%
Applied rewrites38.6%
Applied rewrites51.0%
Final simplification51.0%
(FPCore (k n) :precision binary64 (* (sqrt n) (sqrt (* 2.0 (/ PI k)))))
double code(double k, double n) {
return sqrt(n) * sqrt((2.0 * (((double) M_PI) / k)));
}
public static double code(double k, double n) {
return Math.sqrt(n) * Math.sqrt((2.0 * (Math.PI / k)));
}
def code(k, n): return math.sqrt(n) * math.sqrt((2.0 * (math.pi / k)))
function code(k, n) return Float64(sqrt(n) * sqrt(Float64(2.0 * Float64(pi / k)))) end
function tmp = code(k, n) tmp = sqrt(n) * sqrt((2.0 * (pi / k))); end
code[k_, n_] := N[(N[Sqrt[n], $MachinePrecision] * N[Sqrt[N[(2.0 * N[(Pi / k), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\sqrt{n} \cdot \sqrt{2 \cdot \frac{\pi}{k}}
\end{array}
Initial program 99.3%
Taylor expanded in k around 0
lower-*.f64N/A
lower-sqrt.f64N/A
lower-/.f64N/A
lower-*.f64N/A
lower-PI.f64N/A
lower-sqrt.f6438.8
Applied rewrites38.8%
Applied rewrites51.0%
Final simplification51.0%
(FPCore (k n) :precision binary64 (sqrt (* (* PI n) (/ 2.0 k))))
double code(double k, double n) {
return sqrt(((((double) M_PI) * n) * (2.0 / k)));
}
public static double code(double k, double n) {
return Math.sqrt(((Math.PI * n) * (2.0 / k)));
}
def code(k, n): return math.sqrt(((math.pi * n) * (2.0 / k)))
function code(k, n) return sqrt(Float64(Float64(pi * n) * Float64(2.0 / k))) end
function tmp = code(k, n) tmp = sqrt(((pi * n) * (2.0 / k))); end
code[k_, n_] := N[Sqrt[N[(N[(Pi * n), $MachinePrecision] * N[(2.0 / k), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\left(\pi \cdot n\right) \cdot \frac{2}{k}}
\end{array}
Initial program 99.3%
Taylor expanded in k around 0
lower-*.f64N/A
lower-sqrt.f64N/A
lower-/.f64N/A
lower-*.f64N/A
lower-PI.f64N/A
lower-sqrt.f6438.8
Applied rewrites38.8%
Applied rewrites38.6%
Applied rewrites38.6%
(FPCore (k n) :precision binary64 (sqrt (* PI (* n (/ 2.0 k)))))
double code(double k, double n) {
return sqrt((((double) M_PI) * (n * (2.0 / k))));
}
public static double code(double k, double n) {
return Math.sqrt((Math.PI * (n * (2.0 / k))));
}
def code(k, n): return math.sqrt((math.pi * (n * (2.0 / k))))
function code(k, n) return sqrt(Float64(pi * Float64(n * Float64(2.0 / k)))) end
function tmp = code(k, n) tmp = sqrt((pi * (n * (2.0 / k)))); end
code[k_, n_] := N[Sqrt[N[(Pi * N[(n * N[(2.0 / k), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{\pi \cdot \left(n \cdot \frac{2}{k}\right)}
\end{array}
Initial program 99.3%
Taylor expanded in k around 0
lower-*.f64N/A
lower-sqrt.f64N/A
lower-/.f64N/A
lower-*.f64N/A
lower-PI.f64N/A
lower-sqrt.f6438.8
Applied rewrites38.8%
Applied rewrites38.6%
Applied rewrites38.6%
Final simplification38.6%
(FPCore (k n) :precision binary64 (sqrt (* n (* PI (/ 2.0 k)))))
double code(double k, double n) {
return sqrt((n * (((double) M_PI) * (2.0 / k))));
}
public static double code(double k, double n) {
return Math.sqrt((n * (Math.PI * (2.0 / k))));
}
def code(k, n): return math.sqrt((n * (math.pi * (2.0 / k))))
function code(k, n) return sqrt(Float64(n * Float64(pi * Float64(2.0 / k)))) end
function tmp = code(k, n) tmp = sqrt((n * (pi * (2.0 / k)))); end
code[k_, n_] := N[Sqrt[N[(n * N[(Pi * N[(2.0 / k), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{n \cdot \left(\pi \cdot \frac{2}{k}\right)}
\end{array}
Initial program 99.3%
Taylor expanded in k around 0
lower-*.f64N/A
lower-sqrt.f64N/A
lower-/.f64N/A
lower-*.f64N/A
lower-PI.f64N/A
lower-sqrt.f6438.8
Applied rewrites38.8%
Applied rewrites38.6%
Applied rewrites38.6%
Final simplification38.6%
herbie shell --seed 2024222
(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))))