
(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 (if (<= k 1.55e-50) (* (pow k -0.5) (sqrt (* n (* 2.0 PI)))) (/ 1.0 (sqrt (/ k (pow (* PI (* 2.0 n)) (- 1.0 k)))))))
double code(double k, double n) {
double tmp;
if (k <= 1.55e-50) {
tmp = pow(k, -0.5) * sqrt((n * (2.0 * ((double) M_PI))));
} else {
tmp = 1.0 / sqrt((k / pow((((double) M_PI) * (2.0 * n)), (1.0 - k))));
}
return tmp;
}
public static double code(double k, double n) {
double tmp;
if (k <= 1.55e-50) {
tmp = Math.pow(k, -0.5) * Math.sqrt((n * (2.0 * Math.PI)));
} else {
tmp = 1.0 / Math.sqrt((k / Math.pow((Math.PI * (2.0 * n)), (1.0 - k))));
}
return tmp;
}
def code(k, n): tmp = 0 if k <= 1.55e-50: tmp = math.pow(k, -0.5) * math.sqrt((n * (2.0 * math.pi))) else: tmp = 1.0 / math.sqrt((k / math.pow((math.pi * (2.0 * n)), (1.0 - k)))) return tmp
function code(k, n) tmp = 0.0 if (k <= 1.55e-50) tmp = Float64((k ^ -0.5) * sqrt(Float64(n * Float64(2.0 * pi)))); else tmp = Float64(1.0 / sqrt(Float64(k / (Float64(pi * Float64(2.0 * n)) ^ Float64(1.0 - k))))); end return tmp end
function tmp_2 = code(k, n) tmp = 0.0; if (k <= 1.55e-50) tmp = (k ^ -0.5) * sqrt((n * (2.0 * pi))); else tmp = 1.0 / sqrt((k / ((pi * (2.0 * n)) ^ (1.0 - k)))); end tmp_2 = tmp; end
code[k_, n_] := If[LessEqual[k, 1.55e-50], N[(N[Power[k, -0.5], $MachinePrecision] * N[Sqrt[N[(n * N[(2.0 * Pi), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(1.0 / N[Sqrt[N[(k / N[Power[N[(Pi * N[(2.0 * n), $MachinePrecision]), $MachinePrecision], N[(1.0 - k), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;k \leq 1.55 \cdot 10^{-50}:\\
\;\;\;\;{k}^{-0.5} \cdot \sqrt{n \cdot \left(2 \cdot \pi\right)}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{\sqrt{\frac{k}{{\left(\pi \cdot \left(2 \cdot n\right)\right)}^{\left(1 - k\right)}}}}\\
\end{array}
\end{array}
if k < 1.5500000000000001e-50Initial program 99.5%
Taylor expanded in k around 0 99.1%
associate-*l/99.2%
*-un-lft-identity99.2%
sqrt-unprod99.5%
*-commutative99.5%
*-commutative99.5%
Applied egg-rr99.5%
*-commutative99.5%
associate-*r*99.5%
Simplified99.5%
div-inv99.5%
associate-*r*99.5%
*-commutative99.5%
pow1/299.5%
pow-flip99.5%
metadata-eval99.5%
Applied egg-rr99.5%
*-commutative99.5%
associate-*r*99.5%
*-commutative99.5%
Simplified99.5%
if 1.5500000000000001e-50 < k Initial program 99.8%
add-sqr-sqrt99.8%
sqrt-unprod99.8%
*-commutative99.8%
div-inv99.8%
*-commutative99.8%
div-inv99.8%
frac-times99.8%
Applied egg-rr99.8%
Simplified99.8%
clear-num99.8%
sqrt-div99.8%
metadata-eval99.8%
Applied egg-rr99.8%
*-commutative99.8%
Simplified99.8%
Final simplification99.7%
(FPCore (k n) :precision binary64 (* (pow (* 2.0 (* PI n)) (- 0.5 (* 0.5 k))) (pow k -0.5)))
double code(double k, double n) {
return pow((2.0 * (((double) M_PI) * n)), (0.5 - (0.5 * k))) * pow(k, -0.5);
}
public static double code(double k, double n) {
return Math.pow((2.0 * (Math.PI * n)), (0.5 - (0.5 * k))) * Math.pow(k, -0.5);
}
def code(k, n): return math.pow((2.0 * (math.pi * n)), (0.5 - (0.5 * k))) * math.pow(k, -0.5)
function code(k, n) return Float64((Float64(2.0 * Float64(pi * n)) ^ Float64(0.5 - Float64(0.5 * k))) * (k ^ -0.5)) end
function tmp = code(k, n) tmp = ((2.0 * (pi * n)) ^ (0.5 - (0.5 * k))) * (k ^ -0.5); end
code[k_, n_] := N[(N[Power[N[(2.0 * N[(Pi * n), $MachinePrecision]), $MachinePrecision], N[(0.5 - N[(0.5 * k), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[Power[k, -0.5], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
{\left(2 \cdot \left(\pi \cdot n\right)\right)}^{\left(0.5 - 0.5 \cdot k\right)} \cdot {k}^{-0.5}
\end{array}
Initial program 99.7%
associate-*l/99.7%
*-lft-identity99.7%
sqr-pow99.5%
pow-sqr99.7%
associate-*l*99.7%
*-commutative99.7%
associate-*l/99.7%
associate-/l*99.7%
metadata-eval99.7%
/-rgt-identity99.7%
div-sub99.7%
metadata-eval99.7%
Simplified99.7%
div-inv99.7%
div-inv99.7%
metadata-eval99.7%
pow1/299.7%
pow-flip99.7%
metadata-eval99.7%
Applied egg-rr99.7%
Final simplification99.7%
(FPCore (k n) :precision binary64 (if (<= k 1.35e-50) (* (pow k -0.5) (sqrt (* n (* 2.0 PI)))) (sqrt (/ (pow (* PI (* 2.0 n)) (- 1.0 k)) k))))
double code(double k, double n) {
double tmp;
if (k <= 1.35e-50) {
tmp = pow(k, -0.5) * sqrt((n * (2.0 * ((double) M_PI))));
} else {
tmp = sqrt((pow((((double) M_PI) * (2.0 * n)), (1.0 - k)) / k));
}
return tmp;
}
public static double code(double k, double n) {
double tmp;
if (k <= 1.35e-50) {
tmp = Math.pow(k, -0.5) * Math.sqrt((n * (2.0 * Math.PI)));
} else {
tmp = Math.sqrt((Math.pow((Math.PI * (2.0 * n)), (1.0 - k)) / k));
}
return tmp;
}
def code(k, n): tmp = 0 if k <= 1.35e-50: tmp = math.pow(k, -0.5) * math.sqrt((n * (2.0 * math.pi))) else: tmp = math.sqrt((math.pow((math.pi * (2.0 * n)), (1.0 - k)) / k)) return tmp
function code(k, n) tmp = 0.0 if (k <= 1.35e-50) tmp = Float64((k ^ -0.5) * sqrt(Float64(n * Float64(2.0 * pi)))); else tmp = sqrt(Float64((Float64(pi * Float64(2.0 * n)) ^ Float64(1.0 - k)) / k)); end return tmp end
function tmp_2 = code(k, n) tmp = 0.0; if (k <= 1.35e-50) tmp = (k ^ -0.5) * sqrt((n * (2.0 * pi))); else tmp = sqrt((((pi * (2.0 * n)) ^ (1.0 - k)) / k)); end tmp_2 = tmp; end
code[k_, n_] := If[LessEqual[k, 1.35e-50], N[(N[Power[k, -0.5], $MachinePrecision] * N[Sqrt[N[(n * N[(2.0 * Pi), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[Sqrt[N[(N[Power[N[(Pi * N[(2.0 * n), $MachinePrecision]), $MachinePrecision], N[(1.0 - k), $MachinePrecision]], $MachinePrecision] / k), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;k \leq 1.35 \cdot 10^{-50}:\\
\;\;\;\;{k}^{-0.5} \cdot \sqrt{n \cdot \left(2 \cdot \pi\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\frac{{\left(\pi \cdot \left(2 \cdot n\right)\right)}^{\left(1 - k\right)}}{k}}\\
\end{array}
\end{array}
if k < 1.35e-50Initial program 99.5%
Taylor expanded in k around 0 99.1%
associate-*l/99.2%
*-un-lft-identity99.2%
sqrt-unprod99.5%
*-commutative99.5%
*-commutative99.5%
Applied egg-rr99.5%
*-commutative99.5%
associate-*r*99.5%
Simplified99.5%
div-inv99.5%
associate-*r*99.5%
*-commutative99.5%
pow1/299.5%
pow-flip99.5%
metadata-eval99.5%
Applied egg-rr99.5%
*-commutative99.5%
associate-*r*99.5%
*-commutative99.5%
Simplified99.5%
if 1.35e-50 < k Initial program 99.8%
add-sqr-sqrt99.8%
sqrt-unprod99.8%
*-commutative99.8%
div-inv99.8%
*-commutative99.8%
div-inv99.8%
frac-times99.8%
Applied egg-rr99.8%
Simplified99.8%
Final simplification99.7%
(FPCore (k n) :precision binary64 (/ (pow (* 2.0 (* PI n)) (- 0.5 (/ k 2.0))) (sqrt k)))
double code(double k, double n) {
return pow((2.0 * (((double) M_PI) * n)), (0.5 - (k / 2.0))) / sqrt(k);
}
public static double code(double k, double n) {
return Math.pow((2.0 * (Math.PI * n)), (0.5 - (k / 2.0))) / Math.sqrt(k);
}
def code(k, n): return math.pow((2.0 * (math.pi * n)), (0.5 - (k / 2.0))) / math.sqrt(k)
function code(k, n) return Float64((Float64(2.0 * Float64(pi * n)) ^ Float64(0.5 - Float64(k / 2.0))) / sqrt(k)) end
function tmp = code(k, n) tmp = ((2.0 * (pi * n)) ^ (0.5 - (k / 2.0))) / sqrt(k); end
code[k_, n_] := N[(N[Power[N[(2.0 * N[(Pi * n), $MachinePrecision]), $MachinePrecision], N[(0.5 - N[(k / 2.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{{\left(2 \cdot \left(\pi \cdot n\right)\right)}^{\left(0.5 - \frac{k}{2}\right)}}{\sqrt{k}}
\end{array}
Initial program 99.7%
associate-*l/99.7%
*-lft-identity99.7%
sqr-pow99.5%
pow-sqr99.7%
associate-*l*99.7%
*-commutative99.7%
associate-*l/99.7%
associate-/l*99.7%
metadata-eval99.7%
/-rgt-identity99.7%
div-sub99.7%
metadata-eval99.7%
Simplified99.7%
Final simplification99.7%
(FPCore (k n) :precision binary64 (* (pow k -0.5) (sqrt (* n (* 2.0 PI)))))
double code(double k, double n) {
return pow(k, -0.5) * sqrt((n * (2.0 * ((double) M_PI))));
}
public static double code(double k, double n) {
return Math.pow(k, -0.5) * Math.sqrt((n * (2.0 * Math.PI)));
}
def code(k, n): return math.pow(k, -0.5) * math.sqrt((n * (2.0 * math.pi)))
function code(k, n) return Float64((k ^ -0.5) * sqrt(Float64(n * Float64(2.0 * pi)))) end
function tmp = code(k, n) tmp = (k ^ -0.5) * sqrt((n * (2.0 * pi))); end
code[k_, n_] := N[(N[Power[k, -0.5], $MachinePrecision] * N[Sqrt[N[(n * N[(2.0 * Pi), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
{k}^{-0.5} \cdot \sqrt{n \cdot \left(2 \cdot \pi\right)}
\end{array}
Initial program 99.7%
Taylor expanded in k around 0 51.1%
associate-*l/51.1%
*-un-lft-identity51.1%
sqrt-unprod51.2%
*-commutative51.2%
*-commutative51.2%
Applied egg-rr51.2%
*-commutative51.2%
associate-*r*51.2%
Simplified51.2%
div-inv51.2%
associate-*r*51.2%
*-commutative51.2%
pow1/251.2%
pow-flip51.3%
metadata-eval51.3%
Applied egg-rr51.3%
*-commutative51.3%
associate-*r*51.3%
*-commutative51.3%
Simplified51.3%
Final simplification51.3%
(FPCore (k n) :precision binary64 (* (sqrt (* 2.0 n)) (sqrt (/ PI k))))
double code(double k, double n) {
return sqrt((2.0 * n)) * sqrt((((double) M_PI) / k));
}
public static double code(double k, double n) {
return Math.sqrt((2.0 * n)) * Math.sqrt((Math.PI / k));
}
def code(k, n): return math.sqrt((2.0 * n)) * math.sqrt((math.pi / k))
function code(k, n) return Float64(sqrt(Float64(2.0 * n)) * sqrt(Float64(pi / k))) end
function tmp = code(k, n) tmp = sqrt((2.0 * n)) * sqrt((pi / k)); end
code[k_, n_] := N[(N[Sqrt[N[(2.0 * n), $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[(Pi / k), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\sqrt{2 \cdot n} \cdot \sqrt{\frac{\pi}{k}}
\end{array}
Initial program 99.7%
add-sqr-sqrt99.4%
sqrt-unprod90.1%
*-commutative90.1%
div-inv90.2%
*-commutative90.2%
div-inv90.1%
frac-times90.1%
Applied egg-rr90.2%
Simplified90.2%
Taylor expanded in k around 0 41.7%
associate-/l*41.7%
Simplified41.7%
associate-/r/41.7%
Applied egg-rr41.7%
*-commutative41.7%
clear-num41.7%
div-inv41.7%
associate-/r/41.7%
add-sqr-sqrt41.7%
sqrt-unprod36.3%
sqr-neg36.3%
sqrt-unprod0.0%
add-sqr-sqrt0.2%
clear-num0.2%
add-sqr-sqrt0.2%
sqrt-unprod0.8%
sqr-neg0.8%
sqrt-unprod0.0%
add-sqr-sqrt41.7%
*-commutative41.7%
associate-*r*41.7%
sqrt-prod0.0%
Applied egg-rr51.2%
Final simplification51.2%
(FPCore (k n) :precision binary64 (/ 1.0 (sqrt (/ (/ k 2.0) (* PI n)))))
double code(double k, double n) {
return 1.0 / sqrt(((k / 2.0) / (((double) M_PI) * n)));
}
public static double code(double k, double n) {
return 1.0 / Math.sqrt(((k / 2.0) / (Math.PI * n)));
}
def code(k, n): return 1.0 / math.sqrt(((k / 2.0) / (math.pi * n)))
function code(k, n) return Float64(1.0 / sqrt(Float64(Float64(k / 2.0) / Float64(pi * n)))) end
function tmp = code(k, n) tmp = 1.0 / sqrt(((k / 2.0) / (pi * n))); end
code[k_, n_] := N[(1.0 / N[Sqrt[N[(N[(k / 2.0), $MachinePrecision] / N[(Pi * n), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\sqrt{\frac{\frac{k}{2}}{\pi \cdot n}}}
\end{array}
Initial program 99.7%
Taylor expanded in k around 0 51.1%
associate-*l/51.1%
*-un-lft-identity51.1%
sqrt-unprod51.2%
*-commutative51.2%
*-commutative51.2%
Applied egg-rr51.2%
*-commutative51.2%
associate-*r*51.2%
Simplified51.2%
clear-num51.1%
inv-pow51.1%
sqrt-undiv41.9%
associate-*r*41.9%
*-commutative41.9%
Applied egg-rr41.9%
unpow-141.9%
associate-/r*41.9%
*-commutative41.9%
Simplified41.9%
Final simplification41.9%
(FPCore (k n) :precision binary64 (sqrt (* 2.0 (* PI (/ n k)))))
double code(double k, double n) {
return sqrt((2.0 * (((double) M_PI) * (n / k))));
}
public static double code(double k, double n) {
return Math.sqrt((2.0 * (Math.PI * (n / k))));
}
def code(k, n): return math.sqrt((2.0 * (math.pi * (n / k))))
function code(k, n) return sqrt(Float64(2.0 * Float64(pi * Float64(n / k)))) end
function tmp = code(k, n) tmp = sqrt((2.0 * (pi * (n / k)))); end
code[k_, n_] := N[Sqrt[N[(2.0 * N[(Pi * N[(n / k), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{2 \cdot \left(\pi \cdot \frac{n}{k}\right)}
\end{array}
Initial program 99.7%
add-sqr-sqrt99.4%
sqrt-unprod90.1%
*-commutative90.1%
div-inv90.2%
*-commutative90.2%
div-inv90.1%
frac-times90.1%
Applied egg-rr90.2%
Simplified90.2%
Taylor expanded in k around 0 41.7%
associate-/l*41.7%
Simplified41.7%
associate-/r/41.7%
Applied egg-rr41.7%
Final simplification41.7%
(FPCore (k n) :precision binary64 (sqrt (* 2.0 (/ PI (/ k n)))))
double code(double k, double n) {
return sqrt((2.0 * (((double) M_PI) / (k / n))));
}
public static double code(double k, double n) {
return Math.sqrt((2.0 * (Math.PI / (k / n))));
}
def code(k, n): return math.sqrt((2.0 * (math.pi / (k / n))))
function code(k, n) return sqrt(Float64(2.0 * Float64(pi / Float64(k / n)))) end
function tmp = code(k, n) tmp = sqrt((2.0 * (pi / (k / n)))); end
code[k_, n_] := N[Sqrt[N[(2.0 * N[(Pi / N[(k / n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{2 \cdot \frac{\pi}{\frac{k}{n}}}
\end{array}
Initial program 99.7%
add-sqr-sqrt99.4%
sqrt-unprod90.1%
*-commutative90.1%
div-inv90.2%
*-commutative90.2%
div-inv90.1%
frac-times90.1%
Applied egg-rr90.2%
Simplified90.2%
Taylor expanded in k around 0 41.7%
associate-/l*41.7%
Simplified41.7%
Taylor expanded in n around 0 41.7%
*-commutative41.7%
associate-/l*41.7%
Simplified41.7%
Final simplification41.7%
herbie shell --seed 2023299
(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))))