
(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 5 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(pi * Float64(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[(Pi * N[(2.0 * n), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 - k), $MachinePrecision] / 2.0), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{{\left(\pi \cdot \left(2 \cdot n\right)\right)}^{\left(\frac{1 - k}{2}\right)}}{\sqrt{k}}
\end{array}
Initial program 99.5%
associate-*l/99.6%
*-lft-identity99.6%
*-commutative99.6%
associate-*l*99.6%
Simplified99.6%
Final simplification99.6%
(FPCore (k n)
:precision binary64
(let* ((t_0 (* PI (* 2.0 n))))
(if (<= k 3.8e-48)
(* (pow k -0.5) (sqrt t_0))
(pow (/ k (pow t_0 (- 1.0 k))) -0.5))))
double code(double k, double n) {
double t_0 = ((double) M_PI) * (2.0 * n);
double tmp;
if (k <= 3.8e-48) {
tmp = pow(k, -0.5) * sqrt(t_0);
} else {
tmp = pow((k / pow(t_0, (1.0 - k))), -0.5);
}
return tmp;
}
public static double code(double k, double n) {
double t_0 = Math.PI * (2.0 * n);
double tmp;
if (k <= 3.8e-48) {
tmp = Math.pow(k, -0.5) * Math.sqrt(t_0);
} else {
tmp = Math.pow((k / Math.pow(t_0, (1.0 - k))), -0.5);
}
return tmp;
}
def code(k, n): t_0 = math.pi * (2.0 * n) tmp = 0 if k <= 3.8e-48: tmp = math.pow(k, -0.5) * math.sqrt(t_0) else: tmp = math.pow((k / math.pow(t_0, (1.0 - k))), -0.5) return tmp
function code(k, n) t_0 = Float64(pi * Float64(2.0 * n)) tmp = 0.0 if (k <= 3.8e-48) tmp = Float64((k ^ -0.5) * sqrt(t_0)); else tmp = Float64(k / (t_0 ^ Float64(1.0 - k))) ^ -0.5; end return tmp end
function tmp_2 = code(k, n) t_0 = pi * (2.0 * n); tmp = 0.0; if (k <= 3.8e-48) tmp = (k ^ -0.5) * sqrt(t_0); else tmp = (k / (t_0 ^ (1.0 - k))) ^ -0.5; end tmp_2 = tmp; end
code[k_, n_] := Block[{t$95$0 = N[(Pi * N[(2.0 * n), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[k, 3.8e-48], N[(N[Power[k, -0.5], $MachinePrecision] * N[Sqrt[t$95$0], $MachinePrecision]), $MachinePrecision], N[Power[N[(k / N[Power[t$95$0, N[(1.0 - k), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], -0.5], $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \pi \cdot \left(2 \cdot n\right)\\
\mathbf{if}\;k \leq 3.8 \cdot 10^{-48}:\\
\;\;\;\;{k}^{-0.5} \cdot \sqrt{t_0}\\
\mathbf{else}:\\
\;\;\;\;{\left(\frac{k}{{t_0}^{\left(1 - k\right)}}\right)}^{-0.5}\\
\end{array}
\end{array}
if k < 3.80000000000000002e-48Initial program 99.2%
expm1-log1p-u92.0%
expm1-udef92.0%
pow1/292.0%
pow-flip92.0%
metadata-eval92.0%
Applied egg-rr92.0%
expm1-def92.0%
expm1-log1p99.3%
Simplified99.3%
Taylor expanded in k around 0 99.2%
pow199.2%
sqrt-unprod99.3%
*-commutative99.3%
Applied egg-rr99.3%
unpow199.3%
*-commutative99.3%
associate-*r*99.3%
Simplified99.3%
if 3.80000000000000002e-48 < k Initial program 99.7%
expm1-log1p-u99.3%
expm1-udef53.3%
pow1/253.3%
pow-flip53.3%
metadata-eval53.3%
Applied egg-rr53.3%
expm1-def99.3%
expm1-log1p99.7%
Simplified99.7%
*-commutative99.7%
associate-*r*99.7%
*-commutative99.7%
associate-*r*99.7%
sqrt-pow199.1%
add-sqr-sqrt99.0%
sqrt-unprod99.1%
sqrt-prod99.1%
pow-prod-up99.1%
metadata-eval99.1%
inv-pow99.1%
div-inv99.1%
clear-num99.1%
sqrt-div99.1%
metadata-eval99.1%
Applied egg-rr99.1%
expm1-log1p-u98.8%
expm1-udef93.3%
pow1/293.3%
pow-flip93.3%
associate-*r*93.3%
*-commutative93.3%
associate-*l*93.3%
metadata-eval93.3%
Applied egg-rr93.3%
expm1-def98.8%
expm1-log1p99.1%
*-commutative99.1%
associate-*r*99.1%
Simplified99.1%
Final simplification99.2%
(FPCore (k n)
:precision binary64
(let* ((t_0 (* PI (* 2.0 n))))
(if (<= k 3.5e-47)
(* (pow k -0.5) (sqrt t_0))
(sqrt (/ (pow t_0 (- 1.0 k)) k)))))
double code(double k, double n) {
double t_0 = ((double) M_PI) * (2.0 * n);
double tmp;
if (k <= 3.5e-47) {
tmp = pow(k, -0.5) * sqrt(t_0);
} else {
tmp = sqrt((pow(t_0, (1.0 - k)) / k));
}
return tmp;
}
public static double code(double k, double n) {
double t_0 = Math.PI * (2.0 * n);
double tmp;
if (k <= 3.5e-47) {
tmp = Math.pow(k, -0.5) * Math.sqrt(t_0);
} else {
tmp = Math.sqrt((Math.pow(t_0, (1.0 - k)) / k));
}
return tmp;
}
def code(k, n): t_0 = math.pi * (2.0 * n) tmp = 0 if k <= 3.5e-47: tmp = math.pow(k, -0.5) * math.sqrt(t_0) else: tmp = math.sqrt((math.pow(t_0, (1.0 - k)) / k)) return tmp
function code(k, n) t_0 = Float64(pi * Float64(2.0 * n)) tmp = 0.0 if (k <= 3.5e-47) tmp = Float64((k ^ -0.5) * sqrt(t_0)); else tmp = sqrt(Float64((t_0 ^ Float64(1.0 - k)) / k)); end return tmp end
function tmp_2 = code(k, n) t_0 = pi * (2.0 * n); tmp = 0.0; if (k <= 3.5e-47) tmp = (k ^ -0.5) * sqrt(t_0); else tmp = sqrt(((t_0 ^ (1.0 - k)) / k)); end tmp_2 = tmp; end
code[k_, n_] := Block[{t$95$0 = N[(Pi * N[(2.0 * n), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[k, 3.5e-47], N[(N[Power[k, -0.5], $MachinePrecision] * N[Sqrt[t$95$0], $MachinePrecision]), $MachinePrecision], N[Sqrt[N[(N[Power[t$95$0, N[(1.0 - k), $MachinePrecision]], $MachinePrecision] / k), $MachinePrecision]], $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \pi \cdot \left(2 \cdot n\right)\\
\mathbf{if}\;k \leq 3.5 \cdot 10^{-47}:\\
\;\;\;\;{k}^{-0.5} \cdot \sqrt{t_0}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\frac{{t_0}^{\left(1 - k\right)}}{k}}\\
\end{array}
\end{array}
if k < 3.4999999999999998e-47Initial program 99.2%
expm1-log1p-u92.0%
expm1-udef92.0%
pow1/292.0%
pow-flip92.0%
metadata-eval92.0%
Applied egg-rr92.0%
expm1-def92.0%
expm1-log1p99.3%
Simplified99.3%
Taylor expanded in k around 0 99.2%
pow199.2%
sqrt-unprod99.3%
*-commutative99.3%
Applied egg-rr99.3%
unpow199.3%
*-commutative99.3%
associate-*r*99.3%
Simplified99.3%
if 3.4999999999999998e-47 < k Initial program 99.7%
*-commutative99.7%
*-commutative99.7%
associate-*r*99.7%
div-inv99.7%
expm1-log1p-u99.4%
expm1-udef93.9%
Applied egg-rr93.3%
expm1-def98.8%
expm1-log1p99.1%
*-commutative99.1%
associate-*r*99.1%
Simplified99.1%
Final simplification99.2%
(FPCore (k n) :precision binary64 (* (pow k -0.5) (sqrt (* PI (* 2.0 n)))))
double code(double k, double n) {
return pow(k, -0.5) * sqrt((((double) M_PI) * (2.0 * n)));
}
public static double code(double k, double n) {
return Math.pow(k, -0.5) * Math.sqrt((Math.PI * (2.0 * n)));
}
def code(k, n): return math.pow(k, -0.5) * math.sqrt((math.pi * (2.0 * n)))
function code(k, n) return Float64((k ^ -0.5) * sqrt(Float64(pi * Float64(2.0 * n)))) end
function tmp = code(k, n) tmp = (k ^ -0.5) * sqrt((pi * (2.0 * n))); end
code[k_, n_] := N[(N[Power[k, -0.5], $MachinePrecision] * N[Sqrt[N[(Pi * N[(2.0 * n), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
{k}^{-0.5} \cdot \sqrt{\pi \cdot \left(2 \cdot n\right)}
\end{array}
Initial program 99.5%
expm1-log1p-u96.3%
expm1-udef69.0%
pow1/269.0%
pow-flip69.0%
metadata-eval69.0%
Applied egg-rr69.0%
expm1-def96.3%
expm1-log1p99.5%
Simplified99.5%
Taylor expanded in k around 0 47.3%
pow147.3%
sqrt-unprod47.4%
*-commutative47.4%
Applied egg-rr47.4%
unpow147.4%
*-commutative47.4%
associate-*r*47.4%
Simplified47.4%
Final simplification47.4%
(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 99.5%
*-commutative99.5%
*-commutative99.5%
associate-*r*99.5%
div-inv99.6%
expm1-log1p-u96.9%
expm1-udef86.1%
Applied egg-rr77.0%
expm1-def87.7%
expm1-log1p89.4%
*-commutative89.4%
associate-*r*89.4%
Simplified89.4%
pow-sub88.4%
pow188.4%
*-commutative88.4%
*-commutative88.4%
Applied egg-rr88.4%
Taylor expanded in k around 0 37.6%
associate-/l*37.6%
associate-/r/37.6%
Simplified37.6%
Final simplification37.6%
herbie shell --seed 2023215
(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))))