
(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 6 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 (* (* 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(Float64(2.0 * 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[(N[(2.0 * Pi), $MachinePrecision] * n), $MachinePrecision], N[(0.5 - N[(k / 2.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{{\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(0.5 - \frac{k}{2}\right)}}{\sqrt{k}}
\end{array}
Initial program 99.5%
associate-*l/99.6%
*-lft-identity99.6%
sqr-pow99.4%
pow-sqr99.6%
*-commutative99.6%
associate-*l/99.6%
associate-/l*99.6%
metadata-eval99.6%
/-rgt-identity99.6%
div-sub99.6%
metadata-eval99.6%
Simplified99.6%
Final simplification99.6%
(FPCore (k n)
:precision binary64
(let* ((t_0 (* PI (* 2.0 n))))
(if (<= k 1.42e-19)
(/ (sqrt t_0) (sqrt k))
(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 <= 1.42e-19) {
tmp = sqrt(t_0) / sqrt(k);
} 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 <= 1.42e-19) {
tmp = Math.sqrt(t_0) / Math.sqrt(k);
} 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 <= 1.42e-19: tmp = math.sqrt(t_0) / math.sqrt(k) 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 <= 1.42e-19) tmp = Float64(sqrt(t_0) / sqrt(k)); 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 <= 1.42e-19) tmp = sqrt(t_0) / sqrt(k); 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, 1.42e-19], N[(N[Sqrt[t$95$0], $MachinePrecision] / N[Sqrt[k], $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 1.42 \cdot 10^{-19}:\\
\;\;\;\;\frac{\sqrt{t_0}}{\sqrt{k}}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\frac{{t_0}^{\left(1 - k\right)}}{k}}\\
\end{array}
\end{array}
if k < 1.42e-19Initial program 99.3%
associate-*l/99.4%
*-lft-identity99.4%
sqr-pow99.1%
pow-sqr99.4%
*-commutative99.4%
associate-*l/99.4%
associate-/l*99.4%
metadata-eval99.4%
/-rgt-identity99.4%
div-sub99.4%
metadata-eval99.4%
Simplified99.4%
add-sqr-sqrt99.5%
pow299.5%
associate-*l*99.5%
Applied egg-rr99.5%
Taylor expanded in k around 0 99.2%
expm1-log1p-u96.3%
expm1-udef45.0%
sqrt-unprod45.0%
*-commutative45.0%
associate-*r*45.0%
*-commutative45.0%
Applied egg-rr45.0%
expm1-def96.4%
expm1-log1p99.5%
*-commutative99.5%
Simplified99.5%
if 1.42e-19 < k Initial program 99.7%
*-commutative99.7%
div-sub99.7%
metadata-eval99.7%
div-inv99.7%
expm1-log1p-u99.6%
expm1-udef97.3%
Applied egg-rr96.7%
expm1-def99.0%
expm1-log1p99.0%
associate-*r*99.0%
*-commutative99.0%
associate-*l*99.0%
Simplified99.0%
Final simplification99.2%
(FPCore (k n) :precision binary64 (/ (sqrt (* PI (* 2.0 n))) (sqrt k)))
double code(double k, double n) {
return sqrt((((double) M_PI) * (2.0 * n))) / sqrt(k);
}
public static double code(double k, double n) {
return Math.sqrt((Math.PI * (2.0 * n))) / Math.sqrt(k);
}
def code(k, n): return math.sqrt((math.pi * (2.0 * n))) / math.sqrt(k)
function code(k, n) return Float64(sqrt(Float64(pi * Float64(2.0 * n))) / sqrt(k)) end
function tmp = code(k, n) tmp = sqrt((pi * (2.0 * n))) / sqrt(k); end
code[k_, n_] := N[(N[Sqrt[N[(Pi * N[(2.0 * n), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\sqrt{\pi \cdot \left(2 \cdot n\right)}}{\sqrt{k}}
\end{array}
Initial program 99.5%
associate-*l/99.6%
*-lft-identity99.6%
sqr-pow99.4%
pow-sqr99.6%
*-commutative99.6%
associate-*l/99.6%
associate-/l*99.6%
metadata-eval99.6%
/-rgt-identity99.6%
div-sub99.6%
metadata-eval99.6%
Simplified99.6%
add-sqr-sqrt99.6%
pow299.6%
associate-*l*99.6%
Applied egg-rr99.6%
Taylor expanded in k around 0 52.6%
expm1-log1p-u51.1%
expm1-udef24.5%
sqrt-unprod24.5%
*-commutative24.5%
associate-*r*24.5%
*-commutative24.5%
Applied egg-rr24.5%
expm1-def51.2%
expm1-log1p52.7%
*-commutative52.7%
Simplified52.7%
Final simplification52.7%
(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 99.5%
associate-*l/99.6%
*-lft-identity99.6%
sqr-pow99.4%
pow-sqr99.6%
*-commutative99.6%
associate-*l/99.6%
associate-/l*99.6%
metadata-eval99.6%
/-rgt-identity99.6%
div-sub99.6%
metadata-eval99.6%
Simplified99.6%
add-sqr-sqrt99.6%
pow299.6%
associate-*l*99.6%
Applied egg-rr99.6%
Taylor expanded in k around 0 52.6%
expm1-log1p-u51.1%
expm1-udef24.5%
sqrt-unprod24.5%
*-commutative24.5%
associate-*r*24.5%
*-commutative24.5%
Applied egg-rr24.5%
expm1-def51.2%
expm1-log1p52.7%
*-commutative52.7%
Simplified52.7%
clear-num52.6%
inv-pow52.6%
sqrt-prod52.4%
*-commutative52.4%
sqrt-prod52.6%
sqrt-undiv43.0%
associate-*r*43.0%
*-commutative43.0%
associate-*l*43.0%
Applied egg-rr43.0%
unpow-143.0%
associate-/r*43.0%
*-commutative43.0%
Simplified43.0%
Final simplification43.0%
(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%
div-sub99.5%
metadata-eval99.5%
div-inv99.6%
expm1-log1p-u96.8%
expm1-udef84.8%
Applied egg-rr74.7%
expm1-def86.8%
expm1-log1p88.4%
associate-*r*88.4%
*-commutative88.4%
associate-*l*88.4%
Simplified88.4%
Taylor expanded in k around 0 41.8%
associate-/l*41.8%
associate-/r/41.7%
Simplified41.7%
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 99.5%
*-commutative99.5%
div-sub99.5%
metadata-eval99.5%
div-inv99.6%
expm1-log1p-u96.8%
expm1-udef84.8%
Applied egg-rr74.7%
expm1-def86.8%
expm1-log1p88.4%
associate-*r*88.4%
*-commutative88.4%
associate-*l*88.4%
Simplified88.4%
Taylor expanded in k around 0 41.8%
associate-/l*41.8%
associate-/r/41.7%
Simplified41.7%
Taylor expanded in n around 0 41.8%
*-commutative41.8%
associate-/l*41.8%
Simplified41.8%
Final simplification41.8%
herbie shell --seed 2023278
(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))))