
(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 (let* ((t_0 (* 2.0 (* PI n)))) (/ (* (pow t_0 (* k -0.5)) (sqrt t_0)) (sqrt k))))
double code(double k, double n) {
double t_0 = 2.0 * (((double) M_PI) * n);
return (pow(t_0, (k * -0.5)) * sqrt(t_0)) / sqrt(k);
}
public static double code(double k, double n) {
double t_0 = 2.0 * (Math.PI * n);
return (Math.pow(t_0, (k * -0.5)) * Math.sqrt(t_0)) / Math.sqrt(k);
}
def code(k, n): t_0 = 2.0 * (math.pi * n) return (math.pow(t_0, (k * -0.5)) * math.sqrt(t_0)) / math.sqrt(k)
function code(k, n) t_0 = Float64(2.0 * Float64(pi * n)) return Float64(Float64((t_0 ^ Float64(k * -0.5)) * sqrt(t_0)) / sqrt(k)) end
function tmp = code(k, n) t_0 = 2.0 * (pi * n); tmp = ((t_0 ^ (k * -0.5)) * sqrt(t_0)) / sqrt(k); end
code[k_, n_] := Block[{t$95$0 = N[(2.0 * N[(Pi * n), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[Power[t$95$0, N[(k * -0.5), $MachinePrecision]], $MachinePrecision] * N[Sqrt[t$95$0], $MachinePrecision]), $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := 2 \cdot \left(\pi \cdot n\right)\\
\frac{{t_0}^{\left(k \cdot -0.5\right)} \cdot \sqrt{t_0}}{\sqrt{k}}
\end{array}
\end{array}
(FPCore (k n) :precision binary64 (if (<= k 2.45e-32) (* (sqrt (* 2.0 (* PI n))) (sqrt (/ 1.0 k))) (pow (/ k (pow (* PI (* 2.0 n)) (- 1.0 k))) -0.5)))
double code(double k, double n) {
double tmp;
if (k <= 2.45e-32) {
tmp = sqrt((2.0 * (((double) M_PI) * n))) * sqrt((1.0 / k));
} else {
tmp = pow((k / pow((((double) M_PI) * (2.0 * n)), (1.0 - k))), -0.5);
}
return tmp;
}
public static double code(double k, double n) {
double tmp;
if (k <= 2.45e-32) {
tmp = Math.sqrt((2.0 * (Math.PI * n))) * Math.sqrt((1.0 / k));
} else {
tmp = Math.pow((k / Math.pow((Math.PI * (2.0 * n)), (1.0 - k))), -0.5);
}
return tmp;
}
def code(k, n): tmp = 0 if k <= 2.45e-32: tmp = math.sqrt((2.0 * (math.pi * n))) * math.sqrt((1.0 / k)) else: tmp = math.pow((k / math.pow((math.pi * (2.0 * n)), (1.0 - k))), -0.5) return tmp
function code(k, n) tmp = 0.0 if (k <= 2.45e-32) tmp = Float64(sqrt(Float64(2.0 * Float64(pi * n))) * sqrt(Float64(1.0 / k))); else tmp = Float64(k / (Float64(pi * Float64(2.0 * n)) ^ Float64(1.0 - k))) ^ -0.5; end return tmp end
function tmp_2 = code(k, n) tmp = 0.0; if (k <= 2.45e-32) tmp = sqrt((2.0 * (pi * n))) * sqrt((1.0 / k)); else tmp = (k / ((pi * (2.0 * n)) ^ (1.0 - k))) ^ -0.5; end tmp_2 = tmp; end
code[k_, n_] := If[LessEqual[k, 2.45e-32], N[(N[Sqrt[N[(2.0 * N[(Pi * n), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[(1.0 / k), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[Power[N[(k / N[Power[N[(Pi * N[(2.0 * n), $MachinePrecision]), $MachinePrecision], N[(1.0 - k), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], -0.5], $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;k \leq 2.45 \cdot 10^{-32}:\\
\;\;\;\;\sqrt{2 \cdot \left(\pi \cdot n\right)} \cdot \sqrt{\frac{1}{k}}\\
\mathbf{else}:\\
\;\;\;\;{\left(\frac{k}{{\left(\pi \cdot \left(2 \cdot n\right)\right)}^{\left(1 - k\right)}}\right)}^{-0.5}\\
\end{array}
\end{array}
(FPCore (k n)
:precision binary64
(let* ((t_0 (* PI (* 2.0 n))))
(if (<= k 7.6e-41)
(/ (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 <= 7.6e-41) {
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 <= 7.6e-41) {
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 <= 7.6e-41: 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 <= 7.6e-41) 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 <= 7.6e-41) 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, 7.6e-41], 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 7.6 \cdot 10^{-41}:\\
\;\;\;\;\frac{\sqrt{t_0}}{\sqrt{k}}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\frac{{t_0}^{\left(1 - k\right)}}{k}}\\
\end{array}
\end{array}
(FPCore (k n) :precision binary64 (/ (pow (* PI (* 2.0 n)) (+ 0.5 (* k -0.5))) (sqrt k)))
double code(double k, double n) {
return pow((((double) M_PI) * (2.0 * n)), (0.5 + (k * -0.5))) / sqrt(k);
}
public static double code(double k, double n) {
return Math.pow((Math.PI * (2.0 * n)), (0.5 + (k * -0.5))) / Math.sqrt(k);
}
def code(k, n): return math.pow((math.pi * (2.0 * n)), (0.5 + (k * -0.5))) / math.sqrt(k)
function code(k, n) return Float64((Float64(pi * Float64(2.0 * n)) ^ Float64(0.5 + Float64(k * -0.5))) / sqrt(k)) end
function tmp = code(k, n) tmp = ((pi * (2.0 * n)) ^ (0.5 + (k * -0.5))) / sqrt(k); end
code[k_, n_] := N[(N[Power[N[(Pi * N[(2.0 * n), $MachinePrecision]), $MachinePrecision], N[(0.5 + N[(k * -0.5), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{{\left(\pi \cdot \left(2 \cdot n\right)\right)}^{\left(0.5 + k \cdot -0.5\right)}}{\sqrt{k}}
\end{array}
(FPCore (k n) :precision binary64 (/ (sqrt (* 2.0 n)) (sqrt (/ k PI))))
double code(double k, double n) {
return sqrt((2.0 * n)) / sqrt((k / ((double) M_PI)));
}
public static double code(double k, double n) {
return Math.sqrt((2.0 * n)) / Math.sqrt((k / Math.PI));
}
def code(k, n): return math.sqrt((2.0 * n)) / math.sqrt((k / math.pi))
function code(k, n) return Float64(sqrt(Float64(2.0 * n)) / sqrt(Float64(k / pi))) end
function tmp = code(k, n) tmp = sqrt((2.0 * n)) / sqrt((k / pi)); end
code[k_, n_] := N[(N[Sqrt[N[(2.0 * n), $MachinePrecision]], $MachinePrecision] / N[Sqrt[N[(k / Pi), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\sqrt{2 \cdot n}}{\sqrt{\frac{k}{\pi}}}
\end{array}
(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}
(FPCore (k n) :precision binary64 (sqrt (* 2.0 (* n (/ PI k)))))
double code(double k, double n) {
return sqrt((2.0 * (n * (((double) M_PI) / k))));
}
public static double code(double k, double n) {
return Math.sqrt((2.0 * (n * (Math.PI / k))));
}
def code(k, n): return math.sqrt((2.0 * (n * (math.pi / k))))
function code(k, n) return sqrt(Float64(2.0 * Float64(n * Float64(pi / k)))) end
function tmp = code(k, n) tmp = sqrt((2.0 * (n * (pi / k)))); end
code[k_, n_] := N[Sqrt[N[(2.0 * N[(n * N[(Pi / k), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{2 \cdot \left(n \cdot \frac{\pi}{k}\right)}
\end{array}
herbie shell --seed 2023350
(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))))