Migdal et al, Equation (51)

Percentage Accurate: 99.4% → 99.5%
Time: 6.2s
Alternatives: 8
Speedup: 1.2×

Specification

?
\[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
(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]
\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 8 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 99.4% accurate, 1.0× speedup?

\[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
(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]
\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}

Alternative 1: 99.5% accurate, 1.2× speedup?

\[\frac{{\left(n \cdot 6.283185307179586\right)}^{\left(\mathsf{fma}\left(k, -0.5, 0.5\right)\right)}}{\sqrt{k}} \]
(FPCore (k n)
 :precision binary64
 (/ (pow (* n 6.283185307179586) (fma k -0.5 0.5)) (sqrt k)))
double code(double k, double n) {
	return pow((n * 6.283185307179586), fma(k, -0.5, 0.5)) / sqrt(k);
}
function code(k, n)
	return Float64((Float64(n * 6.283185307179586) ^ fma(k, -0.5, 0.5)) / sqrt(k))
end
code[k_, n_] := N[(N[Power[N[(n * 6.283185307179586), $MachinePrecision], N[(k * -0.5 + 0.5), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]
\frac{{\left(n \cdot 6.283185307179586\right)}^{\left(\mathsf{fma}\left(k, -0.5, 0.5\right)\right)}}{\sqrt{k}}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
  2. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \color{blue}{\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}} \]
    2. *-commutativeN/A

      \[\leadsto \color{blue}{{\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \cdot \frac{1}{\sqrt{k}}} \]
    3. lift-/.f64N/A

      \[\leadsto {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \cdot \color{blue}{\frac{1}{\sqrt{k}}} \]
    4. mult-flip-revN/A

      \[\leadsto \color{blue}{\frac{{\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}}{\sqrt{k}}} \]
    5. lower-/.f6499.5

      \[\leadsto \color{blue}{\frac{{\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}}{\sqrt{k}}} \]
  3. Applied rewrites99.5%

    \[\leadsto \color{blue}{\frac{{\left(n \cdot \left(\pi + \pi\right)\right)}^{\left(\mathsf{fma}\left(k, -0.5, 0.5\right)\right)}}{\sqrt{k}}} \]
  4. Evaluated real constant99.5%

    \[\leadsto \frac{{\left(n \cdot \color{blue}{\frac{884279719003555}{140737488355328}}\right)}^{\left(\mathsf{fma}\left(k, \frac{-1}{2}, \frac{1}{2}\right)\right)}}{\sqrt{k}} \]
  5. Add Preprocessing

Alternative 2: 98.0% accurate, 1.2× speedup?

\[\begin{array}{l} \mathbf{if}\;k \leq 2.3:\\ \;\;\;\;\frac{n \cdot \sqrt{2 \cdot \frac{\pi}{n}}}{\sqrt{k}}\\ \mathbf{else}:\\ \;\;\;\;\frac{{\left(n \cdot 6.283185307179586\right)}^{\left(-0.5 \cdot k\right)}}{\sqrt{k}}\\ \end{array} \]
(FPCore (k n)
 :precision binary64
 (if (<= k 2.3)
   (/ (* n (sqrt (* 2.0 (/ PI n)))) (sqrt k))
   (/ (pow (* n 6.283185307179586) (* -0.5 k)) (sqrt k))))
double code(double k, double n) {
	double tmp;
	if (k <= 2.3) {
		tmp = (n * sqrt((2.0 * (((double) M_PI) / n)))) / sqrt(k);
	} else {
		tmp = pow((n * 6.283185307179586), (-0.5 * k)) / sqrt(k);
	}
	return tmp;
}
public static double code(double k, double n) {
	double tmp;
	if (k <= 2.3) {
		tmp = (n * Math.sqrt((2.0 * (Math.PI / n)))) / Math.sqrt(k);
	} else {
		tmp = Math.pow((n * 6.283185307179586), (-0.5 * k)) / Math.sqrt(k);
	}
	return tmp;
}
def code(k, n):
	tmp = 0
	if k <= 2.3:
		tmp = (n * math.sqrt((2.0 * (math.pi / n)))) / math.sqrt(k)
	else:
		tmp = math.pow((n * 6.283185307179586), (-0.5 * k)) / math.sqrt(k)
	return tmp
function code(k, n)
	tmp = 0.0
	if (k <= 2.3)
		tmp = Float64(Float64(n * sqrt(Float64(2.0 * Float64(pi / n)))) / sqrt(k));
	else
		tmp = Float64((Float64(n * 6.283185307179586) ^ Float64(-0.5 * k)) / sqrt(k));
	end
	return tmp
end
function tmp_2 = code(k, n)
	tmp = 0.0;
	if (k <= 2.3)
		tmp = (n * sqrt((2.0 * (pi / n)))) / sqrt(k);
	else
		tmp = ((n * 6.283185307179586) ^ (-0.5 * k)) / sqrt(k);
	end
	tmp_2 = tmp;
end
code[k_, n_] := If[LessEqual[k, 2.3], N[(N[(n * N[Sqrt[N[(2.0 * N[(Pi / n), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision], N[(N[Power[N[(n * 6.283185307179586), $MachinePrecision], N[(-0.5 * k), $MachinePrecision]], $MachinePrecision] / N[Sqrt[k], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\mathbf{if}\;k \leq 2.3:\\
\;\;\;\;\frac{n \cdot \sqrt{2 \cdot \frac{\pi}{n}}}{\sqrt{k}}\\

\mathbf{else}:\\
\;\;\;\;\frac{{\left(n \cdot 6.283185307179586\right)}^{\left(-0.5 \cdot k\right)}}{\sqrt{k}}\\


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if k < 2.2999999999999998

    1. Initial program 99.4%

      \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    2. Taylor expanded in k around 0

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
    3. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
      2. lower-pow.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
      3. lower-*.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      5. lower-PI.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      6. lower-sqrt.f6449.5

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}} \]
    4. Applied rewrites49.5%

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}}} \]
    5. Taylor expanded in n around inf

      \[\leadsto \frac{n \cdot \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{n}}}{\sqrt{\color{blue}{k}}} \]
    6. Step-by-step derivation
      1. lower-*.f64N/A

        \[\leadsto \frac{n \cdot \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{n}}}{\sqrt{k}} \]
      2. lower-sqrt.f64N/A

        \[\leadsto \frac{n \cdot \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{n}}}{\sqrt{k}} \]
      3. lower-*.f64N/A

        \[\leadsto \frac{n \cdot \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{n}}}{\sqrt{k}} \]
      4. lower-/.f64N/A

        \[\leadsto \frac{n \cdot \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{n}}}{\sqrt{k}} \]
      5. lower-PI.f6449.5

        \[\leadsto \frac{n \cdot \sqrt{2 \cdot \frac{\pi}{n}}}{\sqrt{k}} \]
    7. Applied rewrites49.5%

      \[\leadsto \frac{n \cdot \sqrt{2 \cdot \frac{\pi}{n}}}{\sqrt{\color{blue}{k}}} \]

    if 2.2999999999999998 < k

    1. Initial program 99.4%

      \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    2. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \color{blue}{\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}} \]
      2. *-commutativeN/A

        \[\leadsto \color{blue}{{\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \cdot \frac{1}{\sqrt{k}}} \]
      3. lift-/.f64N/A

        \[\leadsto {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \cdot \color{blue}{\frac{1}{\sqrt{k}}} \]
      4. mult-flip-revN/A

        \[\leadsto \color{blue}{\frac{{\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}}{\sqrt{k}}} \]
      5. lower-/.f6499.5

        \[\leadsto \color{blue}{\frac{{\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}}{\sqrt{k}}} \]
    3. Applied rewrites99.5%

      \[\leadsto \color{blue}{\frac{{\left(n \cdot \left(\pi + \pi\right)\right)}^{\left(\mathsf{fma}\left(k, -0.5, 0.5\right)\right)}}{\sqrt{k}}} \]
    4. Evaluated real constant99.5%

      \[\leadsto \frac{{\left(n \cdot \color{blue}{\frac{884279719003555}{140737488355328}}\right)}^{\left(\mathsf{fma}\left(k, \frac{-1}{2}, \frac{1}{2}\right)\right)}}{\sqrt{k}} \]
    5. Taylor expanded in k around inf

      \[\leadsto \frac{{\left(n \cdot \frac{884279719003555}{140737488355328}\right)}^{\color{blue}{\left(\frac{-1}{2} \cdot k\right)}}}{\sqrt{k}} \]
    6. Step-by-step derivation
      1. lower-*.f6453.3

        \[\leadsto \frac{{\left(n \cdot 6.283185307179586\right)}^{\left(-0.5 \cdot \color{blue}{k}\right)}}{\sqrt{k}} \]
    7. Applied rewrites53.3%

      \[\leadsto \frac{{\left(n \cdot 6.283185307179586\right)}^{\color{blue}{\left(-0.5 \cdot k\right)}}}{\sqrt{k}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 72.9% accurate, 0.4× speedup?

\[\begin{array}{l} t_0 := \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}\\ \mathbf{if}\;t\_0 \leq 0:\\ \;\;\;\;n \cdot \sqrt{2 \cdot \frac{\pi}{k \cdot n}}\\ \mathbf{elif}\;t\_0 \leq 2 \cdot 10^{+286}:\\ \;\;\;\;\sqrt{\frac{\pi}{k}} \cdot \sqrt{n + n}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\left(k + k\right) \cdot \left(k + k\right)}}}{k}\\ \end{array} \]
(FPCore (k n)
 :precision binary64
 (let* ((t_0 (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0)))))
   (if (<= t_0 0.0)
     (* n (sqrt (* 2.0 (/ PI (* k n)))))
     (if (<= t_0 2e+286)
       (* (sqrt (/ PI k)) (sqrt (+ n n)))
       (* (sqrt (* PI n)) (/ (sqrt (sqrt (* (+ k k) (+ k k)))) k))))))
double code(double k, double n) {
	double t_0 = (1.0 / sqrt(k)) * pow(((2.0 * ((double) M_PI)) * n), ((1.0 - k) / 2.0));
	double tmp;
	if (t_0 <= 0.0) {
		tmp = n * sqrt((2.0 * (((double) M_PI) / (k * n))));
	} else if (t_0 <= 2e+286) {
		tmp = sqrt((((double) M_PI) / k)) * sqrt((n + n));
	} else {
		tmp = sqrt((((double) M_PI) * n)) * (sqrt(sqrt(((k + k) * (k + k)))) / k);
	}
	return tmp;
}
public static double code(double k, double n) {
	double t_0 = (1.0 / Math.sqrt(k)) * Math.pow(((2.0 * Math.PI) * n), ((1.0 - k) / 2.0));
	double tmp;
	if (t_0 <= 0.0) {
		tmp = n * Math.sqrt((2.0 * (Math.PI / (k * n))));
	} else if (t_0 <= 2e+286) {
		tmp = Math.sqrt((Math.PI / k)) * Math.sqrt((n + n));
	} else {
		tmp = Math.sqrt((Math.PI * n)) * (Math.sqrt(Math.sqrt(((k + k) * (k + k)))) / k);
	}
	return tmp;
}
def code(k, n):
	t_0 = (1.0 / math.sqrt(k)) * math.pow(((2.0 * math.pi) * n), ((1.0 - k) / 2.0))
	tmp = 0
	if t_0 <= 0.0:
		tmp = n * math.sqrt((2.0 * (math.pi / (k * n))))
	elif t_0 <= 2e+286:
		tmp = math.sqrt((math.pi / k)) * math.sqrt((n + n))
	else:
		tmp = math.sqrt((math.pi * n)) * (math.sqrt(math.sqrt(((k + k) * (k + k)))) / k)
	return tmp
function code(k, n)
	t_0 = Float64(Float64(1.0 / sqrt(k)) * (Float64(Float64(2.0 * pi) * n) ^ Float64(Float64(1.0 - k) / 2.0)))
	tmp = 0.0
	if (t_0 <= 0.0)
		tmp = Float64(n * sqrt(Float64(2.0 * Float64(pi / Float64(k * n)))));
	elseif (t_0 <= 2e+286)
		tmp = Float64(sqrt(Float64(pi / k)) * sqrt(Float64(n + n)));
	else
		tmp = Float64(sqrt(Float64(pi * n)) * Float64(sqrt(sqrt(Float64(Float64(k + k) * Float64(k + k)))) / k));
	end
	return tmp
end
function tmp_2 = code(k, n)
	t_0 = (1.0 / sqrt(k)) * (((2.0 * pi) * n) ^ ((1.0 - k) / 2.0));
	tmp = 0.0;
	if (t_0 <= 0.0)
		tmp = n * sqrt((2.0 * (pi / (k * n))));
	elseif (t_0 <= 2e+286)
		tmp = sqrt((pi / k)) * sqrt((n + n));
	else
		tmp = sqrt((pi * n)) * (sqrt(sqrt(((k + k) * (k + k)))) / k);
	end
	tmp_2 = tmp;
end
code[k_, n_] := Block[{t$95$0 = 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]}, If[LessEqual[t$95$0, 0.0], N[(n * N[Sqrt[N[(2.0 * N[(Pi / N[(k * n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$0, 2e+286], N[(N[Sqrt[N[(Pi / k), $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[(n + n), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(N[Sqrt[N[(Pi * n), $MachinePrecision]], $MachinePrecision] * N[(N[Sqrt[N[Sqrt[N[(N[(k + k), $MachinePrecision] * N[(k + k), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] / k), $MachinePrecision]), $MachinePrecision]]]]
\begin{array}{l}
t_0 := \frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}\\
\mathbf{if}\;t\_0 \leq 0:\\
\;\;\;\;n \cdot \sqrt{2 \cdot \frac{\pi}{k \cdot n}}\\

\mathbf{elif}\;t\_0 \leq 2 \cdot 10^{+286}:\\
\;\;\;\;\sqrt{\frac{\pi}{k}} \cdot \sqrt{n + n}\\

\mathbf{else}:\\
\;\;\;\;\sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\left(k + k\right) \cdot \left(k + k\right)}}}{k}\\


\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 (/.f64 #s(literal 1 binary64) (sqrt.f64 k)) (pow.f64 (*.f64 (*.f64 #s(literal 2 binary64) (PI.f64)) n) (/.f64 (-.f64 #s(literal 1 binary64) k) #s(literal 2 binary64)))) < 0.0

    1. Initial program 99.4%

      \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    2. Taylor expanded in k around 0

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
    3. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
      2. lower-pow.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
      3. lower-*.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      5. lower-PI.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      6. lower-sqrt.f6449.5

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}} \]
    4. Applied rewrites49.5%

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}}} \]
    5. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
      2. lift-pow.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
      3. unpow1/2N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{\color{blue}{k}}} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{k}} \]
      5. count-2-revN/A

        \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
      6. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
      7. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
      8. distribute-lft-inN/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      9. lift-+.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      10. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      11. lift-sqrt.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      12. sqrt-undivN/A

        \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
      13. lower-sqrt.f64N/A

        \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
    6. Applied rewrites37.9%

      \[\leadsto \sqrt{\left(n + n\right) \cdot \frac{\pi}{k}} \]
    7. Taylor expanded in n around inf

      \[\leadsto n \cdot \color{blue}{\sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}}} \]
    8. Step-by-step derivation
      1. lower-*.f64N/A

        \[\leadsto n \cdot \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}} \]
      2. lower-sqrt.f64N/A

        \[\leadsto n \cdot \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}} \]
      3. lower-*.f64N/A

        \[\leadsto n \cdot \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}} \]
      4. lower-/.f64N/A

        \[\leadsto n \cdot \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}} \]
      5. lower-PI.f64N/A

        \[\leadsto n \cdot \sqrt{2 \cdot \frac{\pi}{k \cdot n}} \]
      6. lower-*.f6448.6

        \[\leadsto n \cdot \sqrt{2 \cdot \frac{\pi}{k \cdot n}} \]
    9. Applied rewrites48.6%

      \[\leadsto n \cdot \color{blue}{\sqrt{2 \cdot \frac{\pi}{k \cdot n}}} \]

    if 0.0 < (*.f64 (/.f64 #s(literal 1 binary64) (sqrt.f64 k)) (pow.f64 (*.f64 (*.f64 #s(literal 2 binary64) (PI.f64)) n) (/.f64 (-.f64 #s(literal 1 binary64) k) #s(literal 2 binary64)))) < 2.00000000000000007e286

    1. Initial program 99.4%

      \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    2. Taylor expanded in k around 0

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
    3. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
      2. lower-pow.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
      3. lower-*.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      5. lower-PI.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      6. lower-sqrt.f6449.5

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}} \]
    4. Applied rewrites49.5%

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}}} \]
    5. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
      2. lift-pow.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
      3. unpow1/2N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{\color{blue}{k}}} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{k}} \]
      5. count-2-revN/A

        \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
      6. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
      7. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
      8. distribute-lft-inN/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      9. lift-+.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      10. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      11. lift-sqrt.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      12. sqrt-undivN/A

        \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
      13. lower-sqrt.f64N/A

        \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
    6. Applied rewrites37.9%

      \[\leadsto \sqrt{\left(n + n\right) \cdot \frac{\pi}{k}} \]
    7. Step-by-step derivation
      1. lift-sqrt.f64N/A

        \[\leadsto \sqrt{\left(n + n\right) \cdot \frac{\pi}{k}} \]
      2. lift-*.f64N/A

        \[\leadsto \sqrt{\left(n + n\right) \cdot \frac{\pi}{k}} \]
      3. *-commutativeN/A

        \[\leadsto \sqrt{\frac{\pi}{k} \cdot \left(n + n\right)} \]
      4. sqrt-prodN/A

        \[\leadsto \sqrt{\frac{\pi}{k}} \cdot \color{blue}{\sqrt{n + n}} \]
      5. lower-unsound-*.f64N/A

        \[\leadsto \sqrt{\frac{\pi}{k}} \cdot \color{blue}{\sqrt{n + n}} \]
      6. lower-unsound-sqrt.f64N/A

        \[\leadsto \sqrt{\frac{\pi}{k}} \cdot \sqrt{\color{blue}{n + n}} \]
      7. lower-unsound-sqrt.f6449.5

        \[\leadsto \sqrt{\frac{\pi}{k}} \cdot \sqrt{n + n} \]
    8. Applied rewrites49.5%

      \[\leadsto \sqrt{\frac{\pi}{k}} \cdot \color{blue}{\sqrt{n + n}} \]

    if 2.00000000000000007e286 < (*.f64 (/.f64 #s(literal 1 binary64) (sqrt.f64 k)) (pow.f64 (*.f64 (*.f64 #s(literal 2 binary64) (PI.f64)) n) (/.f64 (-.f64 #s(literal 1 binary64) k) #s(literal 2 binary64))))

    1. Initial program 99.4%

      \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    2. Taylor expanded in k around 0

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
    3. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
      2. lower-pow.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
      3. lower-*.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      5. lower-PI.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      6. lower-sqrt.f6449.5

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}} \]
    4. Applied rewrites49.5%

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}}} \]
    5. Taylor expanded in k around inf

      \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}}{\color{blue}{k \cdot \sqrt{\frac{1}{k}}}} \]
    6. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}}{k \cdot \color{blue}{\sqrt{\frac{1}{k}}}} \]
      2. lower-sqrt.f64N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}}{k \cdot \sqrt{\color{blue}{\frac{1}{k}}}} \]
      3. lower-*.f64N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}}{k \cdot \sqrt{\frac{\color{blue}{1}}{k}}} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)}}{k \cdot \sqrt{\frac{1}{k}}} \]
      5. lower-PI.f64N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{k \cdot \sqrt{\frac{1}{k}}} \]
      6. lower-*.f64N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{k \cdot \sqrt{\frac{1}{k}}} \]
      7. lower-sqrt.f64N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{k \cdot \sqrt{\frac{1}{k}}} \]
      8. lower-/.f6449.4

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{k \cdot \sqrt{\frac{1}{k}}} \]
    7. Applied rewrites49.4%

      \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\color{blue}{k \cdot \sqrt{\frac{1}{k}}}} \]
    8. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{k \cdot \color{blue}{\sqrt{\frac{1}{k}}}} \]
      2. mult-flipN/A

        \[\leadsto \sqrt{2 \cdot \left(n \cdot \pi\right)} \cdot \frac{1}{\color{blue}{k \cdot \sqrt{\frac{1}{k}}}} \]
      3. lift-sqrt.f64N/A

        \[\leadsto \sqrt{2 \cdot \left(n \cdot \pi\right)} \cdot \frac{1}{\color{blue}{k} \cdot \sqrt{\frac{1}{k}}} \]
      4. lift-*.f64N/A

        \[\leadsto \sqrt{2 \cdot \left(n \cdot \pi\right)} \cdot \frac{1}{k \cdot \sqrt{\frac{1}{k}}} \]
      5. *-commutativeN/A

        \[\leadsto \sqrt{\left(n \cdot \pi\right) \cdot 2} \cdot \frac{1}{k \cdot \sqrt{\frac{1}{k}}} \]
      6. lift-*.f64N/A

        \[\leadsto \sqrt{\left(n \cdot \pi\right) \cdot 2} \cdot \frac{1}{k \cdot \sqrt{\frac{1}{k}}} \]
      7. *-commutativeN/A

        \[\leadsto \sqrt{\left(\pi \cdot n\right) \cdot 2} \cdot \frac{1}{k \cdot \sqrt{\frac{1}{k}}} \]
      8. lift-*.f64N/A

        \[\leadsto \sqrt{\left(\pi \cdot n\right) \cdot 2} \cdot \frac{1}{k \cdot \sqrt{\frac{1}{k}}} \]
      9. sqrt-unprodN/A

        \[\leadsto \left(\sqrt{\pi \cdot n} \cdot \sqrt{2}\right) \cdot \frac{1}{\color{blue}{k} \cdot \sqrt{\frac{1}{k}}} \]
      10. lift-sqrt.f64N/A

        \[\leadsto \left(\sqrt{\pi \cdot n} \cdot \sqrt{2}\right) \cdot \frac{1}{k \cdot \sqrt{\frac{1}{k}}} \]
      11. lift-sqrt.f64N/A

        \[\leadsto \left(\sqrt{\pi \cdot n} \cdot \sqrt{2}\right) \cdot \frac{1}{k \cdot \sqrt{\frac{1}{k}}} \]
      12. associate-*l*N/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \left(\sqrt{2} \cdot \color{blue}{\frac{1}{k \cdot \sqrt{\frac{1}{k}}}}\right) \]
      13. lower-*.f64N/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \left(\sqrt{2} \cdot \color{blue}{\frac{1}{k \cdot \sqrt{\frac{1}{k}}}}\right) \]
      14. mult-flip-revN/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{2}}{k \cdot \color{blue}{\sqrt{\frac{1}{k}}}} \]
      15. lift-*.f64N/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{2}}{k \cdot \sqrt{\frac{1}{k}}} \]
      16. *-commutativeN/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{2}}{\sqrt{\frac{1}{k}} \cdot k} \]
      17. associate-/r*N/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\frac{\sqrt{2}}{\sqrt{\frac{1}{k}}}}{k} \]
      18. lower-/.f64N/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\frac{\sqrt{2}}{\sqrt{\frac{1}{k}}}}{k} \]
    9. Applied rewrites49.4%

      \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\frac{2}{\frac{1}{k}}}}{\color{blue}{k}} \]
    10. Step-by-step derivation
      1. rem-square-sqrtN/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\frac{2}{\frac{1}{k}}} \cdot \sqrt{\frac{2}{\frac{1}{k}}}}}{k} \]
      2. sqrt-unprodN/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\frac{2}{\frac{1}{k}} \cdot \frac{2}{\frac{1}{k}}}}}{k} \]
      3. lower-sqrt.f64N/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\frac{2}{\frac{1}{k}} \cdot \frac{2}{\frac{1}{k}}}}}{k} \]
      4. lower-*.f6438.5

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\frac{2}{\frac{1}{k}} \cdot \frac{2}{\frac{1}{k}}}}}{k} \]
      5. lift-/.f64N/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\frac{2}{\frac{1}{k}} \cdot \frac{2}{\frac{1}{k}}}}}{k} \]
      6. lift-/.f64N/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\frac{2}{\frac{1}{k}} \cdot \frac{2}{\frac{1}{k}}}}}{k} \]
      7. associate-/r/N/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\left(\frac{2}{1} \cdot k\right) \cdot \frac{2}{\frac{1}{k}}}}}{k} \]
      8. metadata-evalN/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\left(2 \cdot k\right) \cdot \frac{2}{\frac{1}{k}}}}}{k} \]
      9. count-2-revN/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\left(k + k\right) \cdot \frac{2}{\frac{1}{k}}}}}{k} \]
      10. lower-+.f6438.5

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\left(k + k\right) \cdot \frac{2}{\frac{1}{k}}}}}{k} \]
      11. lift-/.f64N/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\left(k + k\right) \cdot \frac{2}{\frac{1}{k}}}}}{k} \]
      12. lift-/.f64N/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\left(k + k\right) \cdot \frac{2}{\frac{1}{k}}}}}{k} \]
      13. associate-/r/N/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\left(k + k\right) \cdot \left(\frac{2}{1} \cdot k\right)}}}{k} \]
      14. metadata-evalN/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\left(k + k\right) \cdot \left(2 \cdot k\right)}}}{k} \]
      15. count-2-revN/A

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\left(k + k\right) \cdot \left(k + k\right)}}}{k} \]
      16. lower-+.f6438.5

        \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\left(k + k\right) \cdot \left(k + k\right)}}}{k} \]
    11. Applied rewrites38.5%

      \[\leadsto \sqrt{\pi \cdot n} \cdot \frac{\sqrt{\sqrt{\left(k + k\right) \cdot \left(k + k\right)}}}{k} \]
  3. Recombined 3 regimes into one program.
  4. Add Preprocessing

Alternative 4: 61.0% accurate, 2.0× speedup?

\[\begin{array}{l} \mathbf{if}\;n \leq 200000000:\\ \;\;\;\;\sqrt{\left|\frac{\pi + \pi}{k} \cdot n\right|}\\ \mathbf{else}:\\ \;\;\;\;n \cdot \sqrt{2 \cdot \frac{\pi}{k \cdot n}}\\ \end{array} \]
(FPCore (k n)
 :precision binary64
 (if (<= n 200000000.0)
   (sqrt (fabs (* (/ (+ PI PI) k) n)))
   (* n (sqrt (* 2.0 (/ PI (* k n)))))))
double code(double k, double n) {
	double tmp;
	if (n <= 200000000.0) {
		tmp = sqrt(fabs((((((double) M_PI) + ((double) M_PI)) / k) * n)));
	} else {
		tmp = n * sqrt((2.0 * (((double) M_PI) / (k * n))));
	}
	return tmp;
}
public static double code(double k, double n) {
	double tmp;
	if (n <= 200000000.0) {
		tmp = Math.sqrt(Math.abs((((Math.PI + Math.PI) / k) * n)));
	} else {
		tmp = n * Math.sqrt((2.0 * (Math.PI / (k * n))));
	}
	return tmp;
}
def code(k, n):
	tmp = 0
	if n <= 200000000.0:
		tmp = math.sqrt(math.fabs((((math.pi + math.pi) / k) * n)))
	else:
		tmp = n * math.sqrt((2.0 * (math.pi / (k * n))))
	return tmp
function code(k, n)
	tmp = 0.0
	if (n <= 200000000.0)
		tmp = sqrt(abs(Float64(Float64(Float64(pi + pi) / k) * n)));
	else
		tmp = Float64(n * sqrt(Float64(2.0 * Float64(pi / Float64(k * n)))));
	end
	return tmp
end
function tmp_2 = code(k, n)
	tmp = 0.0;
	if (n <= 200000000.0)
		tmp = sqrt(abs((((pi + pi) / k) * n)));
	else
		tmp = n * sqrt((2.0 * (pi / (k * n))));
	end
	tmp_2 = tmp;
end
code[k_, n_] := If[LessEqual[n, 200000000.0], N[Sqrt[N[Abs[N[(N[(N[(Pi + Pi), $MachinePrecision] / k), $MachinePrecision] * n), $MachinePrecision]], $MachinePrecision]], $MachinePrecision], N[(n * N[Sqrt[N[(2.0 * N[(Pi / N[(k * n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\mathbf{if}\;n \leq 200000000:\\
\;\;\;\;\sqrt{\left|\frac{\pi + \pi}{k} \cdot n\right|}\\

\mathbf{else}:\\
\;\;\;\;n \cdot \sqrt{2 \cdot \frac{\pi}{k \cdot n}}\\


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if n < 2e8

    1. Initial program 99.4%

      \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    2. Taylor expanded in k around 0

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
    3. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
      2. lower-pow.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
      3. lower-*.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      5. lower-PI.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      6. lower-sqrt.f6449.5

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}} \]
    4. Applied rewrites49.5%

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}}} \]
    5. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
      2. lift-pow.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
      3. unpow1/2N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{\color{blue}{k}}} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{k}} \]
      5. count-2-revN/A

        \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
      6. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
      7. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
      8. distribute-lft-inN/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      9. lift-+.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      10. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      11. lift-sqrt.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      12. sqrt-undivN/A

        \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
      13. lower-sqrt.f64N/A

        \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
    6. Applied rewrites37.9%

      \[\leadsto \sqrt{\left(n + n\right) \cdot \frac{\pi}{k}} \]
    7. Applied rewrites37.9%

      \[\leadsto \sqrt{\left|\frac{\pi + \pi}{k} \cdot n\right|} \]

    if 2e8 < n

    1. Initial program 99.4%

      \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
    2. Taylor expanded in k around 0

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
    3. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
      2. lower-pow.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
      3. lower-*.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      5. lower-PI.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
      6. lower-sqrt.f6449.5

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}} \]
    4. Applied rewrites49.5%

      \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}}} \]
    5. Step-by-step derivation
      1. lift-/.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
      2. lift-pow.f64N/A

        \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
      3. unpow1/2N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{\color{blue}{k}}} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{k}} \]
      5. count-2-revN/A

        \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
      6. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
      7. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
      8. distribute-lft-inN/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      9. lift-+.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      10. lift-*.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      11. lift-sqrt.f64N/A

        \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
      12. sqrt-undivN/A

        \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
      13. lower-sqrt.f64N/A

        \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
    6. Applied rewrites37.9%

      \[\leadsto \sqrt{\left(n + n\right) \cdot \frac{\pi}{k}} \]
    7. Taylor expanded in n around inf

      \[\leadsto n \cdot \color{blue}{\sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}}} \]
    8. Step-by-step derivation
      1. lower-*.f64N/A

        \[\leadsto n \cdot \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}} \]
      2. lower-sqrt.f64N/A

        \[\leadsto n \cdot \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}} \]
      3. lower-*.f64N/A

        \[\leadsto n \cdot \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}} \]
      4. lower-/.f64N/A

        \[\leadsto n \cdot \sqrt{2 \cdot \frac{\mathsf{PI}\left(\right)}{k \cdot n}} \]
      5. lower-PI.f64N/A

        \[\leadsto n \cdot \sqrt{2 \cdot \frac{\pi}{k \cdot n}} \]
      6. lower-*.f6448.6

        \[\leadsto n \cdot \sqrt{2 \cdot \frac{\pi}{k \cdot n}} \]
    9. Applied rewrites48.6%

      \[\leadsto n \cdot \color{blue}{\sqrt{2 \cdot \frac{\pi}{k \cdot n}}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 5: 49.5% accurate, 2.7× speedup?

\[\sqrt{\frac{\pi}{k}} \cdot \sqrt{n + n} \]
(FPCore (k n) :precision binary64 (* (sqrt (/ PI k)) (sqrt (+ n n))))
double code(double k, double n) {
	return sqrt((((double) M_PI) / k)) * sqrt((n + n));
}
public static double code(double k, double n) {
	return Math.sqrt((Math.PI / k)) * Math.sqrt((n + n));
}
def code(k, n):
	return math.sqrt((math.pi / k)) * math.sqrt((n + n))
function code(k, n)
	return Float64(sqrt(Float64(pi / k)) * sqrt(Float64(n + n)))
end
function tmp = code(k, n)
	tmp = sqrt((pi / k)) * sqrt((n + n));
end
code[k_, n_] := N[(N[Sqrt[N[(Pi / k), $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[(n + n), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\sqrt{\frac{\pi}{k}} \cdot \sqrt{n + n}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
  2. Taylor expanded in k around 0

    \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
  3. Step-by-step derivation
    1. lower-/.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
    2. lower-pow.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
    3. lower-*.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
    4. lower-*.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
    5. lower-PI.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
    6. lower-sqrt.f6449.5

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}} \]
  4. Applied rewrites49.5%

    \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}}} \]
  5. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
    2. lift-pow.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
    3. unpow1/2N/A

      \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{\color{blue}{k}}} \]
    4. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{k}} \]
    5. count-2-revN/A

      \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
    6. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
    7. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
    8. distribute-lft-inN/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    9. lift-+.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    10. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    11. lift-sqrt.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    12. sqrt-undivN/A

      \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
    13. lower-sqrt.f64N/A

      \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
  6. Applied rewrites37.9%

    \[\leadsto \sqrt{\left(n + n\right) \cdot \frac{\pi}{k}} \]
  7. Step-by-step derivation
    1. lift-sqrt.f64N/A

      \[\leadsto \sqrt{\left(n + n\right) \cdot \frac{\pi}{k}} \]
    2. lift-*.f64N/A

      \[\leadsto \sqrt{\left(n + n\right) \cdot \frac{\pi}{k}} \]
    3. *-commutativeN/A

      \[\leadsto \sqrt{\frac{\pi}{k} \cdot \left(n + n\right)} \]
    4. sqrt-prodN/A

      \[\leadsto \sqrt{\frac{\pi}{k}} \cdot \color{blue}{\sqrt{n + n}} \]
    5. lower-unsound-*.f64N/A

      \[\leadsto \sqrt{\frac{\pi}{k}} \cdot \color{blue}{\sqrt{n + n}} \]
    6. lower-unsound-sqrt.f64N/A

      \[\leadsto \sqrt{\frac{\pi}{k}} \cdot \sqrt{\color{blue}{n + n}} \]
    7. lower-unsound-sqrt.f6449.5

      \[\leadsto \sqrt{\frac{\pi}{k}} \cdot \sqrt{n + n} \]
  8. Applied rewrites49.5%

    \[\leadsto \sqrt{\frac{\pi}{k}} \cdot \color{blue}{\sqrt{n + n}} \]
  9. Add Preprocessing

Alternative 6: 37.9% accurate, 2.8× speedup?

\[\sqrt{\left|\frac{\pi + \pi}{k} \cdot n\right|} \]
(FPCore (k n) :precision binary64 (sqrt (fabs (* (/ (+ PI PI) k) n))))
double code(double k, double n) {
	return sqrt(fabs((((((double) M_PI) + ((double) M_PI)) / k) * n)));
}
public static double code(double k, double n) {
	return Math.sqrt(Math.abs((((Math.PI + Math.PI) / k) * n)));
}
def code(k, n):
	return math.sqrt(math.fabs((((math.pi + math.pi) / k) * n)))
function code(k, n)
	return sqrt(abs(Float64(Float64(Float64(pi + pi) / k) * n)))
end
function tmp = code(k, n)
	tmp = sqrt(abs((((pi + pi) / k) * n)));
end
code[k_, n_] := N[Sqrt[N[Abs[N[(N[(N[(Pi + Pi), $MachinePrecision] / k), $MachinePrecision] * n), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]
\sqrt{\left|\frac{\pi + \pi}{k} \cdot n\right|}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
  2. Taylor expanded in k around 0

    \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
  3. Step-by-step derivation
    1. lower-/.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
    2. lower-pow.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
    3. lower-*.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
    4. lower-*.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
    5. lower-PI.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
    6. lower-sqrt.f6449.5

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}} \]
  4. Applied rewrites49.5%

    \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}}} \]
  5. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
    2. lift-pow.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
    3. unpow1/2N/A

      \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{\color{blue}{k}}} \]
    4. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{k}} \]
    5. count-2-revN/A

      \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
    6. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
    7. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
    8. distribute-lft-inN/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    9. lift-+.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    10. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    11. lift-sqrt.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    12. sqrt-undivN/A

      \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
    13. lower-sqrt.f64N/A

      \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
  6. Applied rewrites37.9%

    \[\leadsto \sqrt{\left(n + n\right) \cdot \frac{\pi}{k}} \]
  7. Applied rewrites37.9%

    \[\leadsto \sqrt{\left|\frac{\pi + \pi}{k} \cdot n\right|} \]
  8. Add Preprocessing

Alternative 7: 37.9% accurate, 3.1× speedup?

\[\sqrt{\left(n + n\right) \cdot \frac{\pi}{k}} \]
(FPCore (k n) :precision binary64 (sqrt (* (+ n n) (/ PI k))))
double code(double k, double n) {
	return sqrt(((n + n) * (((double) M_PI) / k)));
}
public static double code(double k, double n) {
	return Math.sqrt(((n + n) * (Math.PI / k)));
}
def code(k, n):
	return math.sqrt(((n + n) * (math.pi / k)))
function code(k, n)
	return sqrt(Float64(Float64(n + n) * Float64(pi / k)))
end
function tmp = code(k, n)
	tmp = sqrt(((n + n) * (pi / k)));
end
code[k_, n_] := N[Sqrt[N[(N[(n + n), $MachinePrecision] * N[(Pi / k), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\sqrt{\left(n + n\right) \cdot \frac{\pi}{k}}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
  2. Taylor expanded in k around 0

    \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
  3. Step-by-step derivation
    1. lower-/.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
    2. lower-pow.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
    3. lower-*.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
    4. lower-*.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
    5. lower-PI.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
    6. lower-sqrt.f6449.5

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}} \]
  4. Applied rewrites49.5%

    \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}}} \]
  5. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
    2. lift-pow.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
    3. unpow1/2N/A

      \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{\color{blue}{k}}} \]
    4. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{k}} \]
    5. count-2-revN/A

      \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
    6. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
    7. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
    8. distribute-lft-inN/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    9. lift-+.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    10. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    11. lift-sqrt.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    12. sqrt-undivN/A

      \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
    13. lower-sqrt.f64N/A

      \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
  6. Applied rewrites37.9%

    \[\leadsto \sqrt{\left(n + n\right) \cdot \frac{\pi}{k}} \]
  7. Add Preprocessing

Alternative 8: 37.9% accurate, 4.0× speedup?

\[\sqrt{6.283185307179586 \cdot \frac{n}{k}} \]
(FPCore (k n) :precision binary64 (sqrt (* 6.283185307179586 (/ n k))))
double code(double k, double n) {
	return sqrt((6.283185307179586 * (n / k)));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(k, n)
use fmin_fmax_functions
    real(8), intent (in) :: k
    real(8), intent (in) :: n
    code = sqrt((6.283185307179586d0 * (n / k)))
end function
public static double code(double k, double n) {
	return Math.sqrt((6.283185307179586 * (n / k)));
}
def code(k, n):
	return math.sqrt((6.283185307179586 * (n / k)))
function code(k, n)
	return sqrt(Float64(6.283185307179586 * Float64(n / k)))
end
function tmp = code(k, n)
	tmp = sqrt((6.283185307179586 * (n / k)));
end
code[k_, n_] := N[Sqrt[N[(6.283185307179586 * N[(n / k), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\sqrt{6.283185307179586 \cdot \frac{n}{k}}
Derivation
  1. Initial program 99.4%

    \[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)} \]
  2. Taylor expanded in k around 0

    \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}}} \]
  3. Step-by-step derivation
    1. lower-/.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
    2. lower-pow.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
    3. lower-*.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
    4. lower-*.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \mathsf{PI}\left(\right)\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
    5. lower-PI.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{k}} \]
    6. lower-sqrt.f6449.5

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}} \]
  4. Applied rewrites49.5%

    \[\leadsto \color{blue}{\frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{0.5}}{\sqrt{k}}} \]
  5. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\color{blue}{\sqrt{k}}} \]
    2. lift-pow.f64N/A

      \[\leadsto \frac{{\left(2 \cdot \left(n \cdot \pi\right)\right)}^{\frac{1}{2}}}{\sqrt{\color{blue}{k}}} \]
    3. unpow1/2N/A

      \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{\color{blue}{k}}} \]
    4. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{2 \cdot \left(n \cdot \pi\right)}}{\sqrt{k}} \]
    5. count-2-revN/A

      \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
    6. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
    7. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \pi + n \cdot \pi}}{\sqrt{k}} \]
    8. distribute-lft-inN/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    9. lift-+.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    10. lift-*.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    11. lift-sqrt.f64N/A

      \[\leadsto \frac{\sqrt{n \cdot \left(\pi + \pi\right)}}{\sqrt{k}} \]
    12. sqrt-undivN/A

      \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
    13. lower-sqrt.f64N/A

      \[\leadsto \sqrt{\frac{n \cdot \left(\pi + \pi\right)}{k}} \]
  6. Applied rewrites37.9%

    \[\leadsto \sqrt{\left(n + n\right) \cdot \frac{\pi}{k}} \]
  7. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \sqrt{\left(n + n\right) \cdot \frac{\pi}{k}} \]
    2. *-commutativeN/A

      \[\leadsto \sqrt{\frac{\pi}{k} \cdot \left(n + n\right)} \]
    3. lift-+.f64N/A

      \[\leadsto \sqrt{\frac{\pi}{k} \cdot \left(n + n\right)} \]
    4. distribute-lft-inN/A

      \[\leadsto \sqrt{\frac{\pi}{k} \cdot n + \frac{\pi}{k} \cdot n} \]
    5. count-2N/A

      \[\leadsto \sqrt{2 \cdot \left(\frac{\pi}{k} \cdot n\right)} \]
    6. lift-/.f64N/A

      \[\leadsto \sqrt{2 \cdot \left(\frac{\pi}{k} \cdot n\right)} \]
    7. associate-*l/N/A

      \[\leadsto \sqrt{2 \cdot \frac{\pi \cdot n}{k}} \]
    8. associate-/l*N/A

      \[\leadsto \sqrt{2 \cdot \left(\pi \cdot \frac{n}{k}\right)} \]
    9. associate-*l*N/A

      \[\leadsto \sqrt{\left(2 \cdot \pi\right) \cdot \frac{n}{k}} \]
    10. lift-PI.f64N/A

      \[\leadsto \sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{n}{k}} \]
    11. lower-*.f64N/A

      \[\leadsto \sqrt{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \frac{n}{k}} \]
    12. lift-PI.f64N/A

      \[\leadsto \sqrt{\left(2 \cdot \pi\right) \cdot \frac{n}{k}} \]
    13. count-2-revN/A

      \[\leadsto \sqrt{\left(\pi + \pi\right) \cdot \frac{n}{k}} \]
    14. lower-+.f64N/A

      \[\leadsto \sqrt{\left(\pi + \pi\right) \cdot \frac{n}{k}} \]
    15. lower-/.f6437.9

      \[\leadsto \sqrt{\left(\pi + \pi\right) \cdot \frac{n}{k}} \]
  8. Applied rewrites37.9%

    \[\leadsto \sqrt{\left(\pi + \pi\right) \cdot \frac{n}{k}} \]
  9. Evaluated real constant37.9%

    \[\leadsto \sqrt{\frac{884279719003555}{140737488355328} \cdot \frac{n}{k}} \]
  10. Add Preprocessing

Reproduce

?
herbie shell --seed 2025175 
(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))))