2-ancestry mixing, positive discriminant

Percentage Accurate: 44.2% → 95.5%
Time: 7.0s
Alternatives: 3
Speedup: 3.9×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{2 \cdot a}\\ t_1 := \sqrt{g \cdot g - h \cdot h}\\ \sqrt[3]{t\_0 \cdot \left(\left(-g\right) + t\_1\right)} + \sqrt[3]{t\_0 \cdot \left(\left(-g\right) - t\_1\right)} \end{array} \end{array} \]
(FPCore (g h a)
 :precision binary64
 (let* ((t_0 (/ 1.0 (* 2.0 a))) (t_1 (sqrt (- (* g g) (* h h)))))
   (+ (cbrt (* t_0 (+ (- g) t_1))) (cbrt (* t_0 (- (- g) t_1))))))
double code(double g, double h, double a) {
	double t_0 = 1.0 / (2.0 * a);
	double t_1 = sqrt(((g * g) - (h * h)));
	return cbrt((t_0 * (-g + t_1))) + cbrt((t_0 * (-g - t_1)));
}
public static double code(double g, double h, double a) {
	double t_0 = 1.0 / (2.0 * a);
	double t_1 = Math.sqrt(((g * g) - (h * h)));
	return Math.cbrt((t_0 * (-g + t_1))) + Math.cbrt((t_0 * (-g - t_1)));
}
function code(g, h, a)
	t_0 = Float64(1.0 / Float64(2.0 * a))
	t_1 = sqrt(Float64(Float64(g * g) - Float64(h * h)))
	return Float64(cbrt(Float64(t_0 * Float64(Float64(-g) + t_1))) + cbrt(Float64(t_0 * Float64(Float64(-g) - t_1))))
end
code[g_, h_, a_] := Block[{t$95$0 = N[(1.0 / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[Sqrt[N[(N[(g * g), $MachinePrecision] - N[(h * h), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, N[(N[Power[N[(t$95$0 * N[((-g) + t$95$1), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision] + N[Power[N[(t$95$0 * N[((-g) - t$95$1), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1}{2 \cdot a}\\
t_1 := \sqrt{g \cdot g - h \cdot h}\\
\sqrt[3]{t\_0 \cdot \left(\left(-g\right) + t\_1\right)} + \sqrt[3]{t\_0 \cdot \left(\left(-g\right) - t\_1\right)}
\end{array}
\end{array}

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 3 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: 44.2% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{2 \cdot a}\\ t_1 := \sqrt{g \cdot g - h \cdot h}\\ \sqrt[3]{t\_0 \cdot \left(\left(-g\right) + t\_1\right)} + \sqrt[3]{t\_0 \cdot \left(\left(-g\right) - t\_1\right)} \end{array} \end{array} \]
(FPCore (g h a)
 :precision binary64
 (let* ((t_0 (/ 1.0 (* 2.0 a))) (t_1 (sqrt (- (* g g) (* h h)))))
   (+ (cbrt (* t_0 (+ (- g) t_1))) (cbrt (* t_0 (- (- g) t_1))))))
double code(double g, double h, double a) {
	double t_0 = 1.0 / (2.0 * a);
	double t_1 = sqrt(((g * g) - (h * h)));
	return cbrt((t_0 * (-g + t_1))) + cbrt((t_0 * (-g - t_1)));
}
public static double code(double g, double h, double a) {
	double t_0 = 1.0 / (2.0 * a);
	double t_1 = Math.sqrt(((g * g) - (h * h)));
	return Math.cbrt((t_0 * (-g + t_1))) + Math.cbrt((t_0 * (-g - t_1)));
}
function code(g, h, a)
	t_0 = Float64(1.0 / Float64(2.0 * a))
	t_1 = sqrt(Float64(Float64(g * g) - Float64(h * h)))
	return Float64(cbrt(Float64(t_0 * Float64(Float64(-g) + t_1))) + cbrt(Float64(t_0 * Float64(Float64(-g) - t_1))))
end
code[g_, h_, a_] := Block[{t$95$0 = N[(1.0 / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[Sqrt[N[(N[(g * g), $MachinePrecision] - N[(h * h), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, N[(N[Power[N[(t$95$0 * N[((-g) + t$95$1), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision] + N[Power[N[(t$95$0 * N[((-g) - t$95$1), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1}{2 \cdot a}\\
t_1 := \sqrt{g \cdot g - h \cdot h}\\
\sqrt[3]{t\_0 \cdot \left(\left(-g\right) + t\_1\right)} + \sqrt[3]{t\_0 \cdot \left(\left(-g\right) - t\_1\right)}
\end{array}
\end{array}

Alternative 1: 95.5% accurate, 2.1× speedup?

\[\begin{array}{l} \\ -\frac{\sqrt[3]{g}}{\sqrt[3]{a}} \cdot 1 \end{array} \]
(FPCore (g h a) :precision binary64 (- (* (/ (cbrt g) (cbrt a)) 1.0)))
double code(double g, double h, double a) {
	return -((cbrt(g) / cbrt(a)) * 1.0);
}
public static double code(double g, double h, double a) {
	return -((Math.cbrt(g) / Math.cbrt(a)) * 1.0);
}
function code(g, h, a)
	return Float64(-Float64(Float64(cbrt(g) / cbrt(a)) * 1.0))
end
code[g_, h_, a_] := (-N[(N[(N[Power[g, 1/3], $MachinePrecision] / N[Power[a, 1/3], $MachinePrecision]), $MachinePrecision] * 1.0), $MachinePrecision])
\begin{array}{l}

\\
-\frac{\sqrt[3]{g}}{\sqrt[3]{a}} \cdot 1
\end{array}
Derivation
  1. Initial program 44.2%

    \[\sqrt[3]{\frac{1}{2 \cdot a} \cdot \left(\left(-g\right) + \sqrt{g \cdot g - h \cdot h}\right)} + \sqrt[3]{\frac{1}{2 \cdot a} \cdot \left(\left(-g\right) - \sqrt{g \cdot g - h \cdot h}\right)} \]
  2. Taylor expanded in g around -inf

    \[\leadsto \color{blue}{-1 \cdot \left(\sqrt[3]{\frac{g}{a}} \cdot \left(\sqrt[3]{\frac{1}{2}} \cdot \sqrt[3]{2}\right)\right)} \]
  3. Step-by-step derivation
    1. mul-1-negN/A

      \[\leadsto \mathsf{neg}\left(\sqrt[3]{\frac{g}{a}} \cdot \left(\sqrt[3]{\frac{1}{2}} \cdot \sqrt[3]{2}\right)\right) \]
    2. lower-neg.f64N/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot \left(\sqrt[3]{\frac{1}{2}} \cdot \sqrt[3]{2}\right) \]
    3. cbrt-unprodN/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot \sqrt[3]{\frac{1}{2} \cdot 2} \]
    4. metadata-evalN/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot \sqrt[3]{1} \]
    5. metadata-evalN/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot 1 \]
    6. lower-*.f64N/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot 1 \]
    7. lower-cbrt.f64N/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot 1 \]
    8. lower-/.f6474.3

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot 1 \]
  4. Applied rewrites74.3%

    \[\leadsto \color{blue}{-\sqrt[3]{\frac{g}{a}} \cdot 1} \]
  5. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot 1 \]
    2. lift-cbrt.f64N/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot 1 \]
    3. cbrt-divN/A

      \[\leadsto -\frac{\sqrt[3]{g}}{\sqrt[3]{a}} \cdot 1 \]
    4. lower-/.f64N/A

      \[\leadsto -\frac{\sqrt[3]{g}}{\sqrt[3]{a}} \cdot 1 \]
    5. lower-cbrt.f64N/A

      \[\leadsto -\frac{\sqrt[3]{g}}{\sqrt[3]{a}} \cdot 1 \]
    6. lower-cbrt.f6495.5

      \[\leadsto -\frac{\sqrt[3]{g}}{\sqrt[3]{a}} \cdot 1 \]
  6. Applied rewrites95.5%

    \[\leadsto -\frac{\sqrt[3]{g}}{\sqrt[3]{a}} \cdot 1 \]
  7. Add Preprocessing

Alternative 2: 74.4% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{1}{2 \cdot a} \leq 10^{+230}:\\ \;\;\;\;-\sqrt[3]{\frac{g}{a}}\\ \mathbf{else}:\\ \;\;\;\;-1 \cdot \left(g \cdot \sqrt[3]{\frac{1}{a \cdot \left(g \cdot g\right)}}\right)\\ \end{array} \end{array} \]
(FPCore (g h a)
 :precision binary64
 (if (<= (/ 1.0 (* 2.0 a)) 1e+230)
   (- (cbrt (/ g a)))
   (* -1.0 (* g (cbrt (/ 1.0 (* a (* g g))))))))
double code(double g, double h, double a) {
	double tmp;
	if ((1.0 / (2.0 * a)) <= 1e+230) {
		tmp = -cbrt((g / a));
	} else {
		tmp = -1.0 * (g * cbrt((1.0 / (a * (g * g)))));
	}
	return tmp;
}
public static double code(double g, double h, double a) {
	double tmp;
	if ((1.0 / (2.0 * a)) <= 1e+230) {
		tmp = -Math.cbrt((g / a));
	} else {
		tmp = -1.0 * (g * Math.cbrt((1.0 / (a * (g * g)))));
	}
	return tmp;
}
function code(g, h, a)
	tmp = 0.0
	if (Float64(1.0 / Float64(2.0 * a)) <= 1e+230)
		tmp = Float64(-cbrt(Float64(g / a)));
	else
		tmp = Float64(-1.0 * Float64(g * cbrt(Float64(1.0 / Float64(a * Float64(g * g))))));
	end
	return tmp
end
code[g_, h_, a_] := If[LessEqual[N[(1.0 / N[(2.0 * a), $MachinePrecision]), $MachinePrecision], 1e+230], (-N[Power[N[(g / a), $MachinePrecision], 1/3], $MachinePrecision]), N[(-1.0 * N[(g * N[Power[N[(1.0 / N[(a * N[(g * g), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{1}{2 \cdot a} \leq 10^{+230}:\\
\;\;\;\;-\sqrt[3]{\frac{g}{a}}\\

\mathbf{else}:\\
\;\;\;\;-1 \cdot \left(g \cdot \sqrt[3]{\frac{1}{a \cdot \left(g \cdot g\right)}}\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 #s(literal 1 binary64) (*.f64 #s(literal 2 binary64) a)) < 1.0000000000000001e230

    1. Initial program 45.2%

      \[\sqrt[3]{\frac{1}{2 \cdot a} \cdot \left(\left(-g\right) + \sqrt{g \cdot g - h \cdot h}\right)} + \sqrt[3]{\frac{1}{2 \cdot a} \cdot \left(\left(-g\right) - \sqrt{g \cdot g - h \cdot h}\right)} \]
    2. Taylor expanded in g around -inf

      \[\leadsto \color{blue}{-1 \cdot \left(\sqrt[3]{\frac{g}{a}} \cdot \left(\sqrt[3]{\frac{1}{2}} \cdot \sqrt[3]{2}\right)\right)} \]
    3. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto \mathsf{neg}\left(\sqrt[3]{\frac{g}{a}} \cdot \left(\sqrt[3]{\frac{1}{2}} \cdot \sqrt[3]{2}\right)\right) \]
      2. lower-neg.f64N/A

        \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot \left(\sqrt[3]{\frac{1}{2}} \cdot \sqrt[3]{2}\right) \]
      3. cbrt-unprodN/A

        \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot \sqrt[3]{\frac{1}{2} \cdot 2} \]
      4. metadata-evalN/A

        \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot \sqrt[3]{1} \]
      5. metadata-evalN/A

        \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot 1 \]
      6. lower-*.f64N/A

        \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot 1 \]
      7. lower-cbrt.f64N/A

        \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot 1 \]
      8. lower-/.f6477.0

        \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot 1 \]
    4. Applied rewrites77.0%

      \[\leadsto \color{blue}{-\sqrt[3]{\frac{g}{a}} \cdot 1} \]
    5. Taylor expanded in g around 0

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \]
    6. Step-by-step derivation
      1. lift-cbrt.f64N/A

        \[\leadsto -\sqrt[3]{\frac{g}{a}} \]
      2. lift-/.f6477.0

        \[\leadsto -\sqrt[3]{\frac{g}{a}} \]
    7. Applied rewrites77.0%

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \]

    if 1.0000000000000001e230 < (/.f64 #s(literal 1 binary64) (*.f64 #s(literal 2 binary64) a))

    1. Initial program 28.1%

      \[\sqrt[3]{\frac{1}{2 \cdot a} \cdot \left(\left(-g\right) + \sqrt{g \cdot g - h \cdot h}\right)} + \sqrt[3]{\frac{1}{2 \cdot a} \cdot \left(\left(-g\right) - \sqrt{g \cdot g - h \cdot h}\right)} \]
    2. Taylor expanded in a around inf

      \[\leadsto \color{blue}{\sqrt[3]{\frac{g + \sqrt{{g}^{2} - {h}^{2}}}{a}} \cdot \sqrt[3]{\frac{-1}{2}} + \sqrt[3]{\frac{\sqrt{{g}^{2} - {h}^{2}} - g}{a}} \cdot \sqrt[3]{\frac{1}{2}}} \]
    3. Applied rewrites28.1%

      \[\leadsto \color{blue}{\sqrt[3]{\frac{\sqrt{\left(g + h\right) \cdot \left(g - h\right)} + g}{a} \cdot -0.5} + \sqrt[3]{\frac{\sqrt{\left(g + h\right) \cdot \left(g - h\right)} - g}{a} \cdot 0.5}} \]
    4. Taylor expanded in g around -inf

      \[\leadsto -1 \cdot \color{blue}{\left(g \cdot \left(\sqrt[3]{\frac{1 + {\left(\sqrt{-1}\right)}^{2}}{a \cdot {g}^{2}}} \cdot \sqrt[3]{\frac{1}{2}} + \sqrt[3]{\frac{{\left(\sqrt{-1}\right)}^{2} - 1}{a \cdot {g}^{2}}} \cdot \sqrt[3]{\frac{-1}{2}}\right)\right)} \]
    5. Step-by-step derivation
      1. lower-*.f64N/A

        \[\leadsto -1 \cdot \left(g \cdot \color{blue}{\left(\sqrt[3]{\frac{1 + {\left(\sqrt{-1}\right)}^{2}}{a \cdot {g}^{2}}} \cdot \sqrt[3]{\frac{1}{2}} + \sqrt[3]{\frac{{\left(\sqrt{-1}\right)}^{2} - 1}{a \cdot {g}^{2}}} \cdot \sqrt[3]{\frac{-1}{2}}\right)}\right) \]
      2. lower-*.f64N/A

        \[\leadsto -1 \cdot \left(g \cdot \left(\sqrt[3]{\frac{1 + {\left(\sqrt{-1}\right)}^{2}}{a \cdot {g}^{2}}} \cdot \sqrt[3]{\frac{1}{2}} + \color{blue}{\sqrt[3]{\frac{{\left(\sqrt{-1}\right)}^{2} - 1}{a \cdot {g}^{2}}} \cdot \sqrt[3]{\frac{-1}{2}}}\right)\right) \]
      3. lower-+.f64N/A

        \[\leadsto -1 \cdot \left(g \cdot \left(\sqrt[3]{\frac{1 + {\left(\sqrt{-1}\right)}^{2}}{a \cdot {g}^{2}}} \cdot \sqrt[3]{\frac{1}{2}} + \sqrt[3]{\frac{{\left(\sqrt{-1}\right)}^{2} - 1}{a \cdot {g}^{2}}} \cdot \color{blue}{\sqrt[3]{\frac{-1}{2}}}\right)\right) \]
    6. Applied rewrites33.8%

      \[\leadsto -1 \cdot \color{blue}{\left(g \cdot \left(\sqrt[3]{\frac{0}{a \cdot \left(g \cdot g\right)} \cdot 0.5} + \sqrt[3]{\frac{-2}{a \cdot \left(g \cdot g\right)} \cdot -0.5}\right)\right)} \]
    7. Taylor expanded in g around 0

      \[\leadsto -1 \cdot \left(g \cdot \sqrt[3]{\frac{1}{a \cdot {g}^{2}}}\right) \]
    8. Step-by-step derivation
      1. lower-cbrt.f64N/A

        \[\leadsto -1 \cdot \left(g \cdot \sqrt[3]{\frac{1}{a \cdot {g}^{2}}}\right) \]
      2. lower-/.f64N/A

        \[\leadsto -1 \cdot \left(g \cdot \sqrt[3]{\frac{1}{a \cdot {g}^{2}}}\right) \]
      3. pow2N/A

        \[\leadsto -1 \cdot \left(g \cdot \sqrt[3]{\frac{1}{a \cdot \left(g \cdot g\right)}}\right) \]
      4. lift-*.f64N/A

        \[\leadsto -1 \cdot \left(g \cdot \sqrt[3]{\frac{1}{a \cdot \left(g \cdot g\right)}}\right) \]
      5. lift-*.f6434.6

        \[\leadsto -1 \cdot \left(g \cdot \sqrt[3]{\frac{1}{a \cdot \left(g \cdot g\right)}}\right) \]
    9. Applied rewrites34.6%

      \[\leadsto -1 \cdot \left(g \cdot \sqrt[3]{\frac{1}{a \cdot \left(g \cdot g\right)}}\right) \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 74.3% accurate, 3.9× speedup?

\[\begin{array}{l} \\ -\sqrt[3]{\frac{g}{a}} \end{array} \]
(FPCore (g h a) :precision binary64 (- (cbrt (/ g a))))
double code(double g, double h, double a) {
	return -cbrt((g / a));
}
public static double code(double g, double h, double a) {
	return -Math.cbrt((g / a));
}
function code(g, h, a)
	return Float64(-cbrt(Float64(g / a)))
end
code[g_, h_, a_] := (-N[Power[N[(g / a), $MachinePrecision], 1/3], $MachinePrecision])
\begin{array}{l}

\\
-\sqrt[3]{\frac{g}{a}}
\end{array}
Derivation
  1. Initial program 44.2%

    \[\sqrt[3]{\frac{1}{2 \cdot a} \cdot \left(\left(-g\right) + \sqrt{g \cdot g - h \cdot h}\right)} + \sqrt[3]{\frac{1}{2 \cdot a} \cdot \left(\left(-g\right) - \sqrt{g \cdot g - h \cdot h}\right)} \]
  2. Taylor expanded in g around -inf

    \[\leadsto \color{blue}{-1 \cdot \left(\sqrt[3]{\frac{g}{a}} \cdot \left(\sqrt[3]{\frac{1}{2}} \cdot \sqrt[3]{2}\right)\right)} \]
  3. Step-by-step derivation
    1. mul-1-negN/A

      \[\leadsto \mathsf{neg}\left(\sqrt[3]{\frac{g}{a}} \cdot \left(\sqrt[3]{\frac{1}{2}} \cdot \sqrt[3]{2}\right)\right) \]
    2. lower-neg.f64N/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot \left(\sqrt[3]{\frac{1}{2}} \cdot \sqrt[3]{2}\right) \]
    3. cbrt-unprodN/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot \sqrt[3]{\frac{1}{2} \cdot 2} \]
    4. metadata-evalN/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot \sqrt[3]{1} \]
    5. metadata-evalN/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot 1 \]
    6. lower-*.f64N/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot 1 \]
    7. lower-cbrt.f64N/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot 1 \]
    8. lower-/.f6474.3

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \cdot 1 \]
  4. Applied rewrites74.3%

    \[\leadsto \color{blue}{-\sqrt[3]{\frac{g}{a}} \cdot 1} \]
  5. Taylor expanded in g around 0

    \[\leadsto -\sqrt[3]{\frac{g}{a}} \]
  6. Step-by-step derivation
    1. lift-cbrt.f64N/A

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \]
    2. lift-/.f6474.3

      \[\leadsto -\sqrt[3]{\frac{g}{a}} \]
  7. Applied rewrites74.3%

    \[\leadsto -\sqrt[3]{\frac{g}{a}} \]
  8. Add Preprocessing

Reproduce

?
herbie shell --seed 2025117 
(FPCore (g h a)
  :name "2-ancestry mixing, positive discriminant"
  :precision binary64
  (+ (cbrt (* (/ 1.0 (* 2.0 a)) (+ (- g) (sqrt (- (* g g) (* h h)))))) (cbrt (* (/ 1.0 (* 2.0 a)) (- (- g) (sqrt (- (* g g) (* h h))))))))