2-ancestry mixing, negative discriminant

Percentage Accurate: 98.5% → 100.0%
Time: 2.9s
Alternatives: 2
Speedup: 1.1×

Specification

?
\[\begin{array}{l} \\ 2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \end{array} \]
(FPCore (g h)
 :precision binary64
 (* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))
double code(double g, double h) {
	return 2.0 * cos((((2.0 * ((double) M_PI)) / 3.0) + (acos((-g / h)) / 3.0)));
}
public static double code(double g, double h) {
	return 2.0 * Math.cos((((2.0 * Math.PI) / 3.0) + (Math.acos((-g / h)) / 3.0)));
}
def code(g, h):
	return 2.0 * math.cos((((2.0 * math.pi) / 3.0) + (math.acos((-g / h)) / 3.0)))
function code(g, h)
	return Float64(2.0 * cos(Float64(Float64(Float64(2.0 * pi) / 3.0) + Float64(acos(Float64(Float64(-g) / h)) / 3.0))))
end
function tmp = code(g, h)
	tmp = 2.0 * cos((((2.0 * pi) / 3.0) + (acos((-g / h)) / 3.0)));
end
code[g_, h_] := N[(2.0 * N[Cos[N[(N[(N[(2.0 * Pi), $MachinePrecision] / 3.0), $MachinePrecision] + N[(N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision] / 3.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)
\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 2 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: 98.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ 2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \end{array} \]
(FPCore (g h)
 :precision binary64
 (* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))
double code(double g, double h) {
	return 2.0 * cos((((2.0 * ((double) M_PI)) / 3.0) + (acos((-g / h)) / 3.0)));
}
public static double code(double g, double h) {
	return 2.0 * Math.cos((((2.0 * Math.PI) / 3.0) + (Math.acos((-g / h)) / 3.0)));
}
def code(g, h):
	return 2.0 * math.cos((((2.0 * math.pi) / 3.0) + (math.acos((-g / h)) / 3.0)))
function code(g, h)
	return Float64(2.0 * cos(Float64(Float64(Float64(2.0 * pi) / 3.0) + Float64(acos(Float64(Float64(-g) / h)) / 3.0))))
end
function tmp = code(g, h)
	tmp = 2.0 * cos((((2.0 * pi) / 3.0) + (acos((-g / h)) / 3.0)));
end
code[g_, h_] := N[(2.0 * N[Cos[N[(N[(N[(2.0 * Pi), $MachinePrecision] / 3.0), $MachinePrecision] + N[(N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision] / 3.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)
\end{array}

Alternative 1: 100.0% accurate, 1.1× speedup?

\[\begin{array}{l} \\ 2 \cdot \sin \left(\mathsf{fma}\left(\pi, -0.16666666666666666, -0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right)\right) \end{array} \]
(FPCore (g h)
 :precision binary64
 (*
  2.0
  (sin
   (fma PI -0.16666666666666666 (* -0.3333333333333333 (acos (/ (- g) h)))))))
double code(double g, double h) {
	return 2.0 * sin(fma(((double) M_PI), -0.16666666666666666, (-0.3333333333333333 * acos((-g / h)))));
}
function code(g, h)
	return Float64(2.0 * sin(fma(pi, -0.16666666666666666, Float64(-0.3333333333333333 * acos(Float64(Float64(-g) / h))))))
end
code[g_, h_] := N[(2.0 * N[Sin[N[(Pi * -0.16666666666666666 + N[(-0.3333333333333333 * N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
2 \cdot \sin \left(\mathsf{fma}\left(\pi, -0.16666666666666666, -0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right)\right)
\end{array}
Derivation
  1. Initial program 98.5%

    \[2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
  2. Step-by-step derivation
    1. lift-cos.f64N/A

      \[\leadsto 2 \cdot \color{blue}{\cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)} \]
    2. cos-neg-revN/A

      \[\leadsto 2 \cdot \color{blue}{\cos \left(\mathsf{neg}\left(\left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)\right)} \]
    3. sin-+PI/2-revN/A

      \[\leadsto 2 \cdot \color{blue}{\sin \left(\left(\mathsf{neg}\left(\left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right)} \]
    4. lower-sin.f64N/A

      \[\leadsto 2 \cdot \color{blue}{\sin \left(\left(\mathsf{neg}\left(\left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right)} \]
    5. lower-+.f64N/A

      \[\leadsto 2 \cdot \sin \color{blue}{\left(\left(\mathsf{neg}\left(\left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right)} \]
  3. Applied rewrites98.5%

    \[\leadsto 2 \cdot \color{blue}{\sin \left(\frac{\mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right)}{-3} + \frac{\pi}{2}\right)} \]
  4. Taylor expanded in g around 0

    \[\leadsto 2 \cdot \sin \color{blue}{\left(\frac{-1}{3} \cdot \left(\cos^{-1} \left(-1 \cdot \frac{g}{h}\right) + 2 \cdot \mathsf{PI}\left(\right)\right) + \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right)} \]
  5. Step-by-step derivation
    1. Applied rewrites99.9%

      \[\leadsto 2 \cdot \sin \color{blue}{\left(\mathsf{fma}\left(-0.3333333333333333, \cos^{-1} \left(\frac{-g}{h}\right), \mathsf{fma}\left(\pi, -0.6666666666666666, 0.5 \cdot \pi\right)\right)\right)} \]
    2. Step-by-step derivation
      1. lift-fma.f64N/A

        \[\leadsto 2 \cdot \sin \left(\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right) + \color{blue}{\mathsf{fma}\left(\pi, \frac{-2}{3}, \frac{1}{2} \cdot \pi\right)}\right) \]
      2. +-commutativeN/A

        \[\leadsto 2 \cdot \sin \left(\mathsf{fma}\left(\pi, \frac{-2}{3}, \frac{1}{2} \cdot \pi\right) + \color{blue}{\frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)}\right) \]
      3. lift-PI.f64N/A

        \[\leadsto 2 \cdot \sin \left(\mathsf{fma}\left(\mathsf{PI}\left(\right), \frac{-2}{3}, \frac{1}{2} \cdot \pi\right) + \frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
      4. lift-fma.f64N/A

        \[\leadsto 2 \cdot \sin \left(\left(\mathsf{PI}\left(\right) \cdot \frac{-2}{3} + \frac{1}{2} \cdot \pi\right) + \color{blue}{\frac{-1}{3}} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
      5. lift-PI.f64N/A

        \[\leadsto 2 \cdot \sin \left(\left(\mathsf{PI}\left(\right) \cdot \frac{-2}{3} + \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right) + \frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
      6. lift-*.f64N/A

        \[\leadsto 2 \cdot \sin \left(\left(\mathsf{PI}\left(\right) \cdot \frac{-2}{3} + \frac{1}{2} \cdot \mathsf{PI}\left(\right)\right) + \frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
      7. *-commutativeN/A

        \[\leadsto 2 \cdot \sin \left(\left(\mathsf{PI}\left(\right) \cdot \frac{-2}{3} + \mathsf{PI}\left(\right) \cdot \frac{1}{2}\right) + \frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
      8. distribute-lft-outN/A

        \[\leadsto 2 \cdot \sin \left(\mathsf{PI}\left(\right) \cdot \left(\frac{-2}{3} + \frac{1}{2}\right) + \color{blue}{\frac{-1}{3}} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
      9. metadata-evalN/A

        \[\leadsto 2 \cdot \sin \left(\mathsf{PI}\left(\right) \cdot \frac{-1}{6} + \frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
      10. lift-acos.f64N/A

        \[\leadsto 2 \cdot \sin \left(\mathsf{PI}\left(\right) \cdot \frac{-1}{6} + \frac{-1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
      11. lift-neg.f64N/A

        \[\leadsto 2 \cdot \sin \left(\mathsf{PI}\left(\right) \cdot \frac{-1}{6} + \frac{-1}{3} \cdot \cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right)\right) \]
      12. lift-/.f64N/A

        \[\leadsto 2 \cdot \sin \left(\mathsf{PI}\left(\right) \cdot \frac{-1}{6} + \frac{-1}{3} \cdot \cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right)\right) \]
      13. acos-asinN/A

        \[\leadsto 2 \cdot \sin \left(\mathsf{PI}\left(\right) \cdot \frac{-1}{6} + \frac{-1}{3} \cdot \left(\frac{\mathsf{PI}\left(\right)}{2} - \color{blue}{\sin^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right)}\right)\right) \]
      14. distribute-frac-negN/A

        \[\leadsto 2 \cdot \sin \left(\mathsf{PI}\left(\right) \cdot \frac{-1}{6} + \frac{-1}{3} \cdot \left(\frac{\mathsf{PI}\left(\right)}{2} - \sin^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right)\right)\right) \]
      15. mul-1-negN/A

        \[\leadsto 2 \cdot \sin \left(\mathsf{PI}\left(\right) \cdot \frac{-1}{6} + \frac{-1}{3} \cdot \left(\frac{\mathsf{PI}\left(\right)}{2} - \sin^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)\right) \]
      16. acos-asinN/A

        \[\leadsto 2 \cdot \sin \left(\mathsf{PI}\left(\right) \cdot \frac{-1}{6} + \frac{-1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right) \]
      17. lower-fma.f64N/A

        \[\leadsto 2 \cdot \sin \left(\mathsf{fma}\left(\mathsf{PI}\left(\right), \color{blue}{\frac{-1}{6}}, \frac{-1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)\right) \]
      18. lift-PI.f64N/A

        \[\leadsto 2 \cdot \sin \left(\mathsf{fma}\left(\pi, \frac{-1}{6}, \frac{-1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right)\right)\right) \]
    3. Applied rewrites100.0%

      \[\leadsto 2 \cdot \sin \left(\mathsf{fma}\left(\pi, \color{blue}{-0.16666666666666666}, -0.3333333333333333 \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right)\right) \]
    4. Add Preprocessing

    Alternative 2: 98.5% accurate, 1.1× speedup?

    \[\begin{array}{l} \\ 2 \cdot \cos \left(\mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot 0.3333333333333333\right) \end{array} \]
    (FPCore (g h)
     :precision binary64
     (* 2.0 (cos (* (fma PI 2.0 (acos (/ (- g) h))) 0.3333333333333333))))
    double code(double g, double h) {
    	return 2.0 * cos((fma(((double) M_PI), 2.0, acos((-g / h))) * 0.3333333333333333));
    }
    
    function code(g, h)
    	return Float64(2.0 * cos(Float64(fma(pi, 2.0, acos(Float64(Float64(-g) / h))) * 0.3333333333333333)))
    end
    
    code[g_, h_] := N[(2.0 * N[Cos[N[(N[(Pi * 2.0 + N[ArcCos[N[((-g) / h), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    2 \cdot \cos \left(\mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot 0.3333333333333333\right)
    \end{array}
    
    Derivation
    1. Initial program 98.5%

      \[2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right) \]
    2. Taylor expanded in g around 0

      \[\leadsto 2 \cdot \cos \color{blue}{\left(\frac{1}{3} \cdot \cos^{-1} \left(-1 \cdot \frac{g}{h}\right) + \frac{2}{3} \cdot \mathsf{PI}\left(\right)\right)} \]
    3. Step-by-step derivation
      1. mul-1-negN/A

        \[\leadsto 2 \cdot \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(\mathsf{neg}\left(\frac{g}{h}\right)\right) + \frac{2}{3} \cdot \mathsf{PI}\left(\right)\right) \]
      2. distribute-frac-negN/A

        \[\leadsto 2 \cdot \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right) + \frac{2}{3} \cdot \mathsf{PI}\left(\right)\right) \]
      3. lower-fma.f64N/A

        \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\frac{1}{3}, \color{blue}{\cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right)}, \frac{2}{3} \cdot \mathsf{PI}\left(\right)\right)\right) \]
      4. lift-/.f64N/A

        \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\frac{1}{3}, \cos^{-1} \left(\frac{\mathsf{neg}\left(g\right)}{h}\right), \frac{2}{3} \cdot \mathsf{PI}\left(\right)\right)\right) \]
      5. lift-neg.f64N/A

        \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\frac{1}{3}, \cos^{-1} \left(\frac{-g}{h}\right), \frac{2}{3} \cdot \mathsf{PI}\left(\right)\right)\right) \]
      6. lift-acos.f64N/A

        \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\frac{1}{3}, \cos^{-1} \left(\frac{-g}{h}\right), \frac{2}{3} \cdot \mathsf{PI}\left(\right)\right)\right) \]
      7. lower-*.f64N/A

        \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\frac{1}{3}, \cos^{-1} \left(\frac{-g}{h}\right), \frac{2}{3} \cdot \mathsf{PI}\left(\right)\right)\right) \]
      8. lift-PI.f6498.4

        \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(0.3333333333333333, \cos^{-1} \left(\frac{-g}{h}\right), 0.6666666666666666 \cdot \pi\right)\right) \]
    4. Applied rewrites98.4%

      \[\leadsto 2 \cdot \cos \color{blue}{\left(\mathsf{fma}\left(0.3333333333333333, \cos^{-1} \left(\frac{-g}{h}\right), 0.6666666666666666 \cdot \pi\right)\right)} \]
    5. Step-by-step derivation
      1. lift-fma.f64N/A

        \[\leadsto 2 \cdot \cos \left(\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right) + \color{blue}{\frac{2}{3} \cdot \pi}\right) \]
      2. +-commutativeN/A

        \[\leadsto 2 \cdot \cos \left(\frac{2}{3} \cdot \pi + \color{blue}{\frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)}\right) \]
      3. lift-PI.f64N/A

        \[\leadsto 2 \cdot \cos \left(\frac{2}{3} \cdot \mathsf{PI}\left(\right) + \frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
      4. lift-*.f64N/A

        \[\leadsto 2 \cdot \cos \left(\frac{2}{3} \cdot \mathsf{PI}\left(\right) + \color{blue}{\frac{1}{3}} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
      5. metadata-evalN/A

        \[\leadsto 2 \cdot \cos \left(\left(\frac{1}{3} \cdot 2\right) \cdot \mathsf{PI}\left(\right) + \frac{1}{3} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
      6. associate-*r*N/A

        \[\leadsto 2 \cdot \cos \left(\frac{1}{3} \cdot \left(2 \cdot \mathsf{PI}\left(\right)\right) + \color{blue}{\frac{1}{3}} \cdot \cos^{-1} \left(\frac{-g}{h}\right)\right) \]
      7. distribute-lft-inN/A

        \[\leadsto 2 \cdot \cos \left(\frac{1}{3} \cdot \color{blue}{\left(2 \cdot \mathsf{PI}\left(\right) + \cos^{-1} \left(\frac{-g}{h}\right)\right)}\right) \]
      8. *-commutativeN/A

        \[\leadsto 2 \cdot \cos \left(\frac{1}{3} \cdot \left(\mathsf{PI}\left(\right) \cdot 2 + \cos^{-1} \color{blue}{\left(\frac{-g}{h}\right)}\right)\right) \]
      9. lift-fma.f64N/A

        \[\leadsto 2 \cdot \cos \left(\frac{1}{3} \cdot \mathsf{fma}\left(\mathsf{PI}\left(\right), \color{blue}{2}, \cos^{-1} \left(\frac{-g}{h}\right)\right)\right) \]
      10. lift-PI.f64N/A

        \[\leadsto 2 \cdot \cos \left(\frac{1}{3} \cdot \mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right)\right) \]
      11. *-commutativeN/A

        \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \color{blue}{\frac{1}{3}}\right) \]
      12. lower-*.f6498.5

        \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \color{blue}{0.3333333333333333}\right) \]
    6. Applied rewrites98.5%

      \[\leadsto 2 \cdot \cos \left(\mathsf{fma}\left(\pi, 2, \cos^{-1} \left(\frac{-g}{h}\right)\right) \cdot \color{blue}{0.3333333333333333}\right) \]
    7. Add Preprocessing

    Reproduce

    ?
    herbie shell --seed 2025107 
    (FPCore (g h)
      :name "2-ancestry mixing, negative discriminant"
      :precision binary64
      (* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))