\frac{1}{3} \cdot \cos^{-1} \left(\frac{3 \cdot \frac{x}{y \cdot 27}}{z \cdot 2} \cdot \sqrt{t}\right)\frac{1}{\sqrt[3]{3} \cdot \sqrt[3]{3}} \cdot \frac{\cos^{-1} \left(\sqrt{t} \cdot \left(1.5 \cdot \frac{\frac{x}{y \cdot 27}}{z}\right)\right)}{\sqrt[3]{3}}(FPCore (x y z t) :precision binary64 (* (/ 1.0 3.0) (acos (* (/ (* 3.0 (/ x (* y 27.0))) (* z 2.0)) (sqrt t)))))
(FPCore (x y z t) :precision binary64 (* (/ 1.0 (* (cbrt 3.0) (cbrt 3.0))) (/ (acos (* (sqrt t) (* 1.5 (/ (/ x (* y 27.0)) z)))) (cbrt 3.0))))
double code(double x, double y, double z, double t) {
return (1.0 / 3.0) * acos(((3.0 * (x / (y * 27.0))) / (z * 2.0)) * sqrt(t));
}
double code(double x, double y, double z, double t) {
return (1.0 / (cbrt(3.0) * cbrt(3.0))) * (acos(sqrt(t) * (1.5 * ((x / (y * 27.0)) / z))) / cbrt(3.0));
}







Bits error versus x







Bits error versus y







Bits error versus z







Bits error versus t
Results
| Original | 1.3 |
|---|---|
| Target | 1.2 |
| Herbie | 0.3 |
| Alternative 1 | |
|---|---|
| Error | 0.3 |
| Cost | 26432 |
| Alternative 2 | |
|---|---|
| Error | 1.3 |
| Cost | 13504 |
| Alternative 3 | |
|---|---|
| Error | 51.9 |
| Cost | 64 |

Initial program 1.3
rmApplied add-cube-cbrt_binary64_209141.3
Applied add-sqr-sqrt_binary64_209011.3
Applied times-frac_binary64_208850.3
Applied associate-*l*_binary64_208200.3
Simplified0.3
Simplified0.3
Final simplification0.3
herbie shell --seed 2021044
(FPCore (x y z t)
:name "Diagrams.Solve.Polynomial:cubForm from diagrams-solve-0.1, D"
:precision binary64
:herbie-target
(/ (acos (* (/ (/ x 27.0) (* y z)) (/ (sqrt t) (/ 2.0 3.0)))) 3.0)
(* (/ 1.0 3.0) (acos (* (/ (* 3.0 (/ x (* y 27.0))) (* z 2.0)) (sqrt t)))))