Data.Colour.CIE:cieLAB from colour-2.3.3, A

Average Error: 0.3 → 0.3

Time: 21.1s

Precision: 64

Math

\[\left(\left(x - \frac{16}{116}\right) \cdot 3\right) \cdot y\]

↓

\[\left(\left(x - \frac{16}{116}\right) \cdot 3\right) \cdot y\]

C

double f(double x, double y) {
        double r573853 = x;
        double r573854 = 16.0;
        double r573855 = 116.0;
        double r573856 = r573854 / r573855;
        double r573857 = r573853 - r573856;
        double r573858 = 3.0;
        double r573859 = r573857 * r573858;
        double r573860 = y;
        double r573861 = r573859 * r573860;
        return r573861;
}

↓

double f(double x, double y) {
        double r573862 = x;
        double r573863 = 16.0;
        double r573864 = 116.0;
        double r573865 = r573863 / r573864;
        double r573866 = r573862 - r573865;
        double r573867 = 3.0;
        double r573868 = r573866 * r573867;
        double r573869 = y;
        double r573870 = r573868 * r573869;
        return r573870;
}

Error

Bits error versus x

Bits error versus y

Target

Original	0.3
Target	0.3
Herbie	0.3

\[y \cdot \left(x \cdot 3 - 0.413793103448275856\right)\]

Derivation

1. Initial program 0.3

   \[\left(\left(x - \frac{16}{116}\right) \cdot 3\right) \cdot y\]

2. Final simplification 0.3

   \[\leadsto \left(\left(x - \frac{16}{116}\right) \cdot 3\right) \cdot y\]

Reproduce

herbie shell --seed 2019199 
(FPCore (x y)
  :name "Data.Colour.CIE:cieLAB from colour-2.3.3, A"

  :herbie-target
  (* y (- (* x 3.0) 0.41379310344827586))

  (* (* (- x (/ 16.0 116.0)) 3.0) y))