System.Random.MWC.Distributions:gamma from mwc-random-0.13.3.2

Average Error: 0.1 → 0.1

Time: 32.6s

Precision: 64

Math

\[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)\]

↓

\[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)\]

C

double f(double x, double y, double z) {
        double r58021628 = x;
        double r58021629 = 0.5;
        double r58021630 = r58021628 * r58021629;
        double r58021631 = y;
        double r58021632 = 1.0;
        double r58021633 = z;
        double r58021634 = r58021632 - r58021633;
        double r58021635 = log(r58021633);
        double r58021636 = r58021634 + r58021635;
        double r58021637 = r58021631 * r58021636;
        double r58021638 = r58021630 + r58021637;
        return r58021638;
}

↓

double f(double x, double y, double z) {
        double r58021639 = x;
        double r58021640 = 0.5;
        double r58021641 = r58021639 * r58021640;
        double r58021642 = y;
        double r58021643 = 1.0;
        double r58021644 = z;
        double r58021645 = r58021643 - r58021644;
        double r58021646 = log(r58021644);
        double r58021647 = r58021645 + r58021646;
        double r58021648 = r58021642 * r58021647;
        double r58021649 = r58021641 + r58021648;
        return r58021649;
}

Error

Bits error versus x

Bits error versus y

Bits error versus z

Target

Original	0.1
Target	0.1
Herbie	0.1

\[\left(y + 0.5 \cdot x\right) - y \cdot \left(z - \log z\right)\]

Derivation

1. Initial program 0.1

   \[x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)\]

2. Final simplification 0.1

   \[\leadsto x \cdot 0.5 + y \cdot \left(\left(1 - z\right) + \log z\right)\]

Reproduce

herbie shell --seed 2019173 
(FPCore (x y z)
  :name "System.Random.MWC.Distributions:gamma from mwc-random-0.13.3.2"

  :herbie-target
  (- (+ y (* 0.5 x)) (* y (- z (log z))))

  (+ (* x 0.5) (* y (+ (- 1.0 z) (log z)))))