Average Error: 24.7 → 7.8
Time: 8.0s
Precision: binary64
\[\]
\[\]
double code(double x, double y, double z, double t) {
	return ((double) (x - ((double) (((double) log(((double) (((double) (1.0 - y)) + ((double) (y * ((double) exp(z)))))))) / t))));
}
double code(double x, double y, double z, double t) {
	double VAR;
	if ((z <= -0.0006917303965414979)) {
		VAR = ((double) (x + ((double) (-1.0 / ((double) (t / ((double) log(((double) (((double) (y * ((double) exp(z)))) + ((double) (1.0 - y))))))))))));
	} else {
		VAR = ((double) (x - ((double) (((double) (1.0 * ((double) (y * ((double) (z / t)))))) + ((double) (((double) (((double) log(1.0)) / t)) + ((double) (0.5 * ((double) (y * ((double) (z / ((double) (t / z))))))))))))));
	}
	return VAR;
}

Error

Bits error versus x

Bits error versus y

Bits error versus z

Bits error versus t

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original24.7
Target16.3
Herbie7.8
\[\]

Derivation

  1. Split input into 2 regimes
  2. if z < -6.91730396541497873e-4

    1. Initial program 11.9

      \[\]
    2. Simplified11.9

      \[\leadsto \]
    3. Using strategy rm
    4. Applied clear-num11.9

      \[\leadsto \]
    5. Simplified11.9

      \[\leadsto \]

    if -6.91730396541497873e-4 < z

    1. Initial program 30.2

      \[\]
    2. Simplified15.6

      \[\leadsto \]
    3. Taylor expanded around 0 7.0

      \[\leadsto \]
    4. Simplified6.0

      \[\leadsto \]
  3. Recombined 2 regimes into one program.
  4. Final simplification7.8

    \[\leadsto \]

Reproduce

herbie shell --seed 2020190 
(FPCore (x y z t)
  :name "System.Random.MWC.Distributions:truncatedExp from mwc-random-0.13.3.2"
  :precision binary64

  :herbie-target
  (if (< z -2.8874623088207947e+119) (- (- x (/ (/ (neg 0.5) (* y t)) (* z z))) (* (/ (neg 0.5) (* y t)) (/ (/ 2.0 z) (* z z)))) (- x (/ (log (+ 1.0 (* z y))) t)))

  (- x (/ (log (+ (- 1.0 y) (* y (exp z)))) t)))