Average Error: 16.0 → 5.9
Time: 3.4s
Precision: binary64
\[\]
\[\]
\[\]
double code(double alpha, double beta) {
	return ((double) (((double) (((double) (((double) (beta - alpha)) / ((double) (((double) (alpha + beta)) + 2.0)))) + 1.0)) / 2.0));
}
double code(double alpha, double beta) {
	double VAR;
	if ((alpha <= 4461477303.925521)) {
		VAR = ((double) (((double) (((double) (((double) (beta / ((double) sqrt(((double) (alpha + ((double) (beta + 2.0)))))))) / ((double) sqrt(((double) (2.0 + ((double) (alpha + beta)))))))) + ((double) (1.0 - ((double) (alpha / ((double) (beta + ((double) (alpha + 2.0)))))))))) / 2.0));
	} else {
		VAR = ((double) (((double) (((double) (beta / ((double) (2.0 + ((double) (alpha + beta)))))) + ((double) (((double) (((double) (2.0 / alpha)) + ((double) (8.0 / ((double) pow(alpha, 3.0)))))) - ((double) (4.0 / ((double) (alpha * alpha)))))))) / 2.0));
	}
	return VAR;
}

Error

Bits error versus alpha

Bits error versus beta

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Split input into 2 regimes
  2. if alpha < 4461477303.9255209

    1. Initial program 0.1

      \[\]
    2. Using strategy rm
    3. Applied div-sub0.1

      \[\leadsto \]
    4. Applied associate-+l-0.1

      \[\leadsto \]
    5. Simplified0.1

      \[\leadsto \]
    6. Using strategy rm
    7. Applied add-sqr-sqrt0.1

      \[\leadsto \]
    8. Applied associate-/r*0.2

      \[\leadsto \]
    9. Simplified0.2

      \[\leadsto \]

    if 4461477303.9255209 < alpha

    1. Initial program 49.5

      \[\]
    2. Using strategy rm
    3. Applied div-sub49.5

      \[\leadsto \]
    4. Applied associate-+l-48.0

      \[\leadsto \]
    5. Simplified48.0

      \[\leadsto \]
    6. Taylor expanded around inf 18.2

      \[\leadsto \]
    7. Simplified18.2

      \[\leadsto \]
  3. Recombined 2 regimes into one program.
  4. Final simplification5.9

    \[\leadsto \]

Reproduce

herbie shell --seed 2020192 
(FPCore (alpha beta)
  :name "Octave 3.8, jcobi/1"
  :precision binary64
  :pre (and (> alpha -1.0) (> beta -1.0))
  (/ (+ (/ (- beta alpha) (+ (+ alpha beta) 2.0)) 1.0) 2.0))