Average Error: 36.9 → 15.4
Time: 16.2s
Precision: binary64
\[\]
\[\]
double code(double x, double eps) {
	return ((double) (((double) tan(((double) (x + eps)))) - ((double) tan(x))));
}
double code(double x, double eps) {
	double VAR;
	if ((eps <= -6.583395804010651e-55)) {
		VAR = ((double) (((double) (((double) (((double) tan(x)) + ((double) tan(eps)))) / ((double) (1.0 - ((double) (((double) (((double) tan(x)) * ((double) sin(eps)))) / ((double) cos(eps)))))))) - ((double) tan(x))));
	} else {
		double VAR_1;
		if ((eps <= 2.6174394417726606e-73)) {
			VAR_1 = ((double) (eps + ((double) (x * ((double) (eps * ((double) (eps + x))))))));
		} else {
			VAR_1 = ((double) (((double) (((double) (((double) (((double) (((double) cos(eps)) * ((double) sin(x)))) + ((double) (((double) sin(eps)) * ((double) cos(x)))))) / ((double) (((double) cos(eps)) * ((double) cos(x)))))) / ((double) (1.0 - ((double) (((double) tan(x)) * ((double) tan(eps)))))))) - ((double) tan(x))));
		}
		VAR = VAR_1;
	}
	return VAR;
}

Error

Bits error versus x

Bits error versus eps

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original36.9
Target15.1
Herbie15.4
\[\]

Derivation

  1. Split input into 3 regimes
  2. if eps < -6.5833958040106514e-55

    1. Initial program 30.1

      \[\]
    2. Using strategy rm
    3. Applied tan-sum4.1

      \[\leadsto \]
    4. Using strategy rm
    5. Applied tan-quot4.2

      \[\leadsto \]
    6. Applied associate-*r/4.2

      \[\leadsto \]

    if -6.5833958040106514e-55 < eps < 2.61743944177266056e-73

    1. Initial program 47.8

      \[\]
    2. Taylor expanded around 0 31.6

      \[\leadsto \]
    3. Simplified31.3

      \[\leadsto \]

    if 2.61743944177266056e-73 < eps

    1. Initial program 29.7

      \[\]
    2. Using strategy rm
    3. Applied tan-sum5.9

      \[\leadsto \]
    4. Using strategy rm
    5. Applied tan-quot6.1

      \[\leadsto \]
    6. Applied tan-quot6.1

      \[\leadsto \]
    7. Applied frac-add6.1

      \[\leadsto \]
  3. Recombined 3 regimes into one program.
  4. Final simplification15.4

    \[\leadsto \]

Reproduce

herbie shell --seed 2020191 
(FPCore (x eps)
  :name "2tan (problem 3.3.2)"
  :precision binary64

  :herbie-target
  (/ (sin eps) (* (cos x) (cos (+ x eps))))

  (- (tan (+ x eps)) (tan x)))