Average Error: 29.5 → 1.1
Time: 2.4m
Precision: 64
Internal Precision: 1344
\[\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}{2}\]
\[\begin{array}{l} \mathbf{if}\;x \le 1.177664003935763:\\ \;\;\;\;\frac{\left(\left(\frac{2}{3} \cdot {x}^{3} + 2\right) \cdot \left(\frac{2}{3} \cdot {x}^{3} + 2\right) + \left({x}^{2} \cdot {x}^{2} - \left(\frac{2}{3} \cdot {x}^{3} + 2\right) \cdot {x}^{2}\right)\right) \cdot \left(\frac{1}{2} - \left(\frac{1}{8} \cdot {x}^{4} + {x}^{3} \cdot \frac{1}{6}\right)\right)}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\left(e^{x \cdot \varepsilon - x} + \frac{e^{x \cdot \varepsilon - x}}{\varepsilon}\right) - e^{\left(1 + \varepsilon\right) \cdot \left(-x\right)} \cdot \left(\frac{1}{\varepsilon} - 1\right)}{2}\\ \end{array}\]

Error

Bits error versus x

Bits error versus eps

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Split input into 2 regimes
  2. if x < 1.177664003935763

    1. Initial program 38.9

      \[\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}{2}\]
    2. Taylor expanded around 0 1.3

      \[\leadsto \frac{\color{blue}{\left(\frac{2}{3} \cdot {x}^{3} + 2\right) - {x}^{2}}}{2}\]
    3. Using strategy rm
    4. Applied flip--1.3

      \[\leadsto \frac{\color{blue}{\frac{\left(\frac{2}{3} \cdot {x}^{3} + 2\right) \cdot \left(\frac{2}{3} \cdot {x}^{3} + 2\right) - {x}^{2} \cdot {x}^{2}}{\left(\frac{2}{3} \cdot {x}^{3} + 2\right) + {x}^{2}}}}{2}\]
    5. Using strategy rm
    6. Applied flip3-+1.3

      \[\leadsto \frac{\frac{\left(\frac{2}{3} \cdot {x}^{3} + 2\right) \cdot \left(\frac{2}{3} \cdot {x}^{3} + 2\right) - {x}^{2} \cdot {x}^{2}}{\color{blue}{\frac{{\left(\frac{2}{3} \cdot {x}^{3} + 2\right)}^{3} + {\left({x}^{2}\right)}^{3}}{\left(\frac{2}{3} \cdot {x}^{3} + 2\right) \cdot \left(\frac{2}{3} \cdot {x}^{3} + 2\right) + \left({x}^{2} \cdot {x}^{2} - \left(\frac{2}{3} \cdot {x}^{3} + 2\right) \cdot {x}^{2}\right)}}}}{2}\]
    7. Applied associate-/r/1.3

      \[\leadsto \frac{\color{blue}{\frac{\left(\frac{2}{3} \cdot {x}^{3} + 2\right) \cdot \left(\frac{2}{3} \cdot {x}^{3} + 2\right) - {x}^{2} \cdot {x}^{2}}{{\left(\frac{2}{3} \cdot {x}^{3} + 2\right)}^{3} + {\left({x}^{2}\right)}^{3}} \cdot \left(\left(\frac{2}{3} \cdot {x}^{3} + 2\right) \cdot \left(\frac{2}{3} \cdot {x}^{3} + 2\right) + \left({x}^{2} \cdot {x}^{2} - \left(\frac{2}{3} \cdot {x}^{3} + 2\right) \cdot {x}^{2}\right)\right)}}{2}\]
    8. Taylor expanded around 0 1.3

      \[\leadsto \frac{\color{blue}{\left(\frac{1}{2} - \left(\frac{1}{6} \cdot {x}^{3} + \frac{1}{8} \cdot {x}^{4}\right)\right)} \cdot \left(\left(\frac{2}{3} \cdot {x}^{3} + 2\right) \cdot \left(\frac{2}{3} \cdot {x}^{3} + 2\right) + \left({x}^{2} \cdot {x}^{2} - \left(\frac{2}{3} \cdot {x}^{3} + 2\right) \cdot {x}^{2}\right)\right)}{2}\]

    if 1.177664003935763 < x

    1. Initial program 0.4

      \[\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}{2}\]
    2. Taylor expanded around -inf 0.4

      \[\leadsto \frac{\color{blue}{\left(\frac{e^{x \cdot \varepsilon - x}}{\varepsilon} + e^{x \cdot \varepsilon - x}\right)} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}{2}\]
  3. Recombined 2 regimes into one program.
  4. Final simplification1.1

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \le 1.177664003935763:\\ \;\;\;\;\frac{\left(\left(\frac{2}{3} \cdot {x}^{3} + 2\right) \cdot \left(\frac{2}{3} \cdot {x}^{3} + 2\right) + \left({x}^{2} \cdot {x}^{2} - \left(\frac{2}{3} \cdot {x}^{3} + 2\right) \cdot {x}^{2}\right)\right) \cdot \left(\frac{1}{2} - \left(\frac{1}{8} \cdot {x}^{4} + {x}^{3} \cdot \frac{1}{6}\right)\right)}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\left(e^{x \cdot \varepsilon - x} + \frac{e^{x \cdot \varepsilon - x}}{\varepsilon}\right) - e^{\left(1 + \varepsilon\right) \cdot \left(-x\right)} \cdot \left(\frac{1}{\varepsilon} - 1\right)}{2}\\ \end{array}\]

Runtime

Time bar (total: 2.4m)Debug logProfile

BaselineHerbieOracleSpan%
Regimes15.51.10.415.195.7%
herbie shell --seed 2018295 
(FPCore (x eps)
  :name "NMSE Section 6.1 mentioned, A"
  (/ (- (* (+ 1 (/ 1 eps)) (exp (- (* (- 1 eps) x)))) (* (- (/ 1 eps) 1) (exp (- (* (+ 1 eps) x))))) 2))