Average Error: 52.6 → 0.1
Time: 15.7s
Precision: 64
Internal Precision: 2368
\[\log \left(x + \sqrt{x \cdot x + 1}\right)\]
\[\begin{array}{l} \mathbf{if}\;x \le -1.0667380100808137:\\ \;\;\;\;\log \left(\frac{\frac{-1}{2}}{x} + \left(\frac{\frac{\frac{1}{8}}{x}}{x \cdot x} + \frac{\frac{-1}{16}}{{x}^{5}}\right)\right)\\ \mathbf{elif}\;x \le 0.007994010655384562:\\ \;\;\;\;\left(x + {x}^{5} \cdot \frac{3}{40}\right) - {x}^{3} \cdot \frac{1}{6}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2} \cdot \log \left(\sqrt{1^2 + x^2}^* + x\right) + \log \left(\sqrt{e^{\log \left(\sqrt{1^2 + x^2}^* + x\right)}}\right)\\ \end{array}\]

Error

Bits error versus x

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Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original52.6
Target44.9
Herbie0.1
\[\begin{array}{l} \mathbf{if}\;x \lt 0:\\ \;\;\;\;\log \left(\frac{-1}{x - \sqrt{x \cdot x + 1}}\right)\\ \mathbf{else}:\\ \;\;\;\;\log \left(x + \sqrt{x \cdot x + 1}\right)\\ \end{array}\]

Derivation

  1. Split input into 3 regimes
  2. if x < -1.0667380100808137

    1. Initial program 61.8

      \[\log \left(x + \sqrt{x \cdot x + 1}\right)\]
    2. Initial simplification61.0

      \[\leadsto \log \left(x + \sqrt{1^2 + x^2}^*\right)\]
    3. Taylor expanded around -inf 0.2

      \[\leadsto \log \color{blue}{\left(\frac{1}{8} \cdot \frac{1}{{x}^{3}} - \left(\frac{1}{16} \cdot \frac{1}{{x}^{5}} + \frac{1}{2} \cdot \frac{1}{x}\right)\right)}\]
    4. Simplified0.2

      \[\leadsto \log \color{blue}{\left(\frac{\frac{-1}{2}}{x} + \left(\frac{\frac{-1}{16}}{{x}^{5}} + \frac{\frac{\frac{1}{8}}{x}}{x \cdot x}\right)\right)}\]

    if -1.0667380100808137 < x < 0.007994010655384562

    1. Initial program 58.9

      \[\log \left(x + \sqrt{x \cdot x + 1}\right)\]
    2. Initial simplification58.9

      \[\leadsto \log \left(x + \sqrt{1^2 + x^2}^*\right)\]
    3. Taylor expanded around 0 0.1

      \[\leadsto \color{blue}{\left(x + \frac{3}{40} \cdot {x}^{5}\right) - \frac{1}{6} \cdot {x}^{3}}\]

    if 0.007994010655384562 < x

    1. Initial program 31.2

      \[\log \left(x + \sqrt{x \cdot x + 1}\right)\]
    2. Initial simplification0.0

      \[\leadsto \log \left(x + \sqrt{1^2 + x^2}^*\right)\]
    3. Using strategy rm
    4. Applied add-sqr-sqrt0.1

      \[\leadsto \log \color{blue}{\left(\sqrt{x + \sqrt{1^2 + x^2}^*} \cdot \sqrt{x + \sqrt{1^2 + x^2}^*}\right)}\]
    5. Applied log-prod0.1

      \[\leadsto \color{blue}{\log \left(\sqrt{x + \sqrt{1^2 + x^2}^*}\right) + \log \left(\sqrt{x + \sqrt{1^2 + x^2}^*}\right)}\]
    6. Using strategy rm
    7. Applied pow1/20.1

      \[\leadsto \log \left(\sqrt{x + \sqrt{1^2 + x^2}^*}\right) + \log \color{blue}{\left({\left(x + \sqrt{1^2 + x^2}^*\right)}^{\frac{1}{2}}\right)}\]
    8. Applied log-pow0.0

      \[\leadsto \log \left(\sqrt{x + \sqrt{1^2 + x^2}^*}\right) + \color{blue}{\frac{1}{2} \cdot \log \left(x + \sqrt{1^2 + x^2}^*\right)}\]
    9. Using strategy rm
    10. Applied add-exp-log0.0

      \[\leadsto \log \left(\sqrt{\color{blue}{e^{\log \left(x + \sqrt{1^2 + x^2}^*\right)}}}\right) + \frac{1}{2} \cdot \log \left(x + \sqrt{1^2 + x^2}^*\right)\]
  3. Recombined 3 regimes into one program.
  4. Final simplification0.1

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \le -1.0667380100808137:\\ \;\;\;\;\log \left(\frac{\frac{-1}{2}}{x} + \left(\frac{\frac{\frac{1}{8}}{x}}{x \cdot x} + \frac{\frac{-1}{16}}{{x}^{5}}\right)\right)\\ \mathbf{elif}\;x \le 0.007994010655384562:\\ \;\;\;\;\left(x + {x}^{5} \cdot \frac{3}{40}\right) - {x}^{3} \cdot \frac{1}{6}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2} \cdot \log \left(\sqrt{1^2 + x^2}^* + x\right) + \log \left(\sqrt{e^{\log \left(\sqrt{1^2 + x^2}^* + x\right)}}\right)\\ \end{array}\]

Runtime

Time bar (total: 15.7s)Debug logProfile

BaselineHerbieOracleSpan%
Regimes31.40.10.031.499.8%
herbie shell --seed 2018297 +o rules:numerics
(FPCore (x)
  :name "Hyperbolic arcsine"

  :herbie-target
  (if (< x 0) (log (/ -1 (- x (sqrt (+ (* x x) 1))))) (log (+ x (sqrt (+ (* x x) 1)))))

  (log (+ x (sqrt (+ (* x x) 1)))))