Average Error: 59.6 → 0.7
Time: 3.7m
Precision: 64
Internal Precision: 1344
\[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right)\]
\[\left(\log \left(\sqrt[3]{\tanh \left(\frac{\pi}{4} \cdot f\right)}\right) + \log \left({\left(\tanh \left(\frac{\pi}{4} \cdot f\right)\right)}^{\left(\frac{1}{3} + \frac{1}{3}\right)}\right)\right) \cdot \frac{1}{\frac{\pi}{4}}\]

Error

Bits error versus f

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Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Initial program 59.6

    \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right)\]
  2. Initial simplification0.7

    \[\leadsto \frac{\log \left(\tanh \left(\frac{\pi}{4} \cdot f\right)\right)}{\frac{\pi}{4}}\]
  3. Using strategy rm
  4. Applied add-cube-cbrt0.7

    \[\leadsto \frac{\log \color{blue}{\left(\left(\sqrt[3]{\tanh \left(\frac{\pi}{4} \cdot f\right)} \cdot \sqrt[3]{\tanh \left(\frac{\pi}{4} \cdot f\right)}\right) \cdot \sqrt[3]{\tanh \left(\frac{\pi}{4} \cdot f\right)}\right)}}{\frac{\pi}{4}}\]
  5. Applied log-prod0.8

    \[\leadsto \frac{\color{blue}{\log \left(\sqrt[3]{\tanh \left(\frac{\pi}{4} \cdot f\right)} \cdot \sqrt[3]{\tanh \left(\frac{\pi}{4} \cdot f\right)}\right) + \log \left(\sqrt[3]{\tanh \left(\frac{\pi}{4} \cdot f\right)}\right)}}{\frac{\pi}{4}}\]
  6. Simplified0.7

    \[\leadsto \frac{\color{blue}{\log \left({\left(\tanh \left(\frac{\pi}{4} \cdot f\right)\right)}^{\left(\frac{1}{3} + \frac{1}{3}\right)}\right)} + \log \left(\sqrt[3]{\tanh \left(\frac{\pi}{4} \cdot f\right)}\right)}{\frac{\pi}{4}}\]
  7. Using strategy rm
  8. Applied div-inv0.7

    \[\leadsto \color{blue}{\left(\log \left({\left(\tanh \left(\frac{\pi}{4} \cdot f\right)\right)}^{\left(\frac{1}{3} + \frac{1}{3}\right)}\right) + \log \left(\sqrt[3]{\tanh \left(\frac{\pi}{4} \cdot f\right)}\right)\right) \cdot \frac{1}{\frac{\pi}{4}}}\]
  9. Final simplification0.7

    \[\leadsto \left(\log \left(\sqrt[3]{\tanh \left(\frac{\pi}{4} \cdot f\right)}\right) + \log \left({\left(\tanh \left(\frac{\pi}{4} \cdot f\right)\right)}^{\left(\frac{1}{3} + \frac{1}{3}\right)}\right)\right) \cdot \frac{1}{\frac{\pi}{4}}\]

Runtime

Time bar (total: 3.7m)Debug logProfile

herbie shell --seed 2018214 
(FPCore (f)
  :name "VandenBroeck and Keller, Equation (20)"
  (- (* (/ 1 (/ PI 4)) (log (/ (+ (exp (* (/ PI 4) f)) (exp (- (* (/ PI 4) f)))) (- (exp (* (/ PI 4) f)) (exp (- (* (/ PI 4) f)))))))))