Average Error: 59.7 → 2.0
Time: 1.6m
Precision: 64
Internal Precision: 1344
\[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right)\]
\[-\frac{\left(\log \left(\frac{4}{\pi}\right) + \left({f}^{4} \cdot {\pi}^{4}\right) \cdot \frac{-7}{23040}\right) - \left(\log f - \frac{1}{48} \cdot \left(\left(\pi \cdot f\right) \cdot \left(\pi \cdot f\right)\right)\right)}{\frac{\pi}{4}}\]

Error

Bits error versus f

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Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Initial program 59.7

    \[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right)\]
  2. Taylor expanded around 0 2.0

    \[\leadsto -\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{\color{blue}{\frac{1}{2} \cdot \left(f \cdot \pi\right) + \left(\frac{1}{192} \cdot \left({f}^{3} \cdot {\pi}^{3}\right) + \frac{1}{61440} \cdot \left({f}^{5} \cdot {\pi}^{5}\right)\right)}}\right)\]
  3. Taylor expanded around 0 2.0

    \[\leadsto -\frac{1}{\frac{\pi}{4}} \cdot \color{blue}{\left(\left(\log \left(\frac{4}{\pi}\right) + \frac{1}{48} \cdot \left({f}^{2} \cdot {\pi}^{2}\right)\right) - \left(\frac{7}{23040} \cdot \left({f}^{4} \cdot {\pi}^{4}\right) + \log f\right)\right)}\]
  4. Using strategy rm
  5. Applied pow-to-exp2.0

    \[\leadsto -\frac{1}{\frac{\pi}{4}} \cdot \left(\left(\log \left(\frac{4}{\pi}\right) + \frac{1}{48} \cdot \left({f}^{2} \cdot \color{blue}{e^{\log \pi \cdot 2}}\right)\right) - \left(\frac{7}{23040} \cdot \left({f}^{4} \cdot {\pi}^{4}\right) + \log f\right)\right)\]
  6. Applied pow-to-exp2.0

    \[\leadsto -\frac{1}{\frac{\pi}{4}} \cdot \left(\left(\log \left(\frac{4}{\pi}\right) + \frac{1}{48} \cdot \left(\color{blue}{e^{\log f \cdot 2}} \cdot e^{\log \pi \cdot 2}\right)\right) - \left(\frac{7}{23040} \cdot \left({f}^{4} \cdot {\pi}^{4}\right) + \log f\right)\right)\]
  7. Applied prod-exp2.0

    \[\leadsto -\frac{1}{\frac{\pi}{4}} \cdot \left(\left(\log \left(\frac{4}{\pi}\right) + \frac{1}{48} \cdot \color{blue}{e^{\log f \cdot 2 + \log \pi \cdot 2}}\right) - \left(\frac{7}{23040} \cdot \left({f}^{4} \cdot {\pi}^{4}\right) + \log f\right)\right)\]
  8. Simplified2.0

    \[\leadsto -\frac{1}{\frac{\pi}{4}} \cdot \left(\left(\log \left(\frac{4}{\pi}\right) + \frac{1}{48} \cdot e^{\color{blue}{2 \cdot \left(\log f + \log \pi\right)}}\right) - \left(\frac{7}{23040} \cdot \left({f}^{4} \cdot {\pi}^{4}\right) + \log f\right)\right)\]
  9. Using strategy rm
  10. Applied associate-*l/2.0

    \[\leadsto -\color{blue}{\frac{1 \cdot \left(\left(\log \left(\frac{4}{\pi}\right) + \frac{1}{48} \cdot e^{2 \cdot \left(\log f + \log \pi\right)}\right) - \left(\frac{7}{23040} \cdot \left({f}^{4} \cdot {\pi}^{4}\right) + \log f\right)\right)}{\frac{\pi}{4}}}\]
  11. Simplified2.0

    \[\leadsto -\frac{\color{blue}{\left(\log \left(\frac{4}{\pi}\right) + \left({f}^{4} \cdot {\pi}^{4}\right) \cdot \frac{-7}{23040}\right) - \left(\log f - \left(\left(f \cdot \pi\right) \cdot \left(f \cdot \pi\right)\right) \cdot \frac{1}{48}\right)}}{\frac{\pi}{4}}\]
  12. Final simplification2.0

    \[\leadsto -\frac{\left(\log \left(\frac{4}{\pi}\right) + \left({f}^{4} \cdot {\pi}^{4}\right) \cdot \frac{-7}{23040}\right) - \left(\log f - \frac{1}{48} \cdot \left(\left(\pi \cdot f\right) \cdot \left(\pi \cdot f\right)\right)\right)}{\frac{\pi}{4}}\]

Runtime

Time bar (total: 1.6m)Debug logProfile

BaselineHerbieOracleSpan%
Regimes2.02.01.40.60%
herbie shell --seed 2018295 
(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)))))))))