Average Error: 29.2 → 0.0
Time: 11.7s
Precision: 64
Internal Precision: 1344
\[\log \left(N + 1\right) - \log N\]
\[\begin{array}{l} \mathbf{if}\;N \le 6215.347060402761:\\ \;\;\;\;\log \left(\sqrt{1 + \frac{1}{N}}\right) + \log \left(\sqrt{1 + \frac{1}{N}}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{N} - \left(\frac{1}{2} - \frac{\frac{1}{3}}{N}\right) \cdot \frac{1}{N \cdot N}\\ \end{array}\]

Error

Bits error versus N

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Split input into 2 regimes
  2. if N < 6215.347060402761

    1. Initial program 0.1

      \[\log \left(N + 1\right) - \log N\]
    2. Using strategy rm
    3. Applied diff-log0.0

      \[\leadsto \color{blue}{\log \left(\frac{N + 1}{N}\right)}\]
    4. Taylor expanded around inf 0.0

      \[\leadsto \log \color{blue}{\left(\frac{1}{N} + 1\right)}\]
    5. Using strategy rm
    6. Applied add-sqr-sqrt0.1

      \[\leadsto \log \color{blue}{\left(\sqrt{\frac{1}{N} + 1} \cdot \sqrt{\frac{1}{N} + 1}\right)}\]
    7. Applied log-prod0.1

      \[\leadsto \color{blue}{\log \left(\sqrt{\frac{1}{N} + 1}\right) + \log \left(\sqrt{\frac{1}{N} + 1}\right)}\]

    if 6215.347060402761 < N

    1. Initial program 59.4

      \[\log \left(N + 1\right) - \log N\]
    2. Using strategy rm
    3. Applied diff-log59.2

      \[\leadsto \color{blue}{\log \left(\frac{N + 1}{N}\right)}\]
    4. Taylor expanded around -inf 0.0

      \[\leadsto \color{blue}{\left(\frac{1}{3} \cdot \frac{1}{{N}^{3}} + \frac{1}{N}\right) - \frac{1}{2} \cdot \frac{1}{{N}^{2}}}\]
    5. Simplified0.0

      \[\leadsto \color{blue}{\frac{1}{N} - \frac{1}{N \cdot N} \cdot \left(\frac{1}{2} - \frac{\frac{1}{3}}{N}\right)}\]
  3. Recombined 2 regimes into one program.
  4. Final simplification0.0

    \[\leadsto \begin{array}{l} \mathbf{if}\;N \le 6215.347060402761:\\ \;\;\;\;\log \left(\sqrt{1 + \frac{1}{N}}\right) + \log \left(\sqrt{1 + \frac{1}{N}}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{N} - \left(\frac{1}{2} - \frac{\frac{1}{3}}{N}\right) \cdot \frac{1}{N \cdot N}\\ \end{array}\]

Runtime

Time bar (total: 11.7s)Debug logProfile

BaselineHerbieOracleSpan%
Regimes29.10.00.029.1100%
herbie shell --seed 2018295 
(FPCore (N)
  :name "2log (problem 3.3.6)"
  (- (log (+ N 1)) (log N)))