Average Error: 29.5 → 0.2
Time: 15.4s
Precision: 64
Internal precision: 1408
\[\log \left(N + 1\right) - \log N\]
⬇
\[\begin{array}{l}
\mathbf{if}\;N \le 83873799.46063499:\\
\;\;\;\;\log \left({N}^{3} + {1}^{3}\right) - \left(\log N + \log \left(N \cdot N - \left(N - 1\right)\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{\frac{1}{3}}{N} - \frac{1}{2}}{{N}^2} + \frac{1}{N}\\
\end{array}\]
Derivation
- Split input into 2 regimes.
-
if N < 83873799.46063499
Initial program 0.4
\[\log \left(N + 1\right) - \log N\]
- Using strategy
rm
Applied flip3-+ 0.4
\[\leadsto \log \color{blue}{\left(\frac{{N}^{3} + {1}^{3}}{{N}^2 + \left({1}^2 - N \cdot 1\right)}\right)} - \log N\]
Applied log-div 0.5
\[\leadsto \color{blue}{\left(\log \left({N}^{3} + {1}^{3}\right) - \log \left({N}^2 + \left({1}^2 - N \cdot 1\right)\right)\right)} - \log N\]
Applied associate--l- 0.5
\[\leadsto \color{blue}{\log \left({N}^{3} + {1}^{3}\right) - \left(\log \left({N}^2 + \left({1}^2 - N \cdot 1\right)\right) + \log N\right)}\]
Applied simplify 0.5
\[\leadsto \log \left({N}^{3} + {1}^{3}\right) - \color{blue}{\left(\log N + \log \left(N \cdot N - \left(N - 1\right)\right)\right)}\]
if 83873799.46063499 < N
Initial program 60.0
\[\log \left(N + 1\right) - \log N\]
Applied taylor 0.0
\[\leadsto \left(\frac{1}{3} \cdot \frac{1}{{N}^{3}} + \frac{1}{N}\right) - \frac{1}{2} \cdot \frac{1}{{N}^2}\]
Taylor expanded around inf 0.0
\[\leadsto \color{blue}{\left(\frac{1}{3} \cdot \frac{1}{{N}^{3}} + \frac{1}{N}\right) - \frac{1}{2} \cdot \frac{1}{{N}^2}}\]
Applied simplify 0.0
\[\leadsto \color{blue}{\frac{1}{N \cdot N} \cdot \left(\frac{\frac{1}{3}}{N} - \frac{1}{2}\right) + \frac{1}{N}}\]
Applied simplify 0.0
\[\leadsto \color{blue}{\frac{\frac{\frac{1}{3}}{N} - \frac{1}{2}}{{N}^2}} + \frac{1}{N}\]
- Recombined 2 regimes into one program.
- Removed slow pow expressions
Runtime
Please include this information when filing a bug report:
herbie shell --seed '#(1064651971 495577305 2200811460 13024471 864198081 231948279)'
(FPCore (N)
:name "2log (problem 3.3.6)"
(- (log (+ N 1)) (log N)))