Average Error: 40.4 → 19.9
Time: 5.7s
Precision: 64
Internal precision: 1408
\[\log \left(N + 1\right) - \log N\]
⬇
\[\begin{array}{l}
\mathbf{if}\;N \le 550698777842538.4:\\
\;\;\;\;\log \left(\frac{N + 1}{N}\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{N} + \frac{\frac{\frac{1}{3}}{N} - \frac{1}{2}}{N \cdot N}\\
\end{array}\]
Derivation
- Split input into 2 regimes.
-
if N < 550698777842538.4
Initial program 31.4
\[\log \left(N + 1\right) - \log N\]
- Using strategy
rm
Applied diff-log 29.0
\[\leadsto \color{blue}{\log \left(\frac{N + 1}{N}\right)}\]
if 550698777842538.4 < N
Initial program 60.4
\[\log \left(N + 1\right) - \log N\]
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
\[\leadsto \color{blue}{\frac{1}{N} + \left(\frac{\frac{1}{3}}{N} - \frac{1}{2}\right) \cdot \frac{1}{N \cdot N}}\]
Applied simplify 0.0
\[\leadsto \frac{1}{N} + \color{blue}{\frac{\frac{\frac{1}{3}}{N} - \frac{1}{2}}{N \cdot N}}\]
- Recombined 2 regimes into one program.
- Removed slow pow expressions
Runtime
Please include this information when filing a bug report:
herbie shell --seed '#(1067901057 3396600083 3715501224 3126139233 3908045574 1593683916)'
(FPCore (N)
:name "2log (problem 3.3.6)"
(- (log (+ N 1)) (log N)))