Average Error: 47.0 → 14.5
Time: 46.4s
Precision: 64
Internal Precision: 3392
\[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]
↓
\[\begin{array}{l} \mathbf{if}\;i \le -0.8608082000356796:\\ \;\;\;\;100 \cdot \frac{{\left(\frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\\ \mathbf{elif}\;i \le 1.83911736767673 \cdot 10^{-14}:\\ \;\;\;\;\left(n + \left(\sqrt[3]{i \cdot \frac{1}{6}} \cdot e^{\log \left(\sqrt[3]{i \cdot \frac{1}{6}} \cdot \sqrt[3]{i \cdot \frac{1}{6}}\right)} + \frac{1}{2}\right) \cdot \left(n \cdot i\right)\right) \cdot 100\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array}\]

Error

Bits error versus i

Bits error versus n

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original47.0
Target47.0
Herbie14.5
\[100 \cdot \frac{e^{n \cdot \begin{array}{l} \mathbf{if}\;1 + \frac{i}{n} = 1:\\ \;\;\;\;\frac{i}{n}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{i}{n} \cdot \log \left(1 + \frac{i}{n}\right)}{\left(\frac{i}{n} + 1\right) - 1}\\ \end{array}} - 1}{\frac{i}{n}}\]

Derivation

  1. Split input into 3 regimes

  2. if i < -0.8608082000356796

    1. Initial program 26.8

      \[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]

    2. Taylor expanded around inf 62.9

      \[\leadsto 100 \cdot \frac{\color{blue}{e^{\left(\log \left(\frac{1}{n}\right) - \log \left(\frac{1}{i}\right)\right) \cdot n}} - 1}{\frac{i}{n}}\]

    3. Simplified17.6

      \[\leadsto 100 \cdot \frac{\color{blue}{{\left(\frac{i}{n}\right)}^{n}} - 1}{\frac{i}{n}}\]

    if -0.8608082000356796 < i < 1.83911736767673e-14

    1. Initial program 57.7

      \[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]

    2. Taylor expanded around 0 26.2

      \[\leadsto 100 \cdot \frac{\color{blue}{i + \left(\frac{1}{2} \cdot {i}^{2} + \frac{1}{6} \cdot {i}^{3}\right)}}{\frac{i}{n}}\]

    3. Simplified26.2

      \[\leadsto 100 \cdot \frac{\color{blue}{i + \left(i \cdot i\right) \cdot \left(\frac{1}{6} \cdot i + \frac{1}{2}\right)}}{\frac{i}{n}}\]

    4. Taylor expanded around -inf 9.1

      \[\leadsto 100 \cdot \color{blue}{\left(\frac{1}{6} \cdot \left({i}^{2} \cdot n\right) + \left(n + \frac{1}{2} \cdot \left(i \cdot n\right)\right)\right)}\]

    5. Simplified9.1

      \[\leadsto 100 \cdot \color{blue}{\left(n + \left(i \cdot n\right) \cdot \left(\frac{1}{6} \cdot i + \frac{1}{2}\right)\right)}\]
    6. Using strategy rm

    7. Applied add-cube-cbrt9.1

      \[\leadsto 100 \cdot \left(n + \left(i \cdot n\right) \cdot \left(\color{blue}{\left(\sqrt[3]{\frac{1}{6} \cdot i} \cdot \sqrt[3]{\frac{1}{6} \cdot i}\right) \cdot \sqrt[3]{\frac{1}{6} \cdot i}} + \frac{1}{2}\right)\right)\]
    8. Using strategy rm

    9. Applied add-exp-log9.1

      \[\leadsto 100 \cdot \left(n + \left(i \cdot n\right) \cdot \left(\color{blue}{e^{\log \left(\sqrt[3]{\frac{1}{6} \cdot i} \cdot \sqrt[3]{\frac{1}{6} \cdot i}\right)}} \cdot \sqrt[3]{\frac{1}{6} \cdot i} + \frac{1}{2}\right)\right)\]

    if 1.83911736767673e-14 < i

    1. Initial program 32.9

      \[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]

    2. Taylor expanded around 0 33.4

      \[\leadsto \color{blue}{0}\]
  3. Recombined 3 regimes into one program.

  4. Final simplification14.5

    \[\leadsto \begin{array}{l} \mathbf{if}\;i \le -0.8608082000356796:\\ \;\;\;\;100 \cdot \frac{{\left(\frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\\ \mathbf{elif}\;i \le 1.83911736767673 \cdot 10^{-14}:\\ \;\;\;\;\left(n + \left(\sqrt[3]{i \cdot \frac{1}{6}} \cdot e^{\log \left(\sqrt[3]{i \cdot \frac{1}{6}} \cdot \sqrt[3]{i \cdot \frac{1}{6}}\right)} + \frac{1}{2}\right) \cdot \left(n \cdot i\right)\right) \cdot 100\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array}\]

Runtime

Time bar (total: 46.4s)Debug logProfile

herbie shell --seed 2018256 
(FPCore (i n)
  :name "Compound Interest"

  :herbie-target
  (* 100 (/ (- (exp (* n (if (== (+ 1 (/ i n)) 1) (/ i n) (/ (* (/ i n) (log (+ 1 (/ i n)))) (- (+ (/ i n) 1) 1))))) 1) (/ i n)))

  (* 100 (/ (- (pow (+ 1 (/ i n)) n) 1) (/ i n))))