Average Error: 47.2 → 15.1
Time: 1.6m
Precision: 64
Internal Precision: 3392
\[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]
\[\begin{array}{l} \mathbf{if}\;i \le -747131245814696.0:\\ \;\;\;\;\left({\left(\frac{i}{n}\right)}^{n} - 1\right) \cdot \left(\frac{100}{i} \cdot n\right)\\ \mathbf{elif}\;i \le 22.870542718060396:\\ \;\;\;\;\left(\left(n \cdot \left(\sqrt[3]{i} + \left(\sqrt[3]{{i}^{4}} \cdot \frac{1}{6} + \frac{1}{36} \cdot \sqrt[3]{{i}^{7}}\right)\right)\right) \cdot \left(\left(\sqrt[3]{\frac{1}{i}} + \frac{1}{12} \cdot \sqrt[3]{{i}^{5}}\right) + \sqrt[3]{i \cdot i} \cdot \frac{1}{3}\right)\right) \cdot 100\\ \mathbf{elif}\;i \le 3.4547076553386547 \cdot 10^{+252} \lor \neg \left(i \le 4.97811435192654 \cdot 10^{+305}\right):\\ \;\;\;\;0\\ \mathbf{else}:\\ \;\;\;\;\left(\left(n \cdot {\left(1 + \frac{i}{n}\right)}^{n} - n\right) \cdot \frac{1}{i}\right) \cdot 100\\ \end{array}\]

Error

Bits error versus i

Bits error versus n

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original47.2
Target46.7
Herbie15.1
\[100 \cdot \frac{e^{n \cdot \begin{array}{l} \mathbf{if}\;1 + \frac{i}{n} = 1:\\ \;\;\;\;\frac{i}{n}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{i}{n} \cdot \log \left(1 + \frac{i}{n}\right)}{\left(\frac{i}{n} + 1\right) - 1}\\ \end{array}} - 1}{\frac{i}{n}}\]

Derivation

  1. Split input into 4 regimes
  2. if i < -747131245814696.0

    1. Initial program 27.4

      \[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]
    2. Taylor expanded around inf 62.9

      \[\leadsto \color{blue}{100 \cdot \frac{\left(e^{\left(\log \left(\frac{1}{n}\right) - \log \left(\frac{1}{i}\right)\right) \cdot n} - 1\right) \cdot n}{i}}\]
    3. Simplified18.2

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

    if -747131245814696.0 < i < 22.870542718060396

    1. Initial program 56.9

      \[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]
    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. Using strategy rm
    5. Applied div-inv26.3

      \[\leadsto 100 \cdot \frac{i + \left(i \cdot i\right) \cdot \left(\frac{1}{6} \cdot i + \frac{1}{2}\right)}{\color{blue}{i \cdot \frac{1}{n}}}\]
    6. Applied add-cube-cbrt26.9

      \[\leadsto 100 \cdot \frac{\color{blue}{\left(\sqrt[3]{i + \left(i \cdot i\right) \cdot \left(\frac{1}{6} \cdot i + \frac{1}{2}\right)} \cdot \sqrt[3]{i + \left(i \cdot i\right) \cdot \left(\frac{1}{6} \cdot i + \frac{1}{2}\right)}\right) \cdot \sqrt[3]{i + \left(i \cdot i\right) \cdot \left(\frac{1}{6} \cdot i + \frac{1}{2}\right)}}}{i \cdot \frac{1}{n}}\]
    7. Applied times-frac11.7

      \[\leadsto 100 \cdot \color{blue}{\left(\frac{\sqrt[3]{i + \left(i \cdot i\right) \cdot \left(\frac{1}{6} \cdot i + \frac{1}{2}\right)} \cdot \sqrt[3]{i + \left(i \cdot i\right) \cdot \left(\frac{1}{6} \cdot i + \frac{1}{2}\right)}}{i} \cdot \frac{\sqrt[3]{i + \left(i \cdot i\right) \cdot \left(\frac{1}{6} \cdot i + \frac{1}{2}\right)}}{\frac{1}{n}}\right)}\]
    8. Simplified11.6

      \[\leadsto 100 \cdot \left(\frac{\sqrt[3]{i + \left(i \cdot i\right) \cdot \left(\frac{1}{6} \cdot i + \frac{1}{2}\right)} \cdot \sqrt[3]{i + \left(i \cdot i\right) \cdot \left(\frac{1}{6} \cdot i + \frac{1}{2}\right)}}{i} \cdot \color{blue}{\left(n \cdot \sqrt[3]{i + \left(i \cdot \frac{1}{6} + \frac{1}{2}\right) \cdot \left(i \cdot i\right)}\right)}\right)\]
    9. Taylor expanded around 0 38.3

      \[\leadsto 100 \cdot \left(\color{blue}{\left(\frac{1}{3} \cdot {\left({i}^{2}\right)}^{\frac{1}{3}} + \left({\left(\frac{1}{i}\right)}^{\frac{1}{3}} + \frac{1}{12} \cdot {\left({i}^{5}\right)}^{\frac{1}{3}}\right)\right)} \cdot \left(n \cdot \sqrt[3]{i + \left(i \cdot \frac{1}{6} + \frac{1}{2}\right) \cdot \left(i \cdot i\right)}\right)\right)\]
    10. Simplified11.1

      \[\leadsto 100 \cdot \left(\color{blue}{\left(\sqrt[3]{i \cdot i} \cdot \frac{1}{3} + \left(\frac{1}{12} \cdot \sqrt[3]{{i}^{5}} + \sqrt[3]{\frac{1}{i}}\right)\right)} \cdot \left(n \cdot \sqrt[3]{i + \left(i \cdot \frac{1}{6} + \frac{1}{2}\right) \cdot \left(i \cdot i\right)}\right)\right)\]
    11. Taylor expanded around 0 38.3

      \[\leadsto 100 \cdot \left(\left(\sqrt[3]{i \cdot i} \cdot \frac{1}{3} + \left(\frac{1}{12} \cdot \sqrt[3]{{i}^{5}} + \sqrt[3]{\frac{1}{i}}\right)\right) \cdot \left(n \cdot \color{blue}{\left({i}^{\frac{1}{3}} + \left(\frac{1}{6} \cdot {\left({i}^{4}\right)}^{\frac{1}{3}} + \frac{1}{36} \cdot {\left({i}^{7}\right)}^{\frac{1}{3}}\right)\right)}\right)\right)\]
    12. Simplified11.1

      \[\leadsto 100 \cdot \left(\left(\sqrt[3]{i \cdot i} \cdot \frac{1}{3} + \left(\frac{1}{12} \cdot \sqrt[3]{{i}^{5}} + \sqrt[3]{\frac{1}{i}}\right)\right) \cdot \left(n \cdot \color{blue}{\left(\left(\frac{1}{6} \cdot \sqrt[3]{{i}^{4}} + \sqrt[3]{{i}^{7}} \cdot \frac{1}{36}\right) + \sqrt[3]{i}\right)}\right)\right)\]

    if 22.870542718060396 < i < 3.4547076553386547e+252 or 4.97811435192654e+305 < i

    1. Initial program 31.9

      \[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]
    2. Taylor expanded around 0 29.1

      \[\leadsto \color{blue}{0}\]

    if 3.4547076553386547e+252 < i < 4.97811435192654e+305

    1. Initial program 30.3

      \[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]
    2. Using strategy rm
    3. Applied div-inv30.3

      \[\leadsto 100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\color{blue}{i \cdot \frac{1}{n}}}\]
    4. Applied *-un-lft-identity30.3

      \[\leadsto 100 \cdot \frac{\color{blue}{1 \cdot \left({\left(1 + \frac{i}{n}\right)}^{n} - 1\right)}}{i \cdot \frac{1}{n}}\]
    5. Applied times-frac30.3

      \[\leadsto 100 \cdot \color{blue}{\left(\frac{1}{i} \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{1}{n}}\right)}\]
    6. Simplified30.3

      \[\leadsto 100 \cdot \left(\frac{1}{i} \cdot \color{blue}{\left({\left(\frac{i}{n} + 1\right)}^{n} \cdot n - n\right)}\right)\]
  3. Recombined 4 regimes into one program.
  4. Final simplification15.1

    \[\leadsto \begin{array}{l} \mathbf{if}\;i \le -747131245814696.0:\\ \;\;\;\;\left({\left(\frac{i}{n}\right)}^{n} - 1\right) \cdot \left(\frac{100}{i} \cdot n\right)\\ \mathbf{elif}\;i \le 22.870542718060396:\\ \;\;\;\;\left(\left(n \cdot \left(\sqrt[3]{i} + \left(\sqrt[3]{{i}^{4}} \cdot \frac{1}{6} + \frac{1}{36} \cdot \sqrt[3]{{i}^{7}}\right)\right)\right) \cdot \left(\left(\sqrt[3]{\frac{1}{i}} + \frac{1}{12} \cdot \sqrt[3]{{i}^{5}}\right) + \sqrt[3]{i \cdot i} \cdot \frac{1}{3}\right)\right) \cdot 100\\ \mathbf{elif}\;i \le 3.4547076553386547 \cdot 10^{+252} \lor \neg \left(i \le 4.97811435192654 \cdot 10^{+305}\right):\\ \;\;\;\;0\\ \mathbf{else}:\\ \;\;\;\;\left(\left(n \cdot {\left(1 + \frac{i}{n}\right)}^{n} - n\right) \cdot \frac{1}{i}\right) \cdot 100\\ \end{array}\]

Runtime

Time bar (total: 1.6m)Debug logProfile

herbie shell --seed 2018242 
(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))))