Average Error: 42.0 → 20.0
Time: 39.3s
Precision: 64
Internal Precision: 128
\[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]
\[\begin{array}{l} \mathbf{if}\;n \le -8.764753048170504 \cdot 10^{+49}:\\ \;\;\;\;100 \cdot \frac{(e^{i} - 1)^*}{\frac{i}{n}}\\ \mathbf{elif}\;n \le -3.869064973251871 \cdot 10^{-99}:\\ \;\;\;\;\frac{\left({\left(\frac{i}{n} + 1\right)}^{n} - 1\right) \cdot 100}{\frac{i}{n}}\\ \mathbf{elif}\;n \le -2.549728235978189 \cdot 10^{-174}:\\ \;\;\;\;100 \cdot \left(\frac{(e^{\log_* (1 + \frac{i}{n}) \cdot n} - 1)^*}{\sqrt{\frac{i}{n}}} \cdot \frac{1}{\sqrt{\frac{i}{n}}}\right)\\ \mathbf{elif}\;n \le 5.831751074444269 \cdot 10^{-195}:\\ \;\;\;\;0\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\frac{(e^{\log_* (1 + \frac{i}{n}) \cdot n} - 1)^*}{\frac{i}{n}}} \cdot \left(100 \cdot \sqrt{\frac{(e^{\log_* (1 + \frac{i}{n}) \cdot n} - 1)^*}{\frac{i}{n}}}\right)\\ \end{array}\]

Error

Bits error versus i

Bits error versus n

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original42.0
Target41.8
Herbie20.0
\[100 \cdot \frac{e^{n \cdot \begin{array}{l} \mathbf{if}\;1 + \frac{i}{n} = 1:\\ \;\;\;\;\frac{i}{n}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{i}{n} \cdot \log \left(1 + \frac{i}{n}\right)}{\left(\frac{i}{n} + 1\right) - 1}\\ \end{array}} - 1}{\frac{i}{n}}\]

Derivation

  1. Split input into 5 regimes
  2. if n < -8.764753048170504e+49

    1. Initial program 45.8

      \[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]
    2. Using strategy rm
    3. Applied add-exp-log53.6

      \[\leadsto 100 \cdot \frac{{\color{blue}{\left(e^{\log \left(1 + \frac{i}{n}\right)}\right)}}^{n} - 1}{\frac{i}{n}}\]
    4. Applied pow-exp53.6

      \[\leadsto 100 \cdot \frac{\color{blue}{e^{\log \left(1 + \frac{i}{n}\right) \cdot n}} - 1}{\frac{i}{n}}\]
    5. Applied expm1-def53.6

      \[\leadsto 100 \cdot \frac{\color{blue}{(e^{\log \left(1 + \frac{i}{n}\right) \cdot n} - 1)^*}}{\frac{i}{n}}\]
    6. Simplified27.4

      \[\leadsto 100 \cdot \frac{(e^{\color{blue}{n \cdot \log_* (1 + \frac{i}{n})}} - 1)^*}{\frac{i}{n}}\]
    7. Taylor expanded around inf 42.5

      \[\leadsto 100 \cdot \color{blue}{\frac{\left(e^{i} - 1\right) \cdot n}{i}}\]
    8. Simplified27.0

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

    if -8.764753048170504e+49 < n < -3.869064973251871e-99

    1. Initial program 25.7

      \[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]
    2. Using strategy rm
    3. Applied associate-*r/25.6

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

    if -3.869064973251871e-99 < n < -2.549728235978189e-174

    1. Initial program 18.1

      \[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]
    2. Using strategy rm
    3. Applied add-exp-log18.1

      \[\leadsto 100 \cdot \frac{{\color{blue}{\left(e^{\log \left(1 + \frac{i}{n}\right)}\right)}}^{n} - 1}{\frac{i}{n}}\]
    4. Applied pow-exp18.1

      \[\leadsto 100 \cdot \frac{\color{blue}{e^{\log \left(1 + \frac{i}{n}\right) \cdot n}} - 1}{\frac{i}{n}}\]
    5. Applied expm1-def2.0

      \[\leadsto 100 \cdot \frac{\color{blue}{(e^{\log \left(1 + \frac{i}{n}\right) \cdot n} - 1)^*}}{\frac{i}{n}}\]
    6. Simplified23.3

      \[\leadsto 100 \cdot \frac{(e^{\color{blue}{n \cdot \log_* (1 + \frac{i}{n})}} - 1)^*}{\frac{i}{n}}\]
    7. Using strategy rm
    8. Applied add-sqr-sqrt25.4

      \[\leadsto 100 \cdot \frac{(e^{n \cdot \log_* (1 + \frac{i}{n})} - 1)^*}{\color{blue}{\sqrt{\frac{i}{n}} \cdot \sqrt{\frac{i}{n}}}}\]
    9. Applied *-un-lft-identity25.4

      \[\leadsto 100 \cdot \frac{\color{blue}{1 \cdot (e^{n \cdot \log_* (1 + \frac{i}{n})} - 1)^*}}{\sqrt{\frac{i}{n}} \cdot \sqrt{\frac{i}{n}}}\]
    10. Applied times-frac25.4

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

    if -2.549728235978189e-174 < n < 5.831751074444269e-195

    1. Initial program 22.6

      \[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]
    2. Using strategy rm
    3. Applied add-exp-log22.6

      \[\leadsto 100 \cdot \frac{{\color{blue}{\left(e^{\log \left(1 + \frac{i}{n}\right)}\right)}}^{n} - 1}{\frac{i}{n}}\]
    4. Applied pow-exp22.6

      \[\leadsto 100 \cdot \frac{\color{blue}{e^{\log \left(1 + \frac{i}{n}\right) \cdot n}} - 1}{\frac{i}{n}}\]
    5. Applied expm1-def15.2

      \[\leadsto 100 \cdot \frac{\color{blue}{(e^{\log \left(1 + \frac{i}{n}\right) \cdot n} - 1)^*}}{\frac{i}{n}}\]
    6. Simplified15.0

      \[\leadsto 100 \cdot \frac{(e^{\color{blue}{n \cdot \log_* (1 + \frac{i}{n})}} - 1)^*}{\frac{i}{n}}\]
    7. Taylor expanded around 0 12.1

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

    if 5.831751074444269e-195 < n

    1. Initial program 57.2

      \[100 \cdot \frac{{\left(1 + \frac{i}{n}\right)}^{n} - 1}{\frac{i}{n}}\]
    2. Using strategy rm
    3. Applied add-exp-log57.2

      \[\leadsto 100 \cdot \frac{{\color{blue}{\left(e^{\log \left(1 + \frac{i}{n}\right)}\right)}}^{n} - 1}{\frac{i}{n}}\]
    4. Applied pow-exp57.2

      \[\leadsto 100 \cdot \frac{\color{blue}{e^{\log \left(1 + \frac{i}{n}\right) \cdot n}} - 1}{\frac{i}{n}}\]
    5. Applied expm1-def50.7

      \[\leadsto 100 \cdot \frac{\color{blue}{(e^{\log \left(1 + \frac{i}{n}\right) \cdot n} - 1)^*}}{\frac{i}{n}}\]
    6. Simplified15.5

      \[\leadsto 100 \cdot \frac{(e^{\color{blue}{n \cdot \log_* (1 + \frac{i}{n})}} - 1)^*}{\frac{i}{n}}\]
    7. Using strategy rm
    8. Applied add-sqr-sqrt15.8

      \[\leadsto 100 \cdot \color{blue}{\left(\sqrt{\frac{(e^{n \cdot \log_* (1 + \frac{i}{n})} - 1)^*}{\frac{i}{n}}} \cdot \sqrt{\frac{(e^{n \cdot \log_* (1 + \frac{i}{n})} - 1)^*}{\frac{i}{n}}}\right)}\]
    9. Applied associate-*r*15.8

      \[\leadsto \color{blue}{\left(100 \cdot \sqrt{\frac{(e^{n \cdot \log_* (1 + \frac{i}{n})} - 1)^*}{\frac{i}{n}}}\right) \cdot \sqrt{\frac{(e^{n \cdot \log_* (1 + \frac{i}{n})} - 1)^*}{\frac{i}{n}}}}\]
  3. Recombined 5 regimes into one program.
  4. Final simplification20.0

    \[\leadsto \begin{array}{l} \mathbf{if}\;n \le -8.764753048170504 \cdot 10^{+49}:\\ \;\;\;\;100 \cdot \frac{(e^{i} - 1)^*}{\frac{i}{n}}\\ \mathbf{elif}\;n \le -3.869064973251871 \cdot 10^{-99}:\\ \;\;\;\;\frac{\left({\left(\frac{i}{n} + 1\right)}^{n} - 1\right) \cdot 100}{\frac{i}{n}}\\ \mathbf{elif}\;n \le -2.549728235978189 \cdot 10^{-174}:\\ \;\;\;\;100 \cdot \left(\frac{(e^{\log_* (1 + \frac{i}{n}) \cdot n} - 1)^*}{\sqrt{\frac{i}{n}}} \cdot \frac{1}{\sqrt{\frac{i}{n}}}\right)\\ \mathbf{elif}\;n \le 5.831751074444269 \cdot 10^{-195}:\\ \;\;\;\;0\\ \mathbf{else}:\\ \;\;\;\;\sqrt{\frac{(e^{\log_* (1 + \frac{i}{n}) \cdot n} - 1)^*}{\frac{i}{n}}} \cdot \left(100 \cdot \sqrt{\frac{(e^{\log_* (1 + \frac{i}{n}) \cdot n} - 1)^*}{\frac{i}{n}}}\right)\\ \end{array}\]

Reproduce

herbie shell --seed 2018362 +o rules:numerics
(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))))

Details

Time bar (total: 23.0s)Debug log

start400.0ms

Algorithm
intervals

setup845.0ms

Pruning

2 alts after pruning (2 fresh and 0 done)

Merged error: 39.9b

localize34.0ms

Local error

Found 4 expressions with local error:

10.2b
(/ (- (pow (+ 1 (/ i n)) n) 1) (/ i n))
9.2b
(pow (+ 1 (/ i n)) n)
1.2b
(- (pow (+ 1 (/ i n)) n) 1)
0.1b
(* 100 (/ (- (pow (+ 1 (/ i n)) n) 1) (/ i n)))

rewrite87.0ms

Algorithm
rewrite-expression-head
Counts
4 → 122
Calls

4 calls. Slowest were:

37.0ms
(/ (- (pow (+ 1 (/ i n)) n) 1) (/ i n))
25.0ms
(- (pow (+ 1 (/ i n)) n) 1)
19.0ms
(* 100 (/ (- (pow (+ 1 (/ i n)) n) 1) (/ i n)))

series769.0ms

Counts
4 → 12
Calls

4 calls. Slowest were:

253.0ms
(* 100 (/ (- (pow (+ 1 (/ i n)) n) 1) (/ i n)))
224.0ms
(/ (- (pow (+ 1 (/ i n)) n) 1) (/ i n))
168.0ms
(- (pow (+ 1 (/ i n)) n) 1)
123.0ms
(pow (+ 1 (/ i n)) n)

simplify4.0s

Counts
105 → 134
Calls

105 calls. Slowest were:

420.0ms
(/ (* (* (- (pow (+ 1 (/ i n)) n) 1) (- (pow (+ 1 (/ i n)) n) 1)) (- (pow (+ 1 (/ i n)) n) 1)) (* (* (/ i n) (/ i n)) (/ i n)))
326.0ms
(* 100 (/ (* n (- (exp (* n (- (log (/ -1 n)) (log (/ -1 i))))) 1)) i))
291.0ms
(/ (* (- (exp (* (- (log (/ 1 n)) (log (/ 1 i))) n)) 1) n) i)

prune1.6s

Pruning

7 alts after pruning (7 fresh and 0 done)

Merged error: 9.7b

localize27.0ms

Local error

Found 4 expressions with local error:

10.1b
(* n (log1p (/ i n)))
10.1b
(/ (expm1 (* n (log1p (/ i n)))) (/ i n))
9.0b
(log1p (/ i n))
0.1b
(* 100 (/ (expm1 (* n (log1p (/ i n)))) (/ i n)))

rewrite15.0ms

Algorithm
rewrite-expression-head
Counts
4 → 87
Calls

4 calls. Slowest were:

6.0ms
(/ (expm1 (* n (log1p (/ i n)))) (/ i n))
3.0ms
(* 100 (/ (expm1 (* n (log1p (/ i n)))) (/ i n)))
2.0ms
(* n (log1p (/ i n)))

series705.0ms

Counts
4 → 12
Calls

4 calls. Slowest were:

311.0ms
(/ (expm1 (* n (log1p (/ i n)))) (/ i n))
288.0ms
(* 100 (/ (expm1 (* n (log1p (/ i n)))) (/ i n)))
63.0ms
(* n (log1p (/ i n)))
42.0ms
(log1p (/ i n))

simplify1.1s

Counts
66 → 99
Calls

66 calls. Slowest were:

235.0ms
(/ (* (* (expm1 (* n (log1p (/ i n)))) (expm1 (* n (log1p (/ i n))))) (expm1 (* n (log1p (/ i n))))) (* (* (/ i n) (/ i n)) (/ i n)))
80.0ms
(/ (* (- (* 100 (exp i)) 100) n) i)
79.0ms
(- (log (/ -1 n)) (log (/ -1 i)))

prune1.1s

Pruning

12 alts after pruning (12 fresh and 0 done)

Merged error: 9.6b

localize16.0ms

Local error

Found 4 expressions with local error:

19.3b
(cbrt (/ i n))
19.3b
(cbrt (/ i n))
19.3b
(cbrt (/ i n))
10.1b
(* n (log1p (/ i n)))

rewrite3.0ms

Algorithm
rewrite-expression-head
Counts
4 → 58
Calls

4 calls. Slowest were:

1.0ms
(* n (log1p (/ i n)))
1.0ms
(cbrt (/ i n))
0.0ms
(cbrt (/ i n))

series284.0ms

Counts
4 → 12
Calls

4 calls. Slowest were:

91.0ms
(cbrt (/ i n))
70.0ms
(cbrt (/ i n))
62.0ms
(* n (log1p (/ i n)))
61.0ms
(cbrt (/ i n))

simplify1.4s

Counts
30 → 70
Calls

30 calls. Slowest were:

232.0ms
(exp (* 1/3 (- (log (/ 1 n)) (log (/ 1 i)))))
215.0ms
(exp (* 1/3 (- (log (/ 1 n)) (log (/ 1 i)))))
178.0ms
(exp (* 1/3 (- (log (/ 1 n)) (log (/ 1 i)))))

prune1.1s

Pruning

12 alts after pruning (11 fresh and 1 done)

Merged error: 9.6b

localize18.0ms

Local error

Found 4 expressions with local error:

16.2b
(cbrt (/ (expm1 (* n (log1p (/ i n)))) (/ i n)))
16.2b
(cbrt (/ (expm1 (* n (log1p (/ i n)))) (/ i n)))
16.2b
(cbrt (/ (expm1 (* n (log1p (/ i n)))) (/ i n)))
10.1b
(* n (log1p (/ i n)))

rewrite8.0ms

Algorithm
rewrite-expression-head
Counts
4 → 97
Calls

4 calls. Slowest were:

2.0ms
(* n (log1p (/ i n)))
2.0ms
(cbrt (/ (expm1 (* n (log1p (/ i n)))) (/ i n)))
1.0ms
(cbrt (/ (expm1 (* n (log1p (/ i n)))) (/ i n)))

series3.5s

Counts
4 → 12
Calls

4 calls. Slowest were:

1.2s
(cbrt (/ (expm1 (* n (log1p (/ i n)))) (/ i n)))
1.1s
(cbrt (/ (expm1 (* n (log1p (/ i n)))) (/ i n)))
1.1s
(cbrt (/ (expm1 (* n (log1p (/ i n)))) (/ i n)))
62.0ms
(* n (log1p (/ i n)))

simplify2.6s

Counts
69 → 109
Calls

69 calls. Slowest were:

399.0ms
(exp (* 1/3 (- (+ (log (/ 1 i)) (log (- (exp i) 1))) (log (/ 1 n)))))
338.0ms
(exp (* 1/3 (- (+ (log (/ 1 i)) (log (- (exp i) 1))) (log (/ 1 n)))))
307.0ms
(exp (* 1/3 (- (+ (log (/ 1 i)) (log (- (exp i) 1))) (log (/ 1 n)))))

prune2.1s

Pruning

12 alts after pruning (10 fresh and 2 done)

Merged error: 9.6b

regimes307.0ms

Accuracy

8.2% (10.5b remaining)

Error of 20.0b against oracle of 9.5b and baseline of 20.9b

bsearch1000.0ms