Average Error: 45.8 → 0.0
Time: 2.9s
Precision: 64
Internal Precision: 128
\[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1.0}\]
\[\begin{array}{l} \mathbf{if}\;i \le 243.10396228585506:\\ \;\;\;\;\frac{\frac{i}{4} \cdot i}{i \cdot \left(4 \cdot i\right) - 1.0}\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{1}{16} + \frac{0.00390625}{{i}^{4}}\right) + \frac{\frac{0.015625}{i}}{i}\\ \end{array}\]

Error

Bits error versus i

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Split input into 2 regimes
  2. if i < 243.10396228585506

    1. Initial program 44.7

      \[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1.0}\]
    2. Simplified0.0

      \[\leadsto \color{blue}{\frac{i \cdot \frac{i}{4}}{i \cdot \left(4 \cdot i\right) - 1.0}}\]

    if 243.10396228585506 < i

    1. Initial program 46.8

      \[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1.0}\]
    2. Simplified30.6

      \[\leadsto \color{blue}{\frac{i \cdot \frac{i}{4}}{i \cdot \left(4 \cdot i\right) - 1.0}}\]
    3. Taylor expanded around -inf 0.0

      \[\leadsto \color{blue}{0.015625 \cdot \frac{1}{{i}^{2}} + \left(\frac{1}{16} + 0.00390625 \cdot \frac{1}{{i}^{4}}\right)}\]
    4. Simplified0.0

      \[\leadsto \color{blue}{\frac{\frac{0.015625}{i}}{i} + \left(\frac{1}{16} + \frac{0.00390625}{{i}^{4}}\right)}\]
  3. Recombined 2 regimes into one program.
  4. Final simplification0.0

    \[\leadsto \begin{array}{l} \mathbf{if}\;i \le 243.10396228585506:\\ \;\;\;\;\frac{\frac{i}{4} \cdot i}{i \cdot \left(4 \cdot i\right) - 1.0}\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{1}{16} + \frac{0.00390625}{{i}^{4}}\right) + \frac{\frac{0.015625}{i}}{i}\\ \end{array}\]

Reproduce

herbie shell --seed 2019008 
(FPCore (i)
  :name "Octave 3.8, jcobi/4, as called"
  :pre (and (> i 0))
  (/ (/ (* (* i i) (* i i)) (* (* 2 i) (* 2 i))) (- (* (* 2 i) (* 2 i)) 1.0)))

Details

Time bar (total: 2.7s)Debug log

sample50.0ms

Algorithm
intervals

simplify120.0ms

Counts
1 → 1
Calls

1 calls. Slowest were:

120.0ms
(/ (/ (* (* i i) (* i i)) (* (* 2 i) (* 2 i))) (- (* (* 2 i) (* 2 i)) 1.0))

prune12.0ms

Pruning

1 alts after pruning (1 fresh and 0 done)

Merged error: 15.5b

localize20.0ms

Local error

Found 1 expressions with local error:

15.5b
(/ (* i (/ i 4)) (- (* i (* 4 i)) 1.0))

rewrite9.0ms

Algorithm
rewrite-expression-head
Counts
1 → 22
Calls

1 calls. Slowest were:

9.0ms
(/ (* i (/ i 4)) (- (* i (* 4 i)) 1.0))

series36.0ms

Counts
1 → 3
Calls

1 calls. Slowest were:

36.0ms
(/ (* i (/ i 4)) (- (* i (* 4 i)) 1.0))

simplify706.0ms

Counts
17 → 25
Calls

17 calls. Slowest were:

162.0ms
(+ (* (* i (* 4 i)) (* i (* 4 i))) (+ (* 1.0 1.0) (* (* i (* 4 i)) 1.0)))
126.0ms
(- (+ (* 0.25 (pow i 2)) (+ (* 1.0 (pow i 4)) (* 4.0 (pow i 6)))))
103.0ms
(- (log (* i (/ i 4))) (log (- (* i (* 4 i)) 1.0)))

prune193.0ms

Pruning

2 alts after pruning (1 fresh and 1 done)

Merged error: 0b

localize16.0ms

Local error

Found 2 expressions with local error:

0.2b
(/ 0.00390625 (pow i 4))
0.1b
(/ (/ 0.015625 i) i)

rewrite4.0ms

Algorithm
rewrite-expression-head
Counts
2 → 28
Calls

2 calls. Slowest were:

3.0ms
(/ (/ 0.015625 i) i)
1.0ms
(/ 0.00390625 (pow i 4))

series45.0ms

Counts
2 → 6
Calls

2 calls. Slowest were:

27.0ms
(/ 0.00390625 (pow i 4))
18.0ms
(/ (/ 0.015625 i) i)

simplify17.0ms

Counts
11 → 34
Calls

11 calls. Slowest were:

3.0ms
(/ 0.015625 (pow i 2))
3.0ms
(/ 0.015625 (pow i 2))
3.0ms
(/ 0.015625 (pow i 2))

prune238.0ms

Pruning

2 alts after pruning (0 fresh and 2 done)

Merged error: 0b

regimes20.0ms

Accuracy

100% (0.0b remaining)

Error of 0.0b against oracle of 0.0b and baseline of 15.2b

bsearch64.0ms

end0.0ms

sample1.1s

Algorithm
intervals