Average Error: 46.0 → 0.0
Time: 4.9s
Precision: 64
Internal Precision: 128
\[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1.0}\]
\[\begin{array}{l} \mathbf{if}\;i \le 634.7968293108698:\\ \;\;\;\;\frac{\frac{i}{4} \cdot i}{i \cdot \left(4 \cdot i\right) - 1.0}\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{1}{16} + \frac{0.00390625}{{i}^{4}}\right) + \frac{\frac{0.015625}{i}}{i}\\ \end{array}\]

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 < 634.7968293108698

    1. Initial program 45.2

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

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

    if 634.7968293108698 < 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

    \[\leadsto \begin{array}{l} \mathbf{if}\;i \le 634.7968293108698:\\ \;\;\;\;\frac{\frac{i}{4} \cdot i}{i \cdot \left(4 \cdot i\right) - 1.0}\\ \mathbf{else}:\\ \;\;\;\;\left(\frac{1}{16} + \frac{0.00390625}{{i}^{4}}\right) + \frac{\frac{0.015625}{i}}{i}\\ \end{array}\]

Reproduce

herbie shell --seed 2019010 
(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: 4.7s)Debug log

sample40.0ms

Algorithm
intervals

simplify186.0ms

Counts
1 → 1
Calls
1 calls:
Slowest
186.0ms
(/ (/ (* (* i i) (* i i)) (* (* 2 i) (* 2 i))) (- (* (* 2 i) (* 2 i)) 1.0))

prune15.0ms

Pruning

1 alts after pruning (1 fresh and 0 done)

Merged error: 12.6b

localize33.0ms

Local error

Found 1 expressions with local error:

12.6b
(/ (* i (/ i 4)) (- (* i (* 4 i)) 1.0))

rewrite12.0ms

Algorithm
rewrite-expression-head
Rules
add-cube-cbrt
add-exp-log
add-cbrt-cube
times-frac
*-un-lft-identity
associate-/r*
add-sqr-sqrt
associate-/r/
associate-/l/
add-log-exp
associate-/l*
flip--
div-inv
associate-*r/
div-exp
flip3--
frac-2neg
clear-num
cbrt-undiv
pow1
Counts
1 → 22
Calls
1 calls:
Slowest
11.0ms
(/ (* i (/ i 4)) (- (* i (* 4 i)) 1.0))

series43.0ms

Counts
1 → 3
Calls
1 calls:
Slowest
43.0ms
(/ (* i (/ i 4)) (- (* i (* 4 i)) 1.0))

simplify729.0ms

Counts
17 → 25
Calls
17 calls:
Slowest
196.0ms
(+ (* (* i (* 4 i)) (* i (* 4 i))) (+ (* 1.0 1.0) (* (* i (* 4 i)) 1.0)))
115.0ms
(/ (* (* (* i (/ i 4)) (* i (/ i 4))) (* i (/ i 4))) (* (* (- (* i (* 4 i)) 1.0) (- (* i (* 4 i)) 1.0)) (- (* i (* 4 i)) 1.0)))
114.0ms
(- (+ (* 0.25 (pow i 2)) (+ (* 1.0 (pow i 4)) (* 4.0 (pow i 6)))))
101.0ms
(- (log (* i (/ i 4))) (log (- (* i (* 4 i)) 1.0)))
44.0ms
(+ (* 0.015625 (/ 1 (pow i 2))) (+ 1/16 (* 0.00390625 (/ 1 (pow i 4)))))

prune167.0ms

Pruning

2 alts after pruning (1 fresh and 1 done)

Merged error: 0b

localize31.0ms

Local error

Found 3 expressions with local error:

0.1b
(/ (/ 0.015625 i) i)
0.1b
(/ 0.00390625 (pow i 4))
0.0b
(+ (/ (/ 0.015625 i) i) (+ 1/16 (/ 0.00390625 (pow i 4))))

rewrite10.0ms

Algorithm
rewrite-expression-head
Rules
*-un-lft-identity
add-log-exp
add-cube-cbrt
add-sqr-sqrt
associate-/l*
div-inv
add-exp-log
add-cbrt-cube
associate-/r*
pow1
flip-+
frac-add
flip3-+
frac-2neg
clear-num
associate-/l/
distribute-lft-out
sum-log
associate-+r+
+-commutative
Counts
3 → 43
Calls
3 calls:
Slowest
6.0ms
(+ (/ (/ 0.015625 i) i) (+ 1/16 (/ 0.00390625 (pow i 4))))
2.0ms
(/ (/ 0.015625 i) i)
0.0ms
(/ 0.00390625 (pow i 4))

series62.0ms

Counts
3 → 9
Calls
3 calls:
Slowest
33.0ms
(+ (/ (/ 0.015625 i) i) (+ 1/16 (/ 0.00390625 (pow i 4))))
18.0ms
(/ 0.00390625 (pow i 4))
11.0ms
(/ (/ 0.015625 i) i)

simplify816.0ms

Counts
21 → 52
Calls
21 calls:
Slowest
293.0ms
(* i (+ (* 1/16 1/16) (- (* (/ 0.00390625 (pow i 4)) (/ 0.00390625 (pow i 4))) (* 1/16 (/ 0.00390625 (pow i 4))))))
164.0ms
(+ (* (/ 0.015625 i) (- 1/16 (/ 0.00390625 (pow i 4)))) (* i (- (* 1/16 1/16) (* (/ 0.00390625 (pow i 4)) (/ 0.00390625 (pow i 4))))))
104.0ms
(+ (* (/ 0.015625 i) (+ (* 1/16 1/16) (- (* (/ 0.00390625 (pow i 4)) (/ 0.00390625 (pow i 4))) (* 1/16 (/ 0.00390625 (pow i 4)))))) (* i (+ (pow 1/16 3) (pow (/ 0.00390625 (pow i 4)) 3))))
59.0ms
(+ (* 0.015625 (/ 1 (pow i 2))) (+ 1/16 (* 0.00390625 (/ 1 (pow i 4)))))
55.0ms
(+ (* 0.015625 (/ 1 (pow i 2))) (+ 1/16 (* 0.00390625 (/ 1 (pow i 4)))))

prune454.0ms

Pruning

2 alts after pruning (0 fresh and 2 done)

Merged error: 0b

regimes41.0ms

Accuracy

100% (0.0b remaining)

Error of 0.0b against oracle of 0.0b and baseline of 15.1b

bsearch89.0ms

end0.0ms

sample1.9s

Algorithm
intervals