Average Error: 46.0 → 0.3
Time: 11.6s
Precision: 64
Internal Precision: 128
\[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1.0}\]
\[\frac{1}{16 - \frac{4.0}{i \cdot i}}\]

Error

Bits error versus i

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Initial program 46.0

    \[\frac{\frac{\left(i \cdot i\right) \cdot \left(i \cdot i\right)}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right)}}{\left(2 \cdot i\right) \cdot \left(2 \cdot i\right) - 1.0}\]
  2. Initial simplification16.0

    \[\leadsto \frac{i \cdot \frac{i}{4}}{i \cdot \left(4 \cdot i\right) - 1.0}\]
  3. Using strategy rm
  4. Applied clear-num16.3

    \[\leadsto \color{blue}{\frac{1}{\frac{i \cdot \left(4 \cdot i\right) - 1.0}{i \cdot \frac{i}{4}}}}\]
  5. Taylor expanded around inf 0.3

    \[\leadsto \frac{1}{\color{blue}{16 - 4.0 \cdot \frac{1}{{i}^{2}}}}\]
  6. Simplified0.3

    \[\leadsto \frac{1}{\color{blue}{16 - \frac{4.0}{i \cdot i}}}\]
  7. Final simplification0.3

    \[\leadsto \frac{1}{16 - \frac{4.0}{i \cdot i}}\]

Reproduce

herbie shell --seed 2018360 
(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: 8.9s)Debug log

start50.0ms

Algorithm
intervals

setup228.0ms

Pruning

2 alts after pruning (2 fresh and 0 done)

Merged error: 16.2b

localize15.0ms

Local error

Found 1 expressions with local error:

16.2b
(/ (* i (/ i 4)) (- (* i (* 4 i)) 1.0))

rewrite6.0ms

Algorithm
rewrite-expression-head
Counts
1 → 22
Calls

1 calls. Slowest were:

5.0ms
(/ (* i (/ i 4)) (- (* i (* 4 i)) 1.0))

series42.0ms

Counts
1 → 3
Calls

1 calls. Slowest were:

42.0ms
(/ (* i (/ i 4)) (- (* i (* 4 i)) 1.0))

simplify841.0ms

Counts
17 → 25
Calls

17 calls. Slowest were:

140.0ms
(- (log (* i (/ i 4))) (log (- (* i (* 4 i)) 1.0)))
138.0ms
(+ (* (* i (* 4 i)) (* i (* 4 i))) (+ (* 1.0 1.0) (* (* i (* 4 i)) 1.0)))
132.0ms
(/ (* (* (* i (/ i 4)) (* i (/ i 4))) (* i (/ i 4))) (* (* (- (* i (* 4 i)) 1.0) (- (* i (* 4 i)) 1.0)) (- (* i (* 4 i)) 1.0)))

prune227.0ms

Pruning

3 alts after pruning (3 fresh and 0 done)

Merged error: 0b

localize11.0ms

Local error

Found 2 expressions with local error:

15.6b
(/ (/ i 4) (- (* i (* 4 i)) 1.0))
0.1b
(* i (/ (/ i 4) (- (* i (* 4 i)) 1.0)))

rewrite20.0ms

Algorithm
rewrite-expression-head
Counts
2 → 61
Calls

2 calls. Slowest were:

10.0ms
(/ (/ i 4) (- (* i (* 4 i)) 1.0))
8.0ms
(* i (/ (/ i 4) (- (* i (* 4 i)) 1.0)))

series80.0ms

Counts
2 → 6
Calls

2 calls. Slowest were:

45.0ms
(* i (/ (/ i 4) (- (* i (* 4 i)) 1.0)))
34.0ms
(/ (/ i 4) (- (* i (* 4 i)) 1.0))

simplify2.1s

Counts
58 → 67
Calls

58 calls. Slowest were:

362.0ms
(/ (* (* (/ i 4) (/ i 4)) (/ i 4)) (* (* (- (* i (* 4 i)) 1.0) (- (* i (* 4 i)) 1.0)) (- (* i (* 4 i)) 1.0)))
178.0ms
(+ (* (* i (* 4 i)) (* i (* 4 i))) (+ (* 1.0 1.0) (* (* i (* 4 i)) 1.0)))
158.0ms
(+ (* (* i (* 4 i)) (* i (* 4 i))) (+ (* 1.0 1.0) (* (* i (* 4 i)) 1.0)))

prune649.0ms

Pruning

3 alts after pruning (2 fresh and 1 done)

Merged error: 0b

localize6.0ms

Local error

Found 2 expressions with local error:

16.3b
(/ (- (* i (* 4 i)) 1.0) (* i (/ i 4)))
0.2b
(/ 1 (/ (- (* i (* 4 i)) 1.0) (* i (/ i 4))))

rewrite8.0ms

Algorithm
rewrite-expression-head
Counts
2 → 46
Calls

2 calls. Slowest were:

6.0ms
(/ (- (* i (* 4 i)) 1.0) (* i (/ i 4)))
2.0ms
(/ 1 (/ (- (* i (* 4 i)) 1.0) (* i (/ i 4))))

series90.0ms

Counts
2 → 6
Calls

2 calls. Slowest were:

62.0ms
(/ (- (* i (* 4 i)) 1.0) (* i (/ i 4)))
28.0ms
(/ 1 (/ (- (* i (* 4 i)) 1.0) (* i (/ i 4))))

simplify3.2s

Counts
29 → 52
Calls

29 calls. Slowest were:

574.0ms
(/ (- (* i (* 4 i)) 1.0) (* i (/ i 4)))
296.0ms
(- (* (* i (* 4 i)) (* i (* 4 i))) (* 1.0 1.0))
280.0ms
(- (pow (* i (* 4 i)) 3) (pow 1.0 3))

prune514.0ms

Pruning

2 alts after pruning (1 fresh and 1 done)

Merged error: 0b

localize10.0ms

Local error

Found 2 expressions with local error:

0.5b
(/ 4.0 (* i i))
0.2b
(/ 1 (- 16 (/ 4.0 (* i i))))

rewrite4.0ms

Algorithm
rewrite-expression-head
Counts
2 → 29
Calls

2 calls. Slowest were:

1.0ms
(/ 1 (- 16 (/ 4.0 (* i i))))
0.0ms
(/ 4.0 (* i i))

series30.0ms

Counts
2 → 6
Calls

2 calls. Slowest were:

19.0ms
(/ 1 (- 16 (/ 4.0 (* i i))))
11.0ms
(/ 4.0 (* i i))

simplify377.0ms

Counts
12 → 35
Calls

12 calls. Slowest were:

149.0ms
(+ (* 16 16) (+ (* (/ 4.0 (* i i)) (/ 4.0 (* i i))) (* 16 (/ 4.0 (* i i)))))
100.0ms
(- (+ (* 0.25 (pow i 2)) (+ (* 1.0 (pow i 4)) (* 4.0 (pow i 6)))))
45.0ms
(+ (* 0.015625 (/ 1 (pow i 2))) (+ 1/16 (* 0.00390625 (/ 1 (pow i 4)))))

prune383.0ms

Pruning

2 alts after pruning (0 fresh and 2 done)

Merged error: 0b

regimes24.0ms

Accuracy

0% (0.3b remaining)

Error of 0.3b against oracle of 0.0b and baseline of 0.3b

bsearch2.0ms