Average Error: 13.9 → 1.5
Time: 4.8s
Precision: 64
Internal Precision: 128
\[x \cdot \frac{\frac{y}{z} \cdot t}{t}\]
\[\begin{array}{l} \mathbf{if}\;\frac{y}{z} \le -5.897662964381415 \cdot 10^{+305}:\\ \;\;\;\;\frac{y}{\frac{z}{x}}\\ \mathbf{elif}\;\frac{y}{z} \le -2.537105397623105 \cdot 10^{-218}:\\ \;\;\;\;\frac{x}{\frac{z}{y}}\\ \mathbf{elif}\;\frac{y}{z} \le 1.4297097965547508 \cdot 10^{-295}:\\ \;\;\;\;\frac{y}{\frac{z}{x}}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{\frac{z}{y}}\\ \end{array}\]

Error

Bits error versus x

Bits error versus y

Bits error versus z

Bits error versus t

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Split input into 2 regimes
  2. if (/ y z) < -5.897662964381415e+305 or -2.537105397623105e-218 < (/ y z) < 1.4297097965547508e-295

    1. Initial program 22.4

      \[x \cdot \frac{\frac{y}{z} \cdot t}{t}\]
    2. Simplified0.2

      \[\leadsto \color{blue}{y \cdot \frac{x}{z}}\]
    3. Using strategy rm
    4. Applied associate-*r/0.3

      \[\leadsto \color{blue}{\frac{y \cdot x}{z}}\]
    5. Using strategy rm
    6. Applied associate-/l*0.2

      \[\leadsto \color{blue}{\frac{y}{\frac{z}{x}}}\]

    if -5.897662964381415e+305 < (/ y z) < -2.537105397623105e-218 or 1.4297097965547508e-295 < (/ y z)

    1. Initial program 11.3

      \[x \cdot \frac{\frac{y}{z} \cdot t}{t}\]
    2. Simplified8.0

      \[\leadsto \color{blue}{y \cdot \frac{x}{z}}\]
    3. Using strategy rm
    4. Applied div-inv8.0

      \[\leadsto y \cdot \color{blue}{\left(x \cdot \frac{1}{z}\right)}\]
    5. Applied associate-*r*7.7

      \[\leadsto \color{blue}{\left(y \cdot x\right) \cdot \frac{1}{z}}\]
    6. Using strategy rm
    7. Applied pow17.7

      \[\leadsto \left(y \cdot x\right) \cdot \color{blue}{{\left(\frac{1}{z}\right)}^{1}}\]
    8. Applied pow17.7

      \[\leadsto \color{blue}{{\left(y \cdot x\right)}^{1}} \cdot {\left(\frac{1}{z}\right)}^{1}\]
    9. Applied pow-prod-down7.7

      \[\leadsto \color{blue}{{\left(\left(y \cdot x\right) \cdot \frac{1}{z}\right)}^{1}}\]
    10. Simplified1.9

      \[\leadsto {\color{blue}{\left(\frac{x}{\frac{z}{y}}\right)}}^{1}\]
  3. Recombined 2 regimes into one program.
  4. Final simplification1.5

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{y}{z} \le -5.897662964381415 \cdot 10^{+305}:\\ \;\;\;\;\frac{y}{\frac{z}{x}}\\ \mathbf{elif}\;\frac{y}{z} \le -2.537105397623105 \cdot 10^{-218}:\\ \;\;\;\;\frac{x}{\frac{z}{y}}\\ \mathbf{elif}\;\frac{y}{z} \le 1.4297097965547508 \cdot 10^{-295}:\\ \;\;\;\;\frac{y}{\frac{z}{x}}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{\frac{z}{y}}\\ \end{array}\]

Reproduce

herbie shell --seed 2019016 +o rules:numerics
(FPCore (x y z t)
  :name "Graphics.Rendering.Chart.Backend.Diagrams:calcFontMetrics from Chart-diagrams-1.5.1"
  (* x (/ (* (/ y z) t) t)))

Details

Time bar (total: 4.2s)Debug log

sample63.0ms

Algorithm
intervals
Results
315×(pre true 80)
315×(body real 80)

simplify296.0ms

Counts
1 → 1
Calls
1 calls:
Slowest
296.0ms
(* x (/ (* (/ y z) t) t))

prune11.0ms

Pruning

2 alts after pruning (2 fresh and 0 done)

Merged error: 0.3b

localize7.0ms

Local error

Found 1 expressions with local error:

7.0b
(* y (/ x z))

rewrite1.0ms

Algorithm
rewrite-expression-head
Rules
associate-*r*
add-cube-cbrt
*-un-lft-identity
add-sqr-sqrt
add-log-exp
div-inv
log1p-expm1-u
*-commutative
add-exp-log
associate-*r/
add-cbrt-cube
pow1
expm1-log1p-u
Counts
1 → 15
Calls
1 calls:
Slowest
1.0ms
(* y (/ x z))

series14.0ms

Counts
1 → 3
Calls
1 calls:
Slowest
14.0ms
(* y (/ x z))

simplify36.0ms

Counts
7 → 18
Calls
7 calls:
Slowest
11.0ms
(/ (* x y) z)
9.0ms
(/ (* x y) z)
8.0ms
(/ (* x y) z)
3.0ms
(/ 1 z)
2.0ms
(cbrt (/ x z))

prune129.0ms

Pruning

7 alts after pruning (6 fresh and 1 done)

Merged error: 0.0b

localize5.0ms

Local error

Found 1 expressions with local error:

5.4b
(/ (* y x) z)

rewrite3.0ms

Algorithm
rewrite-expression-head
Rules
add-log-exp
associate-/l*
div-inv
log1p-expm1-u
add-cube-cbrt
add-exp-log
add-cbrt-cube
*-un-lft-identity
frac-2neg
clear-num
pow1
expm1-log1p-u
add-sqr-sqrt
Counts
1 → 13
Calls
1 calls:
Slowest
2.0ms
(/ (* y x) z)

series17.0ms

Counts
1 → 3
Calls
1 calls:
Slowest
17.0ms
(/ (* y x) z)

simplify33.0ms

Counts
3 → 16
Calls
3 calls:
Slowest
11.0ms
(/ (* x y) z)
11.0ms
(/ (* x y) z)
10.0ms
(/ (* x y) z)

prune165.0ms

Pruning

6 alts after pruning (5 fresh and 1 done)

Merged error: 0.0b

localize11.0ms

Local error

Found 1 expressions with local error:

5.4b
(* (* y x) (/ 1 z))

rewrite7.0ms

Algorithm
rewrite-expression-head
Rules
associate-*r*
add-exp-log
add-cbrt-cube
pow1
add-cube-cbrt
*-un-lft-identity
add-sqr-sqrt
add-log-exp
div-inv
log1p-expm1-u
cbrt-unprod
*-commutative
un-div-inv
associate-*r/
prod-exp
pow-prod-down
associate-*l*
expm1-log1p-u
Counts
1 → 20
Calls
1 calls:
Slowest
7.0ms
(* (* y x) (/ 1 z))

series21.0ms

Counts
1 → 3
Calls
1 calls:
Slowest
21.0ms
(* (* y x) (/ 1 z))

simplify613.0ms

Counts
10 → 23
Calls
10 calls:
Slowest
477.0ms
(* (* (* (* y x) (* y x)) (* y x)) (* (* (/ 1 z) (/ 1 z)) (/ 1 z)))
60.0ms
(+ (log (* y x)) (log (/ 1 z)))
31.0ms
(* (* y x) (/ 1 z))
11.0ms
(/ (* x y) z)
10.0ms
(/ (* x y) z)

prune193.0ms

Pruning

6 alts after pruning (5 fresh and 1 done)

Merged error: 0.0b

localize13.0ms

Local error

Found 1 expressions with local error:

5.2b
(/ x (/ z y))

rewrite1.0ms

Algorithm
rewrite-expression-head
Rules
associate-/r*
div-inv
add-cube-cbrt
*-un-lft-identity
add-sqr-sqrt
add-log-exp
log1p-expm1-u
associate-/r/
add-exp-log
add-cbrt-cube
frac-2neg
clear-num
pow1
expm1-log1p-u
Counts
1 → 17
Calls
1 calls:
Slowest
1.0ms
(/ x (/ z y))

series24.0ms

Counts
1 → 3
Calls
1 calls:
Slowest
24.0ms
(/ x (/ z y))

simplify41.0ms

Counts
7 → 20
Calls
7 calls:
Slowest
13.0ms
(/ (* x y) z)
10.0ms
(/ (* x y) z)
10.0ms
(/ (* x y) z)
2.0ms
(/ 1 y)
2.0ms
(cbrt (/ z y))

prune167.0ms

Pruning

6 alts after pruning (4 fresh and 2 done)

Merged error: 0.0b

regimes485.0ms

Accuracy

74.4% (1.5b remaining)

Error of 1.5b against oracle of 0.0b and baseline of 5.8b

bsearch6.0ms

end0.0ms

sample1.8s

Algorithm
intervals
Results
9609×(pre true 80)
9609×(body real 80)