Average Error: 1.0 → 0.0
Time: 53.4s
Precision: 64
Internal Precision: 128
\[\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}\]
\[\frac{1}{\frac{\sqrt{(-6 \cdot \left(v \cdot v\right) + 2)_*}}{\frac{1}{\sqrt{1 - v \cdot v}} \cdot \frac{\frac{\frac{4}{3}}{\pi}}{\sqrt{1 - v \cdot v}}}}\]

Error

Bits error versus v

Derivation

  1. Initial program 1.0

    \[\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}\]
  2. Simplified0.0

    \[\leadsto \color{blue}{\frac{\frac{\frac{\frac{4}{3}}{\pi}}{1 - v \cdot v}}{\sqrt{(-6 \cdot \left(v \cdot v\right) + 2)_*}}}\]
  3. Using strategy rm
  4. Applied add-sqr-sqrt0.0

    \[\leadsto \frac{\frac{\frac{\frac{4}{3}}{\pi}}{\color{blue}{\sqrt{1 - v \cdot v} \cdot \sqrt{1 - v \cdot v}}}}{\sqrt{(-6 \cdot \left(v \cdot v\right) + 2)_*}}\]
  5. Applied *-un-lft-identity0.0

    \[\leadsto \frac{\frac{\color{blue}{1 \cdot \frac{\frac{4}{3}}{\pi}}}{\sqrt{1 - v \cdot v} \cdot \sqrt{1 - v \cdot v}}}{\sqrt{(-6 \cdot \left(v \cdot v\right) + 2)_*}}\]
  6. Applied times-frac0.0

    \[\leadsto \frac{\color{blue}{\frac{1}{\sqrt{1 - v \cdot v}} \cdot \frac{\frac{\frac{4}{3}}{\pi}}{\sqrt{1 - v \cdot v}}}}{\sqrt{(-6 \cdot \left(v \cdot v\right) + 2)_*}}\]
  7. Using strategy rm
  8. Applied clear-num0.0

    \[\leadsto \color{blue}{\frac{1}{\frac{\sqrt{(-6 \cdot \left(v \cdot v\right) + 2)_*}}{\frac{1}{\sqrt{1 - v \cdot v}} \cdot \frac{\frac{\frac{4}{3}}{\pi}}{\sqrt{1 - v \cdot v}}}}}\]
  9. Final simplification0.0

    \[\leadsto \frac{1}{\frac{\sqrt{(-6 \cdot \left(v \cdot v\right) + 2)_*}}{\frac{1}{\sqrt{1 - v \cdot v}} \cdot \frac{\frac{\frac{4}{3}}{\pi}}{\sqrt{1 - v \cdot v}}}}\]

Reproduce

herbie shell --seed 2019005 +o rules:numerics
(FPCore (v)
  :name "Falkner and Boettcher, Equation (22+)"
  (/ 4 (* (* (* 3 PI) (- 1 (* v v))) (sqrt (- 2 (* 6 (* v v)))))))

Details

Time bar (total: 53.1s)Debug log

sample102.0ms

Algorithm
intervals

simplify99.0ms

Counts
1 → 1
Calls

1 calls. Slowest were:

98.0ms
(/ 4 (* (* (* 3 PI) (- 1 (* v v))) (sqrt (- 2 (* 6 (* v v))))))

prune12.0ms

Pruning

2 alts after pruning (2 fresh and 0 done)

Merged error: 0.0b

localize22.0ms

Local error

Found 4 expressions with local error:

1.0b
(/ 4/3 PI)
0.0b
(/ (/ 4/3 PI) (- 1 (* v v)))
0.0b
(sqrt (fma -6 (* v v) 2))
0.0b
(/ (/ (/ 4/3 PI) (- 1 (* v v))) (sqrt (fma -6 (* v v) 2)))

rewrite14.0ms

Algorithm
rewrite-expression-head
Counts
4 → 211
Calls

4 calls. Slowest were:

6.0ms
(/ (/ (/ 4/3 PI) (- 1 (* v v))) (sqrt (fma -6 (* v v) 2)))
3.0ms
(/ (/ 4/3 PI) (- 1 (* v v)))
1.0ms
(sqrt (fma -6 (* v v) 2))

series257.0ms

Counts
4 → 10
Calls

4 calls. Slowest were:

170.0ms
(/ (/ (/ 4/3 PI) (- 1 (* v v))) (sqrt (fma -6 (* v v) 2)))
61.0ms
(/ (/ 4/3 PI) (- 1 (* v v)))
26.0ms
(sqrt (fma -6 (* v v) 2))
0.0ms
(/ 4/3 PI)

simplify24.3s

Counts
291 → 221
Calls

291 calls. Slowest were:

804.0ms
(- (+ (* 4/3 (/ 1 (* (pow v 2) PI))) (+ (* 4/3 (/ 1 (* (pow v 4) PI))) (* 4/3 (/ 1 (* (pow v 6) PI))))))
721.0ms
(- (+ (* 4/3 (/ 1 (* (pow v 2) PI))) (+ (* 4/3 (/ 1 (* (pow v 4) PI))) (* 4/3 (/ 1 (* (pow v 6) PI))))))
469.0ms
(/ (/ (/ 4/3 PI) (- (pow 1 3) (pow (* v v) 3))) 1)

prune2.5s

Pruning

2 alts after pruning (2 fresh and 0 done)

Merged error: 0b

localize18.0ms

Local error

Found 4 expressions with local error:

1.0b
(/ 4/3 PI)
0.0b
(/ (/ 4/3 PI) (sqrt (- 1 (* v v))))
0.0b
(* (/ 1 (sqrt (- 1 (* v v)))) (/ (/ 4/3 PI) (sqrt (- 1 (* v v)))))
0.0b
(/ (* (/ 1 (sqrt (- 1 (* v v)))) (/ (/ 4/3 PI) (sqrt (- 1 (* v v))))) (sqrt (fma -6 (* v v) 2)))

rewrite27.0ms

Algorithm
rewrite-expression-head
Counts
4 → 155
Calls

4 calls. Slowest were:

13.0ms
(/ (* (/ 1 (sqrt (- 1 (* v v)))) (/ (/ 4/3 PI) (sqrt (- 1 (* v v))))) (sqrt (fma -6 (* v v) 2)))
7.0ms
(* (/ 1 (sqrt (- 1 (* v v)))) (/ (/ 4/3 PI) (sqrt (- 1 (* v v)))))
3.0ms
(/ (/ 4/3 PI) (sqrt (- 1 (* v v))))

series449.0ms

Counts
4 → 10
Calls

4 calls. Slowest were:

225.0ms
(/ (* (/ 1 (sqrt (- 1 (* v v)))) (/ (/ 4/3 PI) (sqrt (- 1 (* v v))))) (sqrt (fma -6 (* v v) 2)))
136.0ms
(/ (/ 4/3 PI) (sqrt (- 1 (* v v))))
88.0ms
(* (/ 1 (sqrt (- 1 (* v v)))) (/ (/ 4/3 PI) (sqrt (- 1 (* v v)))))
0.0ms
(/ 4/3 PI)

simplify9.2s

Counts
146 → 165
Calls

146 calls. Slowest were:

748.0ms
(- (+ (* 4/3 (/ 1 (* (pow v 2) PI))) (+ (* 4/3 (/ 1 (* (pow v 4) PI))) (* 4/3 (/ 1 (* (pow v 6) PI))))))
615.0ms
(- (+ (* 4/3 (/ 1 (* (pow v 2) PI))) (+ (* 4/3 (/ 1 (* (pow v 4) PI))) (* 4/3 (/ 1 (* (pow v 6) PI))))))
505.0ms
(- (* 4/3 (/ (sqrt -1) (* v PI))) (+ (* 2/3 (/ 1 (* (pow v 5) (* (sqrt -1) PI)))) (+ (* 2/3 (/ 1 (* (pow v 3) (* (sqrt -1) PI)))) (* 1/6 (/ 1 (* (pow v 5) (* (pow (sqrt -1) 3) PI)))))))

prune1.8s

Pruning

1 alts after pruning (1 fresh and 0 done)

Merged error: 0b

localize7.0ms

Local error

Found 4 expressions with local error:

1.0b
(/ 4/3 PI)
1.0b
(/ 1 (/ (sqrt (fma -6 (* v v) 2)) (* (/ 1 (sqrt (- 1 (* v v)))) (/ (/ 4/3 PI) (sqrt (- 1 (* v v)))))))
0.0b
(/ (/ 4/3 PI) (sqrt (- 1 (* v v))))
0.0b
(/ (sqrt (fma -6 (* v v) 2)) (* (/ 1 (sqrt (- 1 (* v v)))) (/ (/ 4/3 PI) (sqrt (- 1 (* v v))))))

rewrite26.0ms

Algorithm
rewrite-expression-head
Counts
4 → 133
Calls

4 calls. Slowest were:

14.0ms
(/ (sqrt (fma -6 (* v v) 2)) (* (/ 1 (sqrt (- 1 (* v v)))) (/ (/ 4/3 PI) (sqrt (- 1 (* v v))))))
5.0ms
(/ 1 (/ (sqrt (fma -6 (* v v) 2)) (* (/ 1 (sqrt (- 1 (* v v)))) (/ (/ 4/3 PI) (sqrt (- 1 (* v v)))))))
4.0ms
(/ (/ 4/3 PI) (sqrt (- 1 (* v v))))

series587.0ms

Counts
4 → 10
Calls

4 calls. Slowest were:

239.0ms
(/ 1 (/ (sqrt (fma -6 (* v v) 2)) (* (/ 1 (sqrt (- 1 (* v v)))) (/ (/ 4/3 PI) (sqrt (- 1 (* v v)))))))
182.0ms
(/ (/ 4/3 PI) (sqrt (- 1 (* v v))))
166.0ms
(/ (sqrt (fma -6 (* v v) 2)) (* (/ 1 (sqrt (- 1 (* v v)))) (/ (/ 4/3 PI) (sqrt (- 1 (* v v))))))
0.0ms
(/ 4/3 PI)

simplify8.8s

Counts
113 → 143
Calls

113 calls. Slowest were:

757.0ms
(cbrt (/ (sqrt (fma -6 (* v v) 2)) (* (/ 1 (sqrt (- 1 (* v v)))) (/ (/ 4/3 PI) (sqrt (- 1 (* v v)))))))
531.0ms
(- (* 4/3 (/ (sqrt -1) (* v PI))) (+ (* 2/3 (/ 1 (* (pow v 5) (* (sqrt -1) PI)))) (+ (* 2/3 (/ 1 (* (pow v 3) (* (sqrt -1) PI)))) (* 1/6 (/ 1 (* (pow v 5) (* (pow (sqrt -1) 3) PI)))))))
523.0ms
(/ 1 (* (/ 1 (sqrt (- 1 (* v v)))) (/ (/ 4/3 PI) (sqrt (- 1 (* v v))))))

prune1.9s

Pruning

1 alts after pruning (0 fresh and 1 done)

Merged error: 0b

end0.0ms

sample3.1s

Algorithm
intervals