Average Error: 0.4 → 0.6
Time: 33.3s
Precision: 64
Internal Precision: 320
\[\left(\frac{1}{6} \cdot {\left(-2 \cdot \log u1\right)}^{0.5}\right) \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right) + 0.5\]
\[e^{\log \left((\left(\cos \left(\left(u2 \cdot 2\right) \cdot \pi\right) \cdot {\left({\left(\log u1\right)}^{1.0} \cdot {-2}^{1.0}\right)}^{0.5}\right) \cdot \frac{1}{6} + 0.5)_*\right)}\]

Error

Bits error versus u1

Bits error versus u2

Derivation

  1. Initial program 0.4

    \[\left(\frac{1}{6} \cdot {\left(-2 \cdot \log u1\right)}^{0.5}\right) \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right) + 0.5\]
  2. Initial simplification0.4

    \[\leadsto (\left(\cos \left(\pi \cdot \left(2 \cdot u2\right)\right)\right) \cdot \left({\left(-2 \cdot \log u1\right)}^{0.5} \cdot \frac{1}{6}\right) + 0.5)_*\]
  3. Taylor expanded around -inf 62.0

    \[\leadsto \color{blue}{\frac{1}{6} \cdot \left({\left({\left(\log -1 - \log \left(\frac{-1}{u1}\right)\right)}^{1.0} \cdot {-2}^{1.0}\right)}^{0.5} \cdot \cos \left(2 \cdot \left(u2 \cdot \pi\right)\right)\right) + 0.5}\]
  4. Simplified0.4

    \[\leadsto \color{blue}{(\left({\left({\left(\log u1\right)}^{1.0} \cdot {-2}^{1.0}\right)}^{0.5} \cdot \cos \left(\left(u2 \cdot 2\right) \cdot \pi\right)\right) \cdot \frac{1}{6} + 0.5)_*}\]
  5. Using strategy rm
  6. Applied add-exp-log0.6

    \[\leadsto \color{blue}{e^{\log \left((\left({\left({\left(\log u1\right)}^{1.0} \cdot {-2}^{1.0}\right)}^{0.5} \cdot \cos \left(\left(u2 \cdot 2\right) \cdot \pi\right)\right) \cdot \frac{1}{6} + 0.5)_*\right)}}\]
  7. Final simplification0.6

    \[\leadsto e^{\log \left((\left(\cos \left(\left(u2 \cdot 2\right) \cdot \pi\right) \cdot {\left({\left(\log u1\right)}^{1.0} \cdot {-2}^{1.0}\right)}^{0.5}\right) \cdot \frac{1}{6} + 0.5)_*\right)}\]

Runtime

Time bar (total: 33.3s)Debug logProfile

herbie shell --seed 2018254 +o rules:numerics
(FPCore (u1 u2)
  :name "normal distribution"
  :pre (and (<= 0 u1 1) (<= 0 u2 1))
  (+ (* (* (/ 1 6) (pow (* -2 (log u1)) 0.5)) (cos (* (* 2 PI) u2))) 0.5))