Average Error: 1.5 → 0.5
Time: 4.1m
Precision: 64
Internal Precision: 576
\[\left(\frac{1}{\sqrt{\pi}} \cdot e^{\left|x\right| \cdot \left|x\right|}\right) \cdot \left(\left(\left(\frac{1}{\left|x\right|} + \frac{1}{2} \cdot \left(\left(\frac{1}{\left|x\right|} \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right)\right) + \frac{3}{4} \cdot \left(\left(\left(\left(\frac{1}{\left|x\right|} \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right)\right) + \frac{15}{8} \cdot \left(\left(\left(\left(\left(\left(\frac{1}{\left|x\right|} \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right)\right)\]
\[\frac{{\left(\frac{1}{\left|x\right|}\right)}^{4} \cdot \frac{3}{4} + \left(1 + \frac{\frac{\frac{1}{2}}{\left|x\right|}}{\left|x\right|}\right)}{\frac{\left(\sqrt[3]{\sqrt{\pi} \cdot \left|x\right|} \cdot \sqrt[3]{\sqrt{\pi} \cdot \left|x\right|}\right) \cdot \sqrt[3]{\sqrt{\pi} \cdot \left|x\right|}}{e^{\left|x\right| \cdot \left|x\right|}}} + \left(\frac{\sqrt{\frac{1}{\pi}}}{{\left(\left|x\right|\right)}^{7}} \cdot \frac{15}{8}\right) \cdot e^{\left|x\right| \cdot \left|x\right|}\]

Error

Bits error versus x

Derivation

  1. Initial program 1.5

    \[\left(\frac{1}{\sqrt{\pi}} \cdot e^{\left|x\right| \cdot \left|x\right|}\right) \cdot \left(\left(\left(\frac{1}{\left|x\right|} + \frac{1}{2} \cdot \left(\left(\frac{1}{\left|x\right|} \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right)\right) + \frac{3}{4} \cdot \left(\left(\left(\left(\frac{1}{\left|x\right|} \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right)\right) + \frac{15}{8} \cdot \left(\left(\left(\left(\left(\left(\frac{1}{\left|x\right|} \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right) \cdot \frac{1}{\left|x\right|}\right)\right)\]
  2. Applied simplify1.4

    \[\leadsto \color{blue}{\left(\left({\left(\frac{1}{\left|x\right|}\right)}^{\left(3 + 1\right)} \cdot {\left(\frac{1}{\left|x\right|}\right)}^{3}\right) \cdot \left(\left(\frac{15}{8} \cdot \frac{1}{\sqrt{\pi}}\right) \cdot e^{\left|x\right| \cdot \left|x\right|}\right) + e^{\left|x\right| \cdot \left|x\right|} \cdot \left(\frac{1}{\sqrt{\pi}} \cdot \frac{1}{\left|x\right|}\right)\right) + \left(e^{\left|x\right| \cdot \left|x\right|} \cdot \left(\frac{1}{\sqrt{\pi}} \cdot \frac{1}{\left|x\right|}\right)\right) \cdot \left({\left(\frac{1}{\left|x\right|}\right)}^{\left(3 + 1\right)} \cdot \frac{3}{4} + \frac{\frac{1}{\left|x\right|}}{\frac{2}{\frac{1}{\left|x\right|}}}\right)}\]
  3. Taylor expanded around -inf 0.5

    \[\leadsto \left(\color{blue}{\frac{15}{8} \cdot \left(\sqrt{\frac{1}{\pi}} \cdot \frac{e^{{\left(\left|x\right|\right)}^{2}}}{{\left(\left|x\right|\right)}^{7}}\right)} + e^{\left|x\right| \cdot \left|x\right|} \cdot \left(\frac{1}{\sqrt{\pi}} \cdot \frac{1}{\left|x\right|}\right)\right) + \left(e^{\left|x\right| \cdot \left|x\right|} \cdot \left(\frac{1}{\sqrt{\pi}} \cdot \frac{1}{\left|x\right|}\right)\right) \cdot \left({\left(\frac{1}{\left|x\right|}\right)}^{\left(3 + 1\right)} \cdot \frac{3}{4} + \frac{\frac{1}{\left|x\right|}}{\frac{2}{\frac{1}{\left|x\right|}}}\right)\]
  4. Applied simplify0.5

    \[\leadsto \color{blue}{\left({\left(\frac{1}{\left|x\right|}\right)}^{\left(3 + 1\right)} \cdot \frac{3}{4} + \left(\frac{\frac{1}{\left|x\right|}}{2 \cdot \left|x\right|} + 1\right)\right) \cdot \left(\frac{\frac{1}{\sqrt{\pi}}}{\left|x\right|} \cdot e^{\left|x\right| \cdot \left|x\right|}\right) + \frac{\left(\frac{15}{8} \cdot \sqrt{\frac{1}{\pi}}\right) \cdot e^{\left|x\right| \cdot \left|x\right|}}{{\left(\left|x\right|\right)}^{7}}}\]
  5. Taylor expanded around 0 0.5

    \[\leadsto \left(\color{blue}{{\left(\frac{1}{\left|x\right|}\right)}^{4}} \cdot \frac{3}{4} + \left(\frac{\frac{1}{\left|x\right|}}{2 \cdot \left|x\right|} + 1\right)\right) \cdot \left(\frac{\frac{1}{\sqrt{\pi}}}{\left|x\right|} \cdot e^{\left|x\right| \cdot \left|x\right|}\right) + \frac{\left(\frac{15}{8} \cdot \sqrt{\frac{1}{\pi}}\right) \cdot e^{\left|x\right| \cdot \left|x\right|}}{{\left(\left|x\right|\right)}^{7}}\]
  6. Applied simplify0.5

    \[\leadsto \color{blue}{\frac{{\left(\frac{1}{\left|x\right|}\right)}^{4} \cdot \frac{3}{4} + \left(1 + \frac{\frac{\frac{1}{2}}{\left|x\right|}}{\left|x\right|}\right)}{\frac{\sqrt{\pi} \cdot \left|x\right|}{e^{\left|x\right| \cdot \left|x\right|}}} + \left(\frac{\sqrt{\frac{1}{\pi}}}{{\left(\left|x\right|\right)}^{7}} \cdot \frac{15}{8}\right) \cdot e^{\left|x\right| \cdot \left|x\right|}}\]
  7. Using strategy rm
  8. Applied add-cube-cbrt0.5

    \[\leadsto \frac{{\left(\frac{1}{\left|x\right|}\right)}^{4} \cdot \frac{3}{4} + \left(1 + \frac{\frac{\frac{1}{2}}{\left|x\right|}}{\left|x\right|}\right)}{\frac{\color{blue}{\left(\sqrt[3]{\sqrt{\pi} \cdot \left|x\right|} \cdot \sqrt[3]{\sqrt{\pi} \cdot \left|x\right|}\right) \cdot \sqrt[3]{\sqrt{\pi} \cdot \left|x\right|}}}{e^{\left|x\right| \cdot \left|x\right|}}} + \left(\frac{\sqrt{\frac{1}{\pi}}}{{\left(\left|x\right|\right)}^{7}} \cdot \frac{15}{8}\right) \cdot e^{\left|x\right| \cdot \left|x\right|}\]

Runtime

Time bar (total: 4.1m)Debug logProfile

herbie shell --seed '#(1071852389 864846987 1238109217 3425890003 4124793586 650694553)' 
(FPCore (x)
  :name "Jmat.Real.erfi, branch x greater than or equal to 5"
  (* (* (/ 1 (sqrt PI)) (exp (* (fabs x) (fabs x)))) (+ (+ (+ (/ 1 (fabs x)) (* (/ 1 2) (* (* (/ 1 (fabs x)) (/ 1 (fabs x))) (/ 1 (fabs x))))) (* (/ 3 4) (* (* (* (* (/ 1 (fabs x)) (/ 1 (fabs x))) (/ 1 (fabs x))) (/ 1 (fabs x))) (/ 1 (fabs x))))) (* (/ 15 8) (* (* (* (* (* (* (/ 1 (fabs x)) (/ 1 (fabs x))) (/ 1 (fabs x))) (/ 1 (fabs x))) (/ 1 (fabs x))) (/ 1 (fabs x))) (/ 1 (fabs x)))))))