Average Error: 24.0 → 12.7
Time: 42.2s
Precision: 64
Internal Precision: 1344
\[\frac{\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0} + 1.0}{2.0}\]
↓
\[\frac{(\left(\frac{\alpha + \beta}{(2 \cdot i + \alpha)_* + \left(\beta + 2.0\right)}\right) \cdot \left(\left(\beta - \alpha\right) \cdot \frac{1}{(2 \cdot i + \alpha)_* + \beta}\right) + 1.0)_*}{2.0}\]

Error

Bits error versus alpha

Bits error versus beta

Bits error versus i

Derivation

  1. Initial program 24.0

    \[\frac{\frac{\frac{\left(\alpha + \beta\right) \cdot \left(\beta - \alpha\right)}{\left(\alpha + \beta\right) + 2 \cdot i}}{\left(\left(\alpha + \beta\right) + 2 \cdot i\right) + 2.0} + 1.0}{2.0}\]

  2. Initial simplification12.8

    \[\leadsto \frac{(\left(\frac{\beta + \alpha}{(2 \cdot i + \alpha)_* + \left(\beta + 2.0\right)}\right) \cdot \left(\frac{\beta - \alpha}{(2 \cdot i + \alpha)_* + \beta}\right) + 1.0)_*}{2.0}\]
  3. Using strategy rm

  4. Applied div-inv12.7

    \[\leadsto \frac{(\left(\frac{\beta + \alpha}{(2 \cdot i + \alpha)_* + \left(\beta + 2.0\right)}\right) \cdot \color{blue}{\left(\left(\beta - \alpha\right) \cdot \frac{1}{(2 \cdot i + \alpha)_* + \beta}\right)} + 1.0)_*}{2.0}\]

  5. Final simplification12.7

    \[\leadsto \frac{(\left(\frac{\alpha + \beta}{(2 \cdot i + \alpha)_* + \left(\beta + 2.0\right)}\right) \cdot \left(\left(\beta - \alpha\right) \cdot \frac{1}{(2 \cdot i + \alpha)_* + \beta}\right) + 1.0)_*}{2.0}\]

Runtime

Time bar (total: 42.2s)Debug logProfile

herbie shell --seed 2018220 +o rules:numerics
(FPCore (alpha beta i)
  :name "Octave 3.8, jcobi/2"
  :pre (and (> alpha -1) (> beta -1) (> i 0))
  (/ (+ (/ (/ (* (+ alpha beta) (- beta alpha)) (+ (+ alpha beta) (* 2 i))) (+ (+ (+ alpha beta) (* 2 i)) 2.0)) 1.0) 2.0))