Average Error: 1.7 → 0.6
Time: 32.5s
Precision: 64
Internal Precision: 576
\[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|\]
\[\begin{array}{l} \mathbf{if}\;\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right| \le 14884601944.499592:\\ \;\;\;\;\left|\frac{x + 4}{y} - x \cdot \frac{z}{y}\right|\\ \mathbf{else}:\\ \;\;\;\;\left|\frac{x}{y} \cdot \left(-z\right) + \left(\sqrt[3]{\frac{4}{y} + \frac{x}{y}} \cdot \sqrt[3]{\frac{4}{y} + \frac{x}{y}}\right) \cdot \sqrt[3]{\frac{4}{y} + \frac{x}{y}}\right|\\ \end{array}\]

Error

Bits error versus x

Bits error versus y

Bits error versus z

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Split input into 2 regimes
  2. if (fabs (- (/ (+ x 4) y) (* (/ x y) z))) < 14884601944.499592

    1. Initial program 3.8

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|\]
    2. Using strategy rm
    3. Applied div-inv3.9

      \[\leadsto \left|\frac{x + 4}{y} - \color{blue}{\left(x \cdot \frac{1}{y}\right)} \cdot z\right|\]
    4. Applied associate-*l*0.1

      \[\leadsto \left|\frac{x + 4}{y} - \color{blue}{x \cdot \left(\frac{1}{y} \cdot z\right)}\right|\]
    5. Applied simplify0.1

      \[\leadsto \left|\frac{x + 4}{y} - x \cdot \color{blue}{\frac{z}{y}}\right|\]

    if 14884601944.499592 < (fabs (- (/ (+ x 4) y) (* (/ x y) z)))

    1. Initial program 0.1

      \[\left|\frac{x + 4}{y} - \frac{x}{y} \cdot z\right|\]
    2. Taylor expanded around 0 5.1

      \[\leadsto \left|\color{blue}{\left(4 \cdot \frac{1}{y} + \frac{x}{y}\right) - \frac{z \cdot x}{y}}\right|\]
    3. Applied simplify0.1

      \[\leadsto \color{blue}{\left|\frac{x}{y} \cdot \left(-z\right) + \left(\frac{4}{y} + \frac{x}{y}\right)\right|}\]
    4. Using strategy rm
    5. Applied add-cube-cbrt0.9

      \[\leadsto \left|\frac{x}{y} \cdot \left(-z\right) + \color{blue}{\left(\sqrt[3]{\frac{4}{y} + \frac{x}{y}} \cdot \sqrt[3]{\frac{4}{y} + \frac{x}{y}}\right) \cdot \sqrt[3]{\frac{4}{y} + \frac{x}{y}}}\right|\]
  3. Recombined 2 regimes into one program.

Runtime

Time bar (total: 32.5s)Debug logProfile

herbie shell --seed 2018170 
(FPCore (x y z)
  :name "fabs fraction 1"
  (fabs (- (/ (+ x 4) y) (* (/ x y) z))))