\[\frac{e^{x}}{e^{x} - 1}\]
Test:
NMSE section 3.11
Bits:
128 bits
Bits error versus x
Time: 7.3 s
Input Error: 20.3
Output Error: 0.2
Log:
Profile: 🕒
\(\begin{cases} \frac{e^{x}}{(e^{x} - 1)^*} & \text{when } x \le 255.52292f0 \\ (\left((\frac{1}{2} * \left(\frac{1}{x}\right) + 1)_*\right) * \left(\frac{\frac{1}{(e^{\frac{1}{x}} - 1)^*}}{x}\right) + \left(\frac{1}{(e^{x} - 1)^*}\right))_* & \text{otherwise} \end{cases}\)

    if x < 255.52292f0

    1. Started with
      \[\frac{e^{x}}{e^{x} - 1}\]
      17.2
    2. Applied simplify to get
      \[\color{red}{\frac{e^{x}}{e^{x} - 1}} \leadsto \color{blue}{\frac{e^{x}}{(e^{x} - 1)^*}}\]
      0.2

    if 255.52292f0 < x

    1. Started with
      \[\frac{e^{x}}{e^{x} - 1}\]
      30.0
    2. Applied simplify to get
      \[\color{red}{\frac{e^{x}}{e^{x} - 1}} \leadsto \color{blue}{\frac{e^{x}}{(e^{x} - 1)^*}}\]
      30.0
    3. Applied taylor to get
      \[\frac{e^{x}}{(e^{x} - 1)^*} \leadsto \frac{1}{2} \cdot \frac{{x}^2}{(e^{x} - 1)^*} + \left(\frac{x}{(e^{x} - 1)^*} + \frac{1}{(e^{x} - 1)^*}\right)\]
      30.0
    4. Taylor expanded around 0 to get
      \[\color{red}{\frac{1}{2} \cdot \frac{{x}^2}{(e^{x} - 1)^*} + \left(\frac{x}{(e^{x} - 1)^*} + \frac{1}{(e^{x} - 1)^*}\right)} \leadsto \color{blue}{\frac{1}{2} \cdot \frac{{x}^2}{(e^{x} - 1)^*} + \left(\frac{x}{(e^{x} - 1)^*} + \frac{1}{(e^{x} - 1)^*}\right)}\]
      30.0
    5. Applied simplify to get
      \[\color{red}{\frac{1}{2} \cdot \frac{{x}^2}{(e^{x} - 1)^*} + \left(\frac{x}{(e^{x} - 1)^*} + \frac{1}{(e^{x} - 1)^*}\right)} \leadsto \color{blue}{\left(x \cdot \frac{1}{2} + 1\right) \cdot \frac{x}{(e^{x} - 1)^*} + \frac{1}{(e^{x} - 1)^*}}\]
      30.0
    6. Applied taylor to get
      \[\left(x \cdot \frac{1}{2} + 1\right) \cdot \frac{x}{(e^{x} - 1)^*} + \frac{1}{(e^{x} - 1)^*} \leadsto \left(x \cdot \frac{1}{2} + 1\right) \cdot \frac{x}{(e^{x} - 1)^*} + \frac{1}{(e^{\frac{1}{x}} - 1)^*}\]
      28.9
    7. Taylor expanded around inf to get
      \[\left(x \cdot \frac{1}{2} + 1\right) \cdot \frac{x}{(e^{x} - 1)^*} + \color{red}{\frac{1}{(e^{\frac{1}{x}} - 1)^*}} \leadsto \left(x \cdot \frac{1}{2} + 1\right) \cdot \frac{x}{(e^{x} - 1)^*} + \color{blue}{\frac{1}{(e^{\frac{1}{x}} - 1)^*}}\]
      28.9
    8. Applied simplify to get
      \[\color{red}{\left(x \cdot \frac{1}{2} + 1\right) \cdot \frac{x}{(e^{x} - 1)^*} + \frac{1}{(e^{\frac{1}{x}} - 1)^*}} \leadsto \color{blue}{(\left((\frac{1}{2} * x + 1)_*\right) * \left(\frac{x}{(e^{x} - 1)^*}\right) + \left(\frac{1}{(e^{\frac{1}{x}} - 1)^*}\right))_*}\]
      28.9
    9. Applied taylor to get
      \[(\left((\frac{1}{2} * x + 1)_*\right) * \left(\frac{x}{(e^{x} - 1)^*}\right) + \left(\frac{1}{(e^{\frac{1}{x}} - 1)^*}\right))_* \leadsto (\left((\frac{1}{2} * \left(\frac{1}{x}\right) + 1)_*\right) * \left(\frac{1}{(e^{\frac{1}{x}} - 1)^* \cdot x}\right) + \left(\frac{1}{(e^{x} - 1)^*}\right))_*\]
      0.2
    10. Taylor expanded around inf to get
      \[\color{red}{(\left((\frac{1}{2} * \left(\frac{1}{x}\right) + 1)_*\right) * \left(\frac{1}{(e^{\frac{1}{x}} - 1)^* \cdot x}\right) + \left(\frac{1}{(e^{x} - 1)^*}\right))_*} \leadsto \color{blue}{(\left((\frac{1}{2} * \left(\frac{1}{x}\right) + 1)_*\right) * \left(\frac{1}{(e^{\frac{1}{x}} - 1)^* \cdot x}\right) + \left(\frac{1}{(e^{x} - 1)^*}\right))_*}\]
      0.2
    11. Applied simplify to get
      \[(\left((\frac{1}{2} * \left(\frac{1}{x}\right) + 1)_*\right) * \left(\frac{1}{(e^{\frac{1}{x}} - 1)^* \cdot x}\right) + \left(\frac{1}{(e^{x} - 1)^*}\right))_* \leadsto (\left((\frac{1}{2} * \left(\frac{1}{x}\right) + 1)_*\right) * \left(\frac{\frac{1}{(e^{\frac{1}{x}} - 1)^*}}{x}\right) + \left(\frac{1}{(e^{x} - 1)^*}\right))_*\]
      0.2

    12. Applied final simplification

  1. Removed slow pow expressions

Original test:


(lambda ((x default))
  #:name "NMSE section 3.11"
  (/ (exp x) (- (exp x) 1))
  #:target
  (/ 1 (- 1 (exp (- x)))))