\[\frac{e^{x}}{e^{x} - 1}\]
Test:
NMSE section 3.11
Bits:
128 bits
Bits error versus x
Time: 7.5 s
Input Error: 20.7
Output Error: 0.0
Log:
Profile: 🕒
\(\begin{cases} e^{x} \cdot \frac{1}{\left(\frac{1}{2} + \frac{1}{6} \cdot x\right) \cdot {x}^2 + x} & \text{when } x \le 0.11032443f0 \\ \frac{1}{1 - e^{-x}} & \text{otherwise} \end{cases}\)

    if x < 0.11032443f0

    1. Started with
      \[\frac{e^{x}}{e^{x} - 1}\]
      18.3
    2. Applied taylor to get
      \[\frac{e^{x}}{e^{x} - 1} \leadsto \frac{e^{x}}{\frac{1}{2} \cdot {x}^2 + \left(\frac{1}{6} \cdot {x}^{3} + x\right)}\]
      5.2
    3. Taylor expanded around 0 to get
      \[\frac{e^{x}}{\color{red}{\frac{1}{2} \cdot {x}^2 + \left(\frac{1}{6} \cdot {x}^{3} + x\right)}} \leadsto \frac{e^{x}}{\color{blue}{\frac{1}{2} \cdot {x}^2 + \left(\frac{1}{6} \cdot {x}^{3} + x\right)}}\]
      5.2
    4. Using strategy rm
      5.2
    5. Applied div-inv to get
      \[\color{red}{\frac{e^{x}}{\frac{1}{2} \cdot {x}^2 + \left(\frac{1}{6} \cdot {x}^{3} + x\right)}} \leadsto \color{blue}{e^{x} \cdot \frac{1}{\frac{1}{2} \cdot {x}^2 + \left(\frac{1}{6} \cdot {x}^{3} + x\right)}}\]
      5.2
    6. Applied simplify to get
      \[e^{x} \cdot \color{red}{\frac{1}{\frac{1}{2} \cdot {x}^2 + \left(\frac{1}{6} \cdot {x}^{3} + x\right)}} \leadsto e^{x} \cdot \color{blue}{\frac{1}{x + \left(x \cdot x\right) \cdot \left(\frac{1}{6} \cdot x + \frac{1}{2}\right)}}\]
      0.1
    7. Applied simplify to get
      \[e^{x} \cdot \frac{1}{\color{red}{x + \left(x \cdot x\right) \cdot \left(\frac{1}{6} \cdot x + \frac{1}{2}\right)}} \leadsto e^{x} \cdot \frac{1}{\color{blue}{\left(\frac{1}{2} + \frac{1}{6} \cdot x\right) \cdot {x}^2 + x}}\]
      0.1

    if 0.11032443f0 < x

    1. Started with
      \[\frac{e^{x}}{e^{x} - 1}\]
      27.8
    2. Using strategy rm
      27.8
    3. Applied clear-num to get
      \[\color{red}{\frac{e^{x}}{e^{x} - 1}} \leadsto \color{blue}{\frac{1}{\frac{e^{x} - 1}{e^{x}}}}\]
      27.8
    4. Applied simplify to get
      \[\frac{1}{\color{red}{\frac{e^{x} - 1}{e^{x}}}} \leadsto \frac{1}{\color{blue}{1 - e^{-x}}}\]
      0.0

  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)))))