Average Error: 29.6 → 0.7
Time: 8.9s
Precision: binary64
Cost: 13632
\[\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}{2} \]
\[\begin{array}{l} t_0 := \frac{x + 1}{e^{x}}\\ \frac{t_0 + t_0}{2} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (/
  (-
   (* (+ 1.0 (/ 1.0 eps)) (exp (- (* (- 1.0 eps) x))))
   (* (- (/ 1.0 eps) 1.0) (exp (- (* (+ 1.0 eps) x)))))
  2.0))
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (/ (+ x 1.0) (exp x)))) (/ (+ t_0 t_0) 2.0)))
double code(double x, double eps) {
	return (((1.0 + (1.0 / eps)) * exp(-((1.0 - eps) * x))) - (((1.0 / eps) - 1.0) * exp(-((1.0 + eps) * x)))) / 2.0;
}
double code(double x, double eps) {
	double t_0 = (x + 1.0) / exp(x);
	return (t_0 + t_0) / 2.0;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = (((1.0d0 + (1.0d0 / eps)) * exp(-((1.0d0 - eps) * x))) - (((1.0d0 / eps) - 1.0d0) * exp(-((1.0d0 + eps) * x)))) / 2.0d0
end function
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    t_0 = (x + 1.0d0) / exp(x)
    code = (t_0 + t_0) / 2.0d0
end function
public static double code(double x, double eps) {
	return (((1.0 + (1.0 / eps)) * Math.exp(-((1.0 - eps) * x))) - (((1.0 / eps) - 1.0) * Math.exp(-((1.0 + eps) * x)))) / 2.0;
}
public static double code(double x, double eps) {
	double t_0 = (x + 1.0) / Math.exp(x);
	return (t_0 + t_0) / 2.0;
}
def code(x, eps):
	return (((1.0 + (1.0 / eps)) * math.exp(-((1.0 - eps) * x))) - (((1.0 / eps) - 1.0) * math.exp(-((1.0 + eps) * x)))) / 2.0
def code(x, eps):
	t_0 = (x + 1.0) / math.exp(x)
	return (t_0 + t_0) / 2.0
function code(x, eps)
	return Float64(Float64(Float64(Float64(1.0 + Float64(1.0 / eps)) * exp(Float64(-Float64(Float64(1.0 - eps) * x)))) - Float64(Float64(Float64(1.0 / eps) - 1.0) * exp(Float64(-Float64(Float64(1.0 + eps) * x))))) / 2.0)
end
function code(x, eps)
	t_0 = Float64(Float64(x + 1.0) / exp(x))
	return Float64(Float64(t_0 + t_0) / 2.0)
end
function tmp = code(x, eps)
	tmp = (((1.0 + (1.0 / eps)) * exp(-((1.0 - eps) * x))) - (((1.0 / eps) - 1.0) * exp(-((1.0 + eps) * x)))) / 2.0;
end
function tmp = code(x, eps)
	t_0 = (x + 1.0) / exp(x);
	tmp = (t_0 + t_0) / 2.0;
end
code[x_, eps_] := N[(N[(N[(N[(1.0 + N[(1.0 / eps), $MachinePrecision]), $MachinePrecision] * N[Exp[(-N[(N[(1.0 - eps), $MachinePrecision] * x), $MachinePrecision])], $MachinePrecision]), $MachinePrecision] - N[(N[(N[(1.0 / eps), $MachinePrecision] - 1.0), $MachinePrecision] * N[Exp[(-N[(N[(1.0 + eps), $MachinePrecision] * x), $MachinePrecision])], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision]
code[x_, eps_] := Block[{t$95$0 = N[(N[(x + 1.0), $MachinePrecision] / N[Exp[x], $MachinePrecision]), $MachinePrecision]}, N[(N[(t$95$0 + t$95$0), $MachinePrecision] / 2.0), $MachinePrecision]]
\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}{2}
\begin{array}{l}
t_0 := \frac{x + 1}{e^{x}}\\
\frac{t_0 + t_0}{2}
\end{array}

Error

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Initial program 29.6

    \[\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}{2} \]
  2. Simplified29.6

    \[\leadsto \color{blue}{\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{\left(1 - \varepsilon\right) \cdot \left(-x\right)} - \left(\frac{1}{\varepsilon} + -1\right) \cdot e^{\left(1 + \varepsilon\right) \cdot \left(-x\right)}}{2}} \]
    Proof
    (/.f64 (-.f64 (*.f64 (+.f64 1 (/.f64 1 eps)) (exp.f64 (*.f64 (-.f64 1 eps) (neg.f64 x)))) (*.f64 (+.f64 (/.f64 1 eps) -1) (exp.f64 (*.f64 (+.f64 1 eps) (neg.f64 x))))) 2): 0 points increase in error, 0 points decrease in error
    (/.f64 (-.f64 (*.f64 (+.f64 1 (/.f64 1 eps)) (exp.f64 (Rewrite<= distribute-rgt-neg-in_binary64 (neg.f64 (*.f64 (-.f64 1 eps) x))))) (*.f64 (+.f64 (/.f64 1 eps) -1) (exp.f64 (*.f64 (+.f64 1 eps) (neg.f64 x))))) 2): 0 points increase in error, 0 points decrease in error
    (/.f64 (-.f64 (*.f64 (+.f64 1 (/.f64 1 eps)) (exp.f64 (neg.f64 (*.f64 (-.f64 1 eps) x)))) (*.f64 (+.f64 (/.f64 1 eps) (Rewrite<= metadata-eval (neg.f64 1))) (exp.f64 (*.f64 (+.f64 1 eps) (neg.f64 x))))) 2): 0 points increase in error, 0 points decrease in error
    (/.f64 (-.f64 (*.f64 (+.f64 1 (/.f64 1 eps)) (exp.f64 (neg.f64 (*.f64 (-.f64 1 eps) x)))) (*.f64 (Rewrite<= sub-neg_binary64 (-.f64 (/.f64 1 eps) 1)) (exp.f64 (*.f64 (+.f64 1 eps) (neg.f64 x))))) 2): 0 points increase in error, 0 points decrease in error
    (/.f64 (-.f64 (*.f64 (+.f64 1 (/.f64 1 eps)) (exp.f64 (neg.f64 (*.f64 (-.f64 1 eps) x)))) (*.f64 (-.f64 (/.f64 1 eps) 1) (exp.f64 (Rewrite<= distribute-rgt-neg-in_binary64 (neg.f64 (*.f64 (+.f64 1 eps) x)))))) 2): 0 points increase in error, 0 points decrease in error
  3. Taylor expanded in eps around 0 0.7

    \[\leadsto \frac{\color{blue}{\left(e^{-1 \cdot x} \cdot x + e^{-1 \cdot x}\right) - \left(-1 \cdot \left(e^{-1 \cdot x} \cdot x\right) + -1 \cdot e^{-1 \cdot x}\right)}}{2} \]
  4. Simplified0.7

    \[\leadsto \frac{\color{blue}{\left(x + 1\right) \cdot e^{-x} - \left(-\left(x + 1\right) \cdot e^{-x}\right)}}{2} \]
    Proof
    (-.f64 (*.f64 (+.f64 x 1) (exp.f64 (neg.f64 x))) (neg.f64 (*.f64 (+.f64 x 1) (exp.f64 (neg.f64 x))))): 0 points increase in error, 0 points decrease in error
    (-.f64 (*.f64 (+.f64 x 1) (exp.f64 (Rewrite<= mul-1-neg_binary64 (*.f64 -1 x)))) (neg.f64 (*.f64 (+.f64 x 1) (exp.f64 (neg.f64 x))))): 0 points increase in error, 0 points decrease in error
    (-.f64 (Rewrite<= distribute-lft1-in_binary64 (+.f64 (*.f64 x (exp.f64 (*.f64 -1 x))) (exp.f64 (*.f64 -1 x)))) (neg.f64 (*.f64 (+.f64 x 1) (exp.f64 (neg.f64 x))))): 1 points increase in error, 1 points decrease in error
    (-.f64 (+.f64 (Rewrite<= *-commutative_binary64 (*.f64 (exp.f64 (*.f64 -1 x)) x)) (exp.f64 (*.f64 -1 x))) (neg.f64 (*.f64 (+.f64 x 1) (exp.f64 (neg.f64 x))))): 0 points increase in error, 0 points decrease in error
    (-.f64 (+.f64 (*.f64 (exp.f64 (*.f64 -1 x)) x) (exp.f64 (*.f64 -1 x))) (neg.f64 (*.f64 (+.f64 x 1) (exp.f64 (Rewrite<= mul-1-neg_binary64 (*.f64 -1 x)))))): 0 points increase in error, 0 points decrease in error
    (-.f64 (+.f64 (*.f64 (exp.f64 (*.f64 -1 x)) x) (exp.f64 (*.f64 -1 x))) (neg.f64 (Rewrite<= distribute-lft1-in_binary64 (+.f64 (*.f64 x (exp.f64 (*.f64 -1 x))) (exp.f64 (*.f64 -1 x)))))): 0 points increase in error, 1 points decrease in error
    (-.f64 (+.f64 (*.f64 (exp.f64 (*.f64 -1 x)) x) (exp.f64 (*.f64 -1 x))) (neg.f64 (+.f64 (Rewrite<= *-commutative_binary64 (*.f64 (exp.f64 (*.f64 -1 x)) x)) (exp.f64 (*.f64 -1 x))))): 0 points increase in error, 0 points decrease in error
    (-.f64 (+.f64 (*.f64 (exp.f64 (*.f64 -1 x)) x) (exp.f64 (*.f64 -1 x))) (Rewrite<= mul-1-neg_binary64 (*.f64 -1 (+.f64 (*.f64 (exp.f64 (*.f64 -1 x)) x) (exp.f64 (*.f64 -1 x)))))): 0 points increase in error, 0 points decrease in error
    (-.f64 (+.f64 (*.f64 (exp.f64 (*.f64 -1 x)) x) (exp.f64 (*.f64 -1 x))) (Rewrite<= distribute-lft-out_binary64 (+.f64 (*.f64 -1 (*.f64 (exp.f64 (*.f64 -1 x)) x)) (*.f64 -1 (exp.f64 (*.f64 -1 x)))))): 0 points increase in error, 0 points decrease in error
  5. Applied egg-rr0.7

    \[\leadsto \frac{\color{blue}{\frac{x + 1}{e^{x}}} - \left(-\left(x + 1\right) \cdot e^{-x}\right)}{2} \]
  6. Applied egg-rr0.7

    \[\leadsto \frac{\frac{x + 1}{e^{x}} - \left(-\color{blue}{\frac{x + 1}{e^{x}}}\right)}{2} \]
  7. Final simplification0.7

    \[\leadsto \frac{\frac{x + 1}{e^{x}} + \frac{x + 1}{e^{x}}}{2} \]

Alternatives

Alternative 1
Error1.1
Cost13636
\[\begin{array}{l} \mathbf{if}\;x \leq 1.1:\\ \;\;\;\;\frac{\left(1 + -0.5 \cdot \left(x \cdot x\right)\right) + \left(x + 1\right) \cdot e^{-x}}{2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{x + 1}{e^{x}} + \frac{x}{e^{x}}}{2}\\ \end{array} \]
Alternative 2
Error1.1
Cost7556
\[\begin{array}{l} \mathbf{if}\;x \leq 1.75:\\ \;\;\;\;\frac{\left(1 + -0.5 \cdot \left(x \cdot x\right)\right) + \left(x + 1\right) \cdot e^{-x}}{2}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
Alternative 3
Error1.1
Cost7492
\[\begin{array}{l} \mathbf{if}\;x \leq 1.75:\\ \;\;\;\;\frac{\frac{x + 1}{e^{x}} + \left(1 + -0.5 \cdot \left(x \cdot x\right)\right)}{2}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
Alternative 4
Error1.2
Cost7108
\[\begin{array}{l} \mathbf{if}\;x \leq 360:\\ \;\;\;\;\frac{1 + \frac{x + 1}{e^{x}}}{2}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
Alternative 5
Error1.2
Cost836
\[\begin{array}{l} \mathbf{if}\;x \leq 2:\\ \;\;\;\;\frac{1 + \left(1 + -0.5 \cdot \left(x \cdot x\right)\right)}{2}\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
Alternative 6
Error1.2
Cost196
\[\begin{array}{l} \mathbf{if}\;x \leq 360:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;0\\ \end{array} \]
Alternative 7
Error46.5
Cost64
\[0 \]

Error

Reproduce

herbie shell --seed 2022329 
(FPCore (x eps)
  :name "NMSE Section 6.1 mentioned, A"
  :precision binary64
  (/ (- (* (+ 1.0 (/ 1.0 eps)) (exp (- (* (- 1.0 eps) x)))) (* (- (/ 1.0 eps) 1.0) (exp (- (* (+ 1.0 eps) x))))) 2.0))