Falkner and Boettcher, Equation (20:1,3)

Percentage Accurate: 99.3% → 99.4%
Time: 10.5s
Alternatives: 8
Speedup: 1.0×

Specification

?
\[\begin{array}{l} \\ \frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)} \end{array} \]
(FPCore (v t)
 :precision binary64
 (/
  (- 1.0 (* 5.0 (* v v)))
  (* (* (* PI t) (sqrt (* 2.0 (- 1.0 (* 3.0 (* v v)))))) (- 1.0 (* v v)))))
double code(double v, double t) {
	return (1.0 - (5.0 * (v * v))) / (((((double) M_PI) * t) * sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)));
}
public static double code(double v, double t) {
	return (1.0 - (5.0 * (v * v))) / (((Math.PI * t) * Math.sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)));
}
def code(v, t):
	return (1.0 - (5.0 * (v * v))) / (((math.pi * t) * math.sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)))
function code(v, t)
	return Float64(Float64(1.0 - Float64(5.0 * Float64(v * v))) / Float64(Float64(Float64(pi * t) * sqrt(Float64(2.0 * Float64(1.0 - Float64(3.0 * Float64(v * v)))))) * Float64(1.0 - Float64(v * v))))
end
function tmp = code(v, t)
	tmp = (1.0 - (5.0 * (v * v))) / (((pi * t) * sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)));
end
code[v_, t_] := N[(N[(1.0 - N[(5.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(Pi * t), $MachinePrecision] * N[Sqrt[N[(2.0 * N[(1.0 - N[(3.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 8 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 99.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)} \end{array} \]
(FPCore (v t)
 :precision binary64
 (/
  (- 1.0 (* 5.0 (* v v)))
  (* (* (* PI t) (sqrt (* 2.0 (- 1.0 (* 3.0 (* v v)))))) (- 1.0 (* v v)))))
double code(double v, double t) {
	return (1.0 - (5.0 * (v * v))) / (((((double) M_PI) * t) * sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)));
}
public static double code(double v, double t) {
	return (1.0 - (5.0 * (v * v))) / (((Math.PI * t) * Math.sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)));
}
def code(v, t):
	return (1.0 - (5.0 * (v * v))) / (((math.pi * t) * math.sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)))
function code(v, t)
	return Float64(Float64(1.0 - Float64(5.0 * Float64(v * v))) / Float64(Float64(Float64(pi * t) * sqrt(Float64(2.0 * Float64(1.0 - Float64(3.0 * Float64(v * v)))))) * Float64(1.0 - Float64(v * v))))
end
function tmp = code(v, t)
	tmp = (1.0 - (5.0 * (v * v))) / (((pi * t) * sqrt((2.0 * (1.0 - (3.0 * (v * v)))))) * (1.0 - (v * v)));
end
code[v_, t_] := N[(N[(1.0 - N[(5.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(N[(Pi * t), $MachinePrecision] * N[Sqrt[N[(2.0 * N[(1.0 - N[(3.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)}
\end{array}

Alternative 1: 99.4% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(t \cdot \left(\sqrt{2 \cdot \left(1 - 3 \cdot {v}^{2}\right)} \cdot \pi\right)\right) \cdot \left(1 - v \cdot v\right)} \end{array} \]
(FPCore (v t)
 :precision binary64
 (/
  (+ 1.0 (* -5.0 (* v v)))
  (* (* t (* (sqrt (* 2.0 (- 1.0 (* 3.0 (pow v 2.0))))) PI)) (- 1.0 (* v v)))))
double code(double v, double t) {
	return (1.0 + (-5.0 * (v * v))) / ((t * (sqrt((2.0 * (1.0 - (3.0 * pow(v, 2.0))))) * ((double) M_PI))) * (1.0 - (v * v)));
}
public static double code(double v, double t) {
	return (1.0 + (-5.0 * (v * v))) / ((t * (Math.sqrt((2.0 * (1.0 - (3.0 * Math.pow(v, 2.0))))) * Math.PI)) * (1.0 - (v * v)));
}
def code(v, t):
	return (1.0 + (-5.0 * (v * v))) / ((t * (math.sqrt((2.0 * (1.0 - (3.0 * math.pow(v, 2.0))))) * math.pi)) * (1.0 - (v * v)))
function code(v, t)
	return Float64(Float64(1.0 + Float64(-5.0 * Float64(v * v))) / Float64(Float64(t * Float64(sqrt(Float64(2.0 * Float64(1.0 - Float64(3.0 * (v ^ 2.0))))) * pi)) * Float64(1.0 - Float64(v * v))))
end
function tmp = code(v, t)
	tmp = (1.0 + (-5.0 * (v * v))) / ((t * (sqrt((2.0 * (1.0 - (3.0 * (v ^ 2.0))))) * pi)) * (1.0 - (v * v)));
end
code[v_, t_] := N[(N[(1.0 + N[(-5.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(t * N[(N[Sqrt[N[(2.0 * N[(1.0 - N[(3.0 * N[Power[v, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * Pi), $MachinePrecision]), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(t \cdot \left(\sqrt{2 \cdot \left(1 - 3 \cdot {v}^{2}\right)} \cdot \pi\right)\right) \cdot \left(1 - v \cdot v\right)}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)} \]
  2. Simplified99.4%

    \[\leadsto \color{blue}{\frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(\pi \cdot \left(t \cdot \sqrt{2 \cdot \left(1 - \left(3 \cdot v\right) \cdot v\right)}\right)\right) \cdot \left(1 - v \cdot v\right)}} \]
  3. Step-by-step derivation
    1. expm1-log1p-u67.5%

      \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\pi \cdot \left(t \cdot \sqrt{2 \cdot \left(1 - \left(3 \cdot v\right) \cdot v\right)}\right)\right)\right)} \cdot \left(1 - v \cdot v\right)} \]
    2. expm1-udef21.6%

      \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\color{blue}{\left(e^{\mathsf{log1p}\left(\pi \cdot \left(t \cdot \sqrt{2 \cdot \left(1 - \left(3 \cdot v\right) \cdot v\right)}\right)\right)} - 1\right)} \cdot \left(1 - v \cdot v\right)} \]
    3. *-commutative21.6%

      \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(e^{\mathsf{log1p}\left(\color{blue}{\left(t \cdot \sqrt{2 \cdot \left(1 - \left(3 \cdot v\right) \cdot v\right)}\right) \cdot \pi}\right)} - 1\right) \cdot \left(1 - v \cdot v\right)} \]
    4. associate-*l*21.6%

      \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(e^{\mathsf{log1p}\left(\left(t \cdot \sqrt{2 \cdot \left(1 - \color{blue}{3 \cdot \left(v \cdot v\right)}\right)}\right) \cdot \pi\right)} - 1\right) \cdot \left(1 - v \cdot v\right)} \]
    5. pow221.6%

      \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(e^{\mathsf{log1p}\left(\left(t \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \color{blue}{{v}^{2}}\right)}\right) \cdot \pi\right)} - 1\right) \cdot \left(1 - v \cdot v\right)} \]
  4. Applied egg-rr21.6%

    \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\color{blue}{\left(e^{\mathsf{log1p}\left(\left(t \cdot \sqrt{2 \cdot \left(1 - 3 \cdot {v}^{2}\right)}\right) \cdot \pi\right)} - 1\right)} \cdot \left(1 - v \cdot v\right)} \]
  5. Step-by-step derivation
    1. expm1-def67.5%

      \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\left(t \cdot \sqrt{2 \cdot \left(1 - 3 \cdot {v}^{2}\right)}\right) \cdot \pi\right)\right)} \cdot \left(1 - v \cdot v\right)} \]
    2. expm1-log1p99.4%

      \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\color{blue}{\left(\left(t \cdot \sqrt{2 \cdot \left(1 - 3 \cdot {v}^{2}\right)}\right) \cdot \pi\right)} \cdot \left(1 - v \cdot v\right)} \]
    3. associate-*l*99.5%

      \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\color{blue}{\left(t \cdot \left(\sqrt{2 \cdot \left(1 - 3 \cdot {v}^{2}\right)} \cdot \pi\right)\right)} \cdot \left(1 - v \cdot v\right)} \]
  6. Simplified99.5%

    \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\color{blue}{\left(t \cdot \left(\sqrt{2 \cdot \left(1 - 3 \cdot {v}^{2}\right)} \cdot \pi\right)\right)} \cdot \left(1 - v \cdot v\right)} \]
  7. Final simplification99.5%

    \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(t \cdot \left(\sqrt{2 \cdot \left(1 - 3 \cdot {v}^{2}\right)} \cdot \pi\right)\right) \cdot \left(1 - v \cdot v\right)} \]

Alternative 2: 99.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(1 - v \cdot v\right) \cdot \left(\pi \cdot \left(t \cdot \sqrt{2 \cdot \left(1 - v \cdot \left(v \cdot 3\right)\right)}\right)\right)} \end{array} \]
(FPCore (v t)
 :precision binary64
 (/
  (+ 1.0 (* -5.0 (* v v)))
  (* (- 1.0 (* v v)) (* PI (* t (sqrt (* 2.0 (- 1.0 (* v (* v 3.0))))))))))
double code(double v, double t) {
	return (1.0 + (-5.0 * (v * v))) / ((1.0 - (v * v)) * (((double) M_PI) * (t * sqrt((2.0 * (1.0 - (v * (v * 3.0))))))));
}
public static double code(double v, double t) {
	return (1.0 + (-5.0 * (v * v))) / ((1.0 - (v * v)) * (Math.PI * (t * Math.sqrt((2.0 * (1.0 - (v * (v * 3.0))))))));
}
def code(v, t):
	return (1.0 + (-5.0 * (v * v))) / ((1.0 - (v * v)) * (math.pi * (t * math.sqrt((2.0 * (1.0 - (v * (v * 3.0))))))))
function code(v, t)
	return Float64(Float64(1.0 + Float64(-5.0 * Float64(v * v))) / Float64(Float64(1.0 - Float64(v * v)) * Float64(pi * Float64(t * sqrt(Float64(2.0 * Float64(1.0 - Float64(v * Float64(v * 3.0)))))))))
end
function tmp = code(v, t)
	tmp = (1.0 + (-5.0 * (v * v))) / ((1.0 - (v * v)) * (pi * (t * sqrt((2.0 * (1.0 - (v * (v * 3.0))))))));
end
code[v_, t_] := N[(N[(1.0 + N[(-5.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision] * N[(Pi * N[(t * N[Sqrt[N[(2.0 * N[(1.0 - N[(v * N[(v * 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(1 - v \cdot v\right) \cdot \left(\pi \cdot \left(t \cdot \sqrt{2 \cdot \left(1 - v \cdot \left(v \cdot 3\right)\right)}\right)\right)}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)} \]
  2. Simplified99.4%

    \[\leadsto \color{blue}{\frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(\pi \cdot \left(t \cdot \sqrt{2 \cdot \left(1 - \left(3 \cdot v\right) \cdot v\right)}\right)\right) \cdot \left(1 - v \cdot v\right)}} \]
  3. Final simplification99.4%

    \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(1 - v \cdot v\right) \cdot \left(\pi \cdot \left(t \cdot \sqrt{2 \cdot \left(1 - v \cdot \left(v \cdot 3\right)\right)}\right)\right)} \]

Alternative 3: 99.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1 - \left(v \cdot v\right) \cdot 5}{\left(1 - v \cdot v\right) \cdot \left(\sqrt{2 \cdot \left(1 - \left(v \cdot v\right) \cdot 3\right)} \cdot \left(t \cdot \pi\right)\right)} \end{array} \]
(FPCore (v t)
 :precision binary64
 (/
  (- 1.0 (* (* v v) 5.0))
  (* (- 1.0 (* v v)) (* (sqrt (* 2.0 (- 1.0 (* (* v v) 3.0)))) (* t PI)))))
double code(double v, double t) {
	return (1.0 - ((v * v) * 5.0)) / ((1.0 - (v * v)) * (sqrt((2.0 * (1.0 - ((v * v) * 3.0)))) * (t * ((double) M_PI))));
}
public static double code(double v, double t) {
	return (1.0 - ((v * v) * 5.0)) / ((1.0 - (v * v)) * (Math.sqrt((2.0 * (1.0 - ((v * v) * 3.0)))) * (t * Math.PI)));
}
def code(v, t):
	return (1.0 - ((v * v) * 5.0)) / ((1.0 - (v * v)) * (math.sqrt((2.0 * (1.0 - ((v * v) * 3.0)))) * (t * math.pi)))
function code(v, t)
	return Float64(Float64(1.0 - Float64(Float64(v * v) * 5.0)) / Float64(Float64(1.0 - Float64(v * v)) * Float64(sqrt(Float64(2.0 * Float64(1.0 - Float64(Float64(v * v) * 3.0)))) * Float64(t * pi))))
end
function tmp = code(v, t)
	tmp = (1.0 - ((v * v) * 5.0)) / ((1.0 - (v * v)) * (sqrt((2.0 * (1.0 - ((v * v) * 3.0)))) * (t * pi)));
end
code[v_, t_] := N[(N[(1.0 - N[(N[(v * v), $MachinePrecision] * 5.0), $MachinePrecision]), $MachinePrecision] / N[(N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision] * N[(N[Sqrt[N[(2.0 * N[(1.0 - N[(N[(v * v), $MachinePrecision] * 3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(t * Pi), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1 - \left(v \cdot v\right) \cdot 5}{\left(1 - v \cdot v\right) \cdot \left(\sqrt{2 \cdot \left(1 - \left(v \cdot v\right) \cdot 3\right)} \cdot \left(t \cdot \pi\right)\right)}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)} \]
  2. Final simplification99.4%

    \[\leadsto \frac{1 - \left(v \cdot v\right) \cdot 5}{\left(1 - v \cdot v\right) \cdot \left(\sqrt{2 \cdot \left(1 - \left(v \cdot v\right) \cdot 3\right)} \cdot \left(t \cdot \pi\right)\right)} \]

Alternative 4: 98.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(1 - v \cdot v\right) \cdot \left(t \cdot \left(\pi \cdot \sqrt{2}\right)\right)} \end{array} \]
(FPCore (v t)
 :precision binary64
 (/ (+ 1.0 (* -5.0 (* v v))) (* (- 1.0 (* v v)) (* t (* PI (sqrt 2.0))))))
double code(double v, double t) {
	return (1.0 + (-5.0 * (v * v))) / ((1.0 - (v * v)) * (t * (((double) M_PI) * sqrt(2.0))));
}
public static double code(double v, double t) {
	return (1.0 + (-5.0 * (v * v))) / ((1.0 - (v * v)) * (t * (Math.PI * Math.sqrt(2.0))));
}
def code(v, t):
	return (1.0 + (-5.0 * (v * v))) / ((1.0 - (v * v)) * (t * (math.pi * math.sqrt(2.0))))
function code(v, t)
	return Float64(Float64(1.0 + Float64(-5.0 * Float64(v * v))) / Float64(Float64(1.0 - Float64(v * v)) * Float64(t * Float64(pi * sqrt(2.0)))))
end
function tmp = code(v, t)
	tmp = (1.0 + (-5.0 * (v * v))) / ((1.0 - (v * v)) * (t * (pi * sqrt(2.0))));
end
code[v_, t_] := N[(N[(1.0 + N[(-5.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision] * N[(t * N[(Pi * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(1 - v \cdot v\right) \cdot \left(t \cdot \left(\pi \cdot \sqrt{2}\right)\right)}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)} \]
  2. Simplified99.4%

    \[\leadsto \color{blue}{\frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(\pi \cdot \left(t \cdot \sqrt{2 \cdot \left(1 - \left(3 \cdot v\right) \cdot v\right)}\right)\right) \cdot \left(1 - v \cdot v\right)}} \]
  3. Taylor expanded in v around 0 97.7%

    \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\color{blue}{\left(t \cdot \left(\pi \cdot \sqrt{2}\right)\right)} \cdot \left(1 - v \cdot v\right)} \]
  4. Step-by-step derivation
    1. *-commutative97.7%

      \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(t \cdot \color{blue}{\left(\sqrt{2} \cdot \pi\right)}\right) \cdot \left(1 - v \cdot v\right)} \]
  5. Simplified97.7%

    \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\color{blue}{\left(t \cdot \left(\sqrt{2} \cdot \pi\right)\right)} \cdot \left(1 - v \cdot v\right)} \]
  6. Final simplification97.7%

    \[\leadsto \frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(1 - v \cdot v\right) \cdot \left(t \cdot \left(\pi \cdot \sqrt{2}\right)\right)} \]

Alternative 5: 98.5% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \frac{1}{t} \cdot \frac{\frac{1}{\pi}}{\sqrt{2}} \end{array} \]
(FPCore (v t) :precision binary64 (* (/ 1.0 t) (/ (/ 1.0 PI) (sqrt 2.0))))
double code(double v, double t) {
	return (1.0 / t) * ((1.0 / ((double) M_PI)) / sqrt(2.0));
}
public static double code(double v, double t) {
	return (1.0 / t) * ((1.0 / Math.PI) / Math.sqrt(2.0));
}
def code(v, t):
	return (1.0 / t) * ((1.0 / math.pi) / math.sqrt(2.0))
function code(v, t)
	return Float64(Float64(1.0 / t) * Float64(Float64(1.0 / pi) / sqrt(2.0)))
end
function tmp = code(v, t)
	tmp = (1.0 / t) * ((1.0 / pi) / sqrt(2.0));
end
code[v_, t_] := N[(N[(1.0 / t), $MachinePrecision] * N[(N[(1.0 / Pi), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{t} \cdot \frac{\frac{1}{\pi}}{\sqrt{2}}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)} \]
  2. Simplified99.4%

    \[\leadsto \color{blue}{\frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(\pi \cdot \left(t \cdot \sqrt{2 \cdot \left(1 - \left(3 \cdot v\right) \cdot v\right)}\right)\right) \cdot \left(1 - v \cdot v\right)}} \]
  3. Taylor expanded in v around 0 97.7%

    \[\leadsto \color{blue}{\frac{1}{t \cdot \left(\pi \cdot \sqrt{2}\right)}} \]
  4. Step-by-step derivation
    1. associate-*r*97.5%

      \[\leadsto \frac{1}{\color{blue}{\left(t \cdot \pi\right) \cdot \sqrt{2}}} \]
  5. Simplified97.5%

    \[\leadsto \color{blue}{\frac{1}{\left(t \cdot \pi\right) \cdot \sqrt{2}}} \]
  6. Taylor expanded in t around 0 97.7%

    \[\leadsto \color{blue}{\frac{1}{t \cdot \left(\pi \cdot \sqrt{2}\right)}} \]
  7. Step-by-step derivation
    1. associate-*r*97.5%

      \[\leadsto \frac{1}{\color{blue}{\left(t \cdot \pi\right) \cdot \sqrt{2}}} \]
    2. associate-/r*97.6%

      \[\leadsto \color{blue}{\frac{\frac{1}{t \cdot \pi}}{\sqrt{2}}} \]
    3. associate-/r*97.6%

      \[\leadsto \frac{\color{blue}{\frac{\frac{1}{t}}{\pi}}}{\sqrt{2}} \]
  8. Simplified97.6%

    \[\leadsto \color{blue}{\frac{\frac{\frac{1}{t}}{\pi}}{\sqrt{2}}} \]
  9. Step-by-step derivation
    1. div-inv97.6%

      \[\leadsto \frac{\color{blue}{\frac{1}{t} \cdot \frac{1}{\pi}}}{\sqrt{2}} \]
    2. *-un-lft-identity97.6%

      \[\leadsto \frac{\frac{1}{t} \cdot \frac{1}{\pi}}{\color{blue}{1 \cdot \sqrt{2}}} \]
    3. times-frac97.7%

      \[\leadsto \color{blue}{\frac{\frac{1}{t}}{1} \cdot \frac{\frac{1}{\pi}}{\sqrt{2}}} \]
  10. Applied egg-rr97.7%

    \[\leadsto \color{blue}{\frac{\frac{1}{t}}{1} \cdot \frac{\frac{1}{\pi}}{\sqrt{2}}} \]
  11. Final simplification97.7%

    \[\leadsto \frac{1}{t} \cdot \frac{\frac{1}{\pi}}{\sqrt{2}} \]

Alternative 6: 98.3% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \frac{1}{t \cdot \left(\pi \cdot \sqrt{2}\right)} \end{array} \]
(FPCore (v t) :precision binary64 (/ 1.0 (* t (* PI (sqrt 2.0)))))
double code(double v, double t) {
	return 1.0 / (t * (((double) M_PI) * sqrt(2.0)));
}
public static double code(double v, double t) {
	return 1.0 / (t * (Math.PI * Math.sqrt(2.0)));
}
def code(v, t):
	return 1.0 / (t * (math.pi * math.sqrt(2.0)))
function code(v, t)
	return Float64(1.0 / Float64(t * Float64(pi * sqrt(2.0))))
end
function tmp = code(v, t)
	tmp = 1.0 / (t * (pi * sqrt(2.0)));
end
code[v_, t_] := N[(1.0 / N[(t * N[(Pi * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{t \cdot \left(\pi \cdot \sqrt{2}\right)}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)} \]
  2. Simplified99.4%

    \[\leadsto \color{blue}{\frac{1 + -5 \cdot \left(v \cdot v\right)}{\left(\pi \cdot \left(t \cdot \sqrt{2 \cdot \left(1 - \left(3 \cdot v\right) \cdot v\right)}\right)\right) \cdot \left(1 - v \cdot v\right)}} \]
  3. Taylor expanded in v around 0 97.7%

    \[\leadsto \color{blue}{\frac{1}{t \cdot \left(\pi \cdot \sqrt{2}\right)}} \]
  4. Step-by-step derivation
    1. *-commutative97.7%

      \[\leadsto \frac{1}{t \cdot \color{blue}{\left(\sqrt{2} \cdot \pi\right)}} \]
  5. Simplified97.7%

    \[\leadsto \color{blue}{\frac{1}{t \cdot \left(\sqrt{2} \cdot \pi\right)}} \]
  6. Final simplification97.7%

    \[\leadsto \frac{1}{t \cdot \left(\pi \cdot \sqrt{2}\right)} \]

Alternative 7: 97.8% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \frac{\sqrt{0.5}}{t \cdot \pi} \end{array} \]
(FPCore (v t) :precision binary64 (/ (sqrt 0.5) (* t PI)))
double code(double v, double t) {
	return sqrt(0.5) / (t * ((double) M_PI));
}
public static double code(double v, double t) {
	return Math.sqrt(0.5) / (t * Math.PI);
}
def code(v, t):
	return math.sqrt(0.5) / (t * math.pi)
function code(v, t)
	return Float64(sqrt(0.5) / Float64(t * pi))
end
function tmp = code(v, t)
	tmp = sqrt(0.5) / (t * pi);
end
code[v_, t_] := N[(N[Sqrt[0.5], $MachinePrecision] / N[(t * Pi), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\sqrt{0.5}}{t \cdot \pi}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)} \]
  2. Step-by-step derivation
    1. associate-*l*99.4%

      \[\leadsto \frac{1 - 5 \cdot \left(v \cdot v\right)}{\color{blue}{\left(\pi \cdot t\right) \cdot \left(\sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)} \cdot \left(1 - v \cdot v\right)\right)}} \]
    2. associate-*r*99.4%

      \[\leadsto \frac{1 - \color{blue}{\left(5 \cdot v\right) \cdot v}}{\left(\pi \cdot t\right) \cdot \left(\sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)} \cdot \left(1 - v \cdot v\right)\right)} \]
    3. *-commutative99.4%

      \[\leadsto \frac{1 - \color{blue}{v \cdot \left(5 \cdot v\right)}}{\left(\pi \cdot t\right) \cdot \left(\sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)} \cdot \left(1 - v \cdot v\right)\right)} \]
    4. *-commutative99.4%

      \[\leadsto \frac{1 - v \cdot \left(5 \cdot v\right)}{\color{blue}{\left(\sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)} \cdot \left(1 - v \cdot v\right)\right) \cdot \left(\pi \cdot t\right)}} \]
    5. associate-*l*99.4%

      \[\leadsto \frac{1 - v \cdot \left(5 \cdot v\right)}{\color{blue}{\sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)} \cdot \left(\left(1 - v \cdot v\right) \cdot \left(\pi \cdot t\right)\right)}} \]
  3. Simplified99.4%

    \[\leadsto \color{blue}{\frac{1 - v \cdot \left(5 \cdot v\right)}{\sqrt{2 + 2 \cdot \left(\left(-3 \cdot v\right) \cdot v\right)} \cdot \left(\left(\pi \cdot t\right) \cdot \left(1 - v \cdot v\right)\right)}} \]
  4. Taylor expanded in v around 0 97.1%

    \[\leadsto \color{blue}{\frac{\sqrt{0.5}}{t \cdot \pi}} \]
  5. Final simplification97.1%

    \[\leadsto \frac{\sqrt{0.5}}{t \cdot \pi} \]

Alternative 8: 97.8% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \frac{\frac{\sqrt{0.5}}{t}}{\pi} \end{array} \]
(FPCore (v t) :precision binary64 (/ (/ (sqrt 0.5) t) PI))
double code(double v, double t) {
	return (sqrt(0.5) / t) / ((double) M_PI);
}
public static double code(double v, double t) {
	return (Math.sqrt(0.5) / t) / Math.PI;
}
def code(v, t):
	return (math.sqrt(0.5) / t) / math.pi
function code(v, t)
	return Float64(Float64(sqrt(0.5) / t) / pi)
end
function tmp = code(v, t)
	tmp = (sqrt(0.5) / t) / pi;
end
code[v_, t_] := N[(N[(N[Sqrt[0.5], $MachinePrecision] / t), $MachinePrecision] / Pi), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{\sqrt{0.5}}{t}}{\pi}
\end{array}
Derivation
  1. Initial program 99.4%

    \[\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\pi \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)} \]
  2. Step-by-step derivation
    1. associate-*l*99.4%

      \[\leadsto \frac{1 - 5 \cdot \left(v \cdot v\right)}{\color{blue}{\left(\pi \cdot t\right) \cdot \left(\sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)} \cdot \left(1 - v \cdot v\right)\right)}} \]
    2. associate-*r*99.4%

      \[\leadsto \frac{1 - \color{blue}{\left(5 \cdot v\right) \cdot v}}{\left(\pi \cdot t\right) \cdot \left(\sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)} \cdot \left(1 - v \cdot v\right)\right)} \]
    3. *-commutative99.4%

      \[\leadsto \frac{1 - \color{blue}{v \cdot \left(5 \cdot v\right)}}{\left(\pi \cdot t\right) \cdot \left(\sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)} \cdot \left(1 - v \cdot v\right)\right)} \]
    4. *-commutative99.4%

      \[\leadsto \frac{1 - v \cdot \left(5 \cdot v\right)}{\color{blue}{\left(\sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)} \cdot \left(1 - v \cdot v\right)\right) \cdot \left(\pi \cdot t\right)}} \]
    5. associate-*l*99.4%

      \[\leadsto \frac{1 - v \cdot \left(5 \cdot v\right)}{\color{blue}{\sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)} \cdot \left(\left(1 - v \cdot v\right) \cdot \left(\pi \cdot t\right)\right)}} \]
  3. Simplified99.4%

    \[\leadsto \color{blue}{\frac{1 - v \cdot \left(5 \cdot v\right)}{\sqrt{2 + 2 \cdot \left(\left(-3 \cdot v\right) \cdot v\right)} \cdot \left(\left(\pi \cdot t\right) \cdot \left(1 - v \cdot v\right)\right)}} \]
  4. Step-by-step derivation
    1. add-sqr-sqrt45.3%

      \[\leadsto \frac{1 - v \cdot \left(5 \cdot v\right)}{\sqrt{2 + 2 \cdot \left(\left(-3 \cdot v\right) \cdot v\right)} \cdot \left(\color{blue}{\left(\sqrt{\pi \cdot t} \cdot \sqrt{\pi \cdot t}\right)} \cdot \left(1 - v \cdot v\right)\right)} \]
    2. pow245.3%

      \[\leadsto \frac{1 - v \cdot \left(5 \cdot v\right)}{\sqrt{2 + 2 \cdot \left(\left(-3 \cdot v\right) \cdot v\right)} \cdot \left(\color{blue}{{\left(\sqrt{\pi \cdot t}\right)}^{2}} \cdot \left(1 - v \cdot v\right)\right)} \]
    3. *-commutative45.3%

      \[\leadsto \frac{1 - v \cdot \left(5 \cdot v\right)}{\sqrt{2 + 2 \cdot \left(\left(-3 \cdot v\right) \cdot v\right)} \cdot \left({\left(\sqrt{\color{blue}{t \cdot \pi}}\right)}^{2} \cdot \left(1 - v \cdot v\right)\right)} \]
  5. Applied egg-rr45.3%

    \[\leadsto \frac{1 - v \cdot \left(5 \cdot v\right)}{\sqrt{2 + 2 \cdot \left(\left(-3 \cdot v\right) \cdot v\right)} \cdot \left(\color{blue}{{\left(\sqrt{t \cdot \pi}\right)}^{2}} \cdot \left(1 - v \cdot v\right)\right)} \]
  6. Taylor expanded in v around 0 97.1%

    \[\leadsto \color{blue}{\frac{\sqrt{0.5}}{t \cdot \pi}} \]
  7. Step-by-step derivation
    1. associate-/r*97.1%

      \[\leadsto \color{blue}{\frac{\frac{\sqrt{0.5}}{t}}{\pi}} \]
  8. Simplified97.1%

    \[\leadsto \color{blue}{\frac{\frac{\sqrt{0.5}}{t}}{\pi}} \]
  9. Final simplification97.1%

    \[\leadsto \frac{\frac{\sqrt{0.5}}{t}}{\pi} \]

Reproduce

?
herbie shell --seed 2023334 
(FPCore (v t)
  :name "Falkner and Boettcher, Equation (20:1,3)"
  :precision binary64
  (/ (- 1.0 (* 5.0 (* v v))) (* (* (* PI t) (sqrt (* 2.0 (- 1.0 (* 3.0 (* v v)))))) (- 1.0 (* v v)))))