
(FPCore (x) :precision binary64 (* (/ 1.0 2.0) (log (/ (+ 1.0 x) (- 1.0 x)))))
double code(double x) {
return (1.0 / 2.0) * log(((1.0 + x) / (1.0 - x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / 2.0d0) * log(((1.0d0 + x) / (1.0d0 - x)))
end function
public static double code(double x) {
return (1.0 / 2.0) * Math.log(((1.0 + x) / (1.0 - x)));
}
def code(x): return (1.0 / 2.0) * math.log(((1.0 + x) / (1.0 - x)))
function code(x) return Float64(Float64(1.0 / 2.0) * log(Float64(Float64(1.0 + x) / Float64(1.0 - x)))) end
function tmp = code(x) tmp = (1.0 / 2.0) * log(((1.0 + x) / (1.0 - x))); end
code[x_] := N[(N[(1.0 / 2.0), $MachinePrecision] * N[Log[N[(N[(1.0 + x), $MachinePrecision] / N[(1.0 - x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{2} \cdot \log \left(\frac{1 + x}{1 - x}\right)
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (* (/ 1.0 2.0) (log (/ (+ 1.0 x) (- 1.0 x)))))
double code(double x) {
return (1.0 / 2.0) * log(((1.0 + x) / (1.0 - x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / 2.0d0) * log(((1.0d0 + x) / (1.0d0 - x)))
end function
public static double code(double x) {
return (1.0 / 2.0) * Math.log(((1.0 + x) / (1.0 - x)));
}
def code(x): return (1.0 / 2.0) * math.log(((1.0 + x) / (1.0 - x)))
function code(x) return Float64(Float64(1.0 / 2.0) * log(Float64(Float64(1.0 + x) / Float64(1.0 - x)))) end
function tmp = code(x) tmp = (1.0 / 2.0) * log(((1.0 + x) / (1.0 - x))); end
code[x_] := N[(N[(1.0 / 2.0), $MachinePrecision] * N[Log[N[(N[(1.0 + x), $MachinePrecision] / N[(1.0 - x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{2} \cdot \log \left(\frac{1 + x}{1 - x}\right)
\end{array}
(FPCore (x) :precision binary64 (* 0.5 (- (* 2.0 (log1p x)) (log1p (- (* x x))))))
double code(double x) {
return 0.5 * ((2.0 * log1p(x)) - log1p(-(x * x)));
}
public static double code(double x) {
return 0.5 * ((2.0 * Math.log1p(x)) - Math.log1p(-(x * x)));
}
def code(x): return 0.5 * ((2.0 * math.log1p(x)) - math.log1p(-(x * x)))
function code(x) return Float64(0.5 * Float64(Float64(2.0 * log1p(x)) - log1p(Float64(-Float64(x * x))))) end
code[x_] := N[(0.5 * N[(N[(2.0 * N[Log[1 + x], $MachinePrecision]), $MachinePrecision] - N[Log[1 + (-N[(x * x), $MachinePrecision])], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 \cdot \left(2 \cdot \mathsf{log1p}\left(x\right) - \mathsf{log1p}\left(-x \cdot x\right)\right)
\end{array}
Initial program 7.6%
Simplified0
Applied egg-rr0
(FPCore (x)
:precision binary64
(let* ((t_0 (* x (* x (* x x))))
(t_1 (+ 0.1111111111111111 (* x (* x 0.13333333333333333)))))
(/
(*
(/
(- 1.0 (* (* t_0 t_0) (* t_1 t_1)))
(+ 1.0 (* x (* x (* (* x x) t_1)))))
x)
(-
1.0
(*
x
(*
x
(+
0.3333333333333333
(* (* x x) (+ 0.2 (* x (* x 0.14285714285714285)))))))))))
double code(double x) {
double t_0 = x * (x * (x * x));
double t_1 = 0.1111111111111111 + (x * (x * 0.13333333333333333));
return (((1.0 - ((t_0 * t_0) * (t_1 * t_1))) / (1.0 + (x * (x * ((x * x) * t_1))))) * x) / (1.0 - (x * (x * (0.3333333333333333 + ((x * x) * (0.2 + (x * (x * 0.14285714285714285))))))));
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: t_0
real(8) :: t_1
t_0 = x * (x * (x * x))
t_1 = 0.1111111111111111d0 + (x * (x * 0.13333333333333333d0))
code = (((1.0d0 - ((t_0 * t_0) * (t_1 * t_1))) / (1.0d0 + (x * (x * ((x * x) * t_1))))) * x) / (1.0d0 - (x * (x * (0.3333333333333333d0 + ((x * x) * (0.2d0 + (x * (x * 0.14285714285714285d0))))))))
end function
public static double code(double x) {
double t_0 = x * (x * (x * x));
double t_1 = 0.1111111111111111 + (x * (x * 0.13333333333333333));
return (((1.0 - ((t_0 * t_0) * (t_1 * t_1))) / (1.0 + (x * (x * ((x * x) * t_1))))) * x) / (1.0 - (x * (x * (0.3333333333333333 + ((x * x) * (0.2 + (x * (x * 0.14285714285714285))))))));
}
def code(x): t_0 = x * (x * (x * x)) t_1 = 0.1111111111111111 + (x * (x * 0.13333333333333333)) return (((1.0 - ((t_0 * t_0) * (t_1 * t_1))) / (1.0 + (x * (x * ((x * x) * t_1))))) * x) / (1.0 - (x * (x * (0.3333333333333333 + ((x * x) * (0.2 + (x * (x * 0.14285714285714285))))))))
function code(x) t_0 = Float64(x * Float64(x * Float64(x * x))) t_1 = Float64(0.1111111111111111 + Float64(x * Float64(x * 0.13333333333333333))) return Float64(Float64(Float64(Float64(1.0 - Float64(Float64(t_0 * t_0) * Float64(t_1 * t_1))) / Float64(1.0 + Float64(x * Float64(x * Float64(Float64(x * x) * t_1))))) * x) / Float64(1.0 - Float64(x * Float64(x * Float64(0.3333333333333333 + Float64(Float64(x * x) * Float64(0.2 + Float64(x * Float64(x * 0.14285714285714285))))))))) end
function tmp = code(x) t_0 = x * (x * (x * x)); t_1 = 0.1111111111111111 + (x * (x * 0.13333333333333333)); tmp = (((1.0 - ((t_0 * t_0) * (t_1 * t_1))) / (1.0 + (x * (x * ((x * x) * t_1))))) * x) / (1.0 - (x * (x * (0.3333333333333333 + ((x * x) * (0.2 + (x * (x * 0.14285714285714285)))))))); end
code[x_] := Block[{t$95$0 = N[(x * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(0.1111111111111111 + N[(x * N[(x * 0.13333333333333333), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(N[(1.0 - N[(N[(t$95$0 * t$95$0), $MachinePrecision] * N[(t$95$1 * t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[(x * N[(x * N[(N[(x * x), $MachinePrecision] * t$95$1), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * x), $MachinePrecision] / N[(1.0 - N[(x * N[(x * N[(0.3333333333333333 + N[(N[(x * x), $MachinePrecision] * N[(0.2 + N[(x * N[(x * 0.14285714285714285), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := x \cdot \left(x \cdot \left(x \cdot x\right)\right)\\
t_1 := 0.1111111111111111 + x \cdot \left(x \cdot 0.13333333333333333\right)\\
\frac{\frac{1 - \left(t\_0 \cdot t\_0\right) \cdot \left(t\_1 \cdot t\_1\right)}{1 + x \cdot \left(x \cdot \left(\left(x \cdot x\right) \cdot t\_1\right)\right)} \cdot x}{1 - x \cdot \left(x \cdot \left(0.3333333333333333 + \left(x \cdot x\right) \cdot \left(0.2 + x \cdot \left(x \cdot 0.14285714285714285\right)\right)\right)\right)}
\end{array}
\end{array}
Initial program 7.6%
Simplified0
Taylor expanded in x around 0 0
Simplified0
Applied egg-rr0
Taylor expanded in x around 0 0
Simplified0
Applied egg-rr0
(FPCore (x)
:precision binary64
(*
(/
x
(-
1.0
(*
x
(*
x
(+
0.3333333333333333
(* x (* x (+ 0.2 (* x (* x 0.14285714285714285))))))))))
(-
1.0
(*
x
(*
x
(* (* x x) (+ 0.1111111111111111 (* x (* x 0.13333333333333333)))))))))
double code(double x) {
return (x / (1.0 - (x * (x * (0.3333333333333333 + (x * (x * (0.2 + (x * (x * 0.14285714285714285)))))))))) * (1.0 - (x * (x * ((x * x) * (0.1111111111111111 + (x * (x * 0.13333333333333333)))))));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x / (1.0d0 - (x * (x * (0.3333333333333333d0 + (x * (x * (0.2d0 + (x * (x * 0.14285714285714285d0)))))))))) * (1.0d0 - (x * (x * ((x * x) * (0.1111111111111111d0 + (x * (x * 0.13333333333333333d0)))))))
end function
public static double code(double x) {
return (x / (1.0 - (x * (x * (0.3333333333333333 + (x * (x * (0.2 + (x * (x * 0.14285714285714285)))))))))) * (1.0 - (x * (x * ((x * x) * (0.1111111111111111 + (x * (x * 0.13333333333333333)))))));
}
def code(x): return (x / (1.0 - (x * (x * (0.3333333333333333 + (x * (x * (0.2 + (x * (x * 0.14285714285714285)))))))))) * (1.0 - (x * (x * ((x * x) * (0.1111111111111111 + (x * (x * 0.13333333333333333)))))))
function code(x) return Float64(Float64(x / Float64(1.0 - Float64(x * Float64(x * Float64(0.3333333333333333 + Float64(x * Float64(x * Float64(0.2 + Float64(x * Float64(x * 0.14285714285714285)))))))))) * Float64(1.0 - Float64(x * Float64(x * Float64(Float64(x * x) * Float64(0.1111111111111111 + Float64(x * Float64(x * 0.13333333333333333)))))))) end
function tmp = code(x) tmp = (x / (1.0 - (x * (x * (0.3333333333333333 + (x * (x * (0.2 + (x * (x * 0.14285714285714285)))))))))) * (1.0 - (x * (x * ((x * x) * (0.1111111111111111 + (x * (x * 0.13333333333333333))))))); end
code[x_] := N[(N[(x / N[(1.0 - N[(x * N[(x * N[(0.3333333333333333 + N[(x * N[(x * N[(0.2 + N[(x * N[(x * 0.14285714285714285), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(1.0 - N[(x * N[(x * N[(N[(x * x), $MachinePrecision] * N[(0.1111111111111111 + N[(x * N[(x * 0.13333333333333333), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x}{1 - x \cdot \left(x \cdot \left(0.3333333333333333 + x \cdot \left(x \cdot \left(0.2 + x \cdot \left(x \cdot 0.14285714285714285\right)\right)\right)\right)\right)} \cdot \left(1 - x \cdot \left(x \cdot \left(\left(x \cdot x\right) \cdot \left(0.1111111111111111 + x \cdot \left(x \cdot 0.13333333333333333\right)\right)\right)\right)\right)
\end{array}
Initial program 7.6%
Simplified0
Taylor expanded in x around 0 0
Simplified0
Applied egg-rr0
Taylor expanded in x around 0 0
Simplified0
Applied egg-rr0
(FPCore (x)
:precision binary64
(*
x
(+
1.0
(*
x
(*
x
(+
0.3333333333333333
(* (* x x) (+ 0.2 (* (* x x) 0.14285714285714285)))))))))
double code(double x) {
return x * (1.0 + (x * (x * (0.3333333333333333 + ((x * x) * (0.2 + ((x * x) * 0.14285714285714285)))))));
}
real(8) function code(x)
real(8), intent (in) :: x
code = x * (1.0d0 + (x * (x * (0.3333333333333333d0 + ((x * x) * (0.2d0 + ((x * x) * 0.14285714285714285d0)))))))
end function
public static double code(double x) {
return x * (1.0 + (x * (x * (0.3333333333333333 + ((x * x) * (0.2 + ((x * x) * 0.14285714285714285)))))));
}
def code(x): return x * (1.0 + (x * (x * (0.3333333333333333 + ((x * x) * (0.2 + ((x * x) * 0.14285714285714285)))))))
function code(x) return Float64(x * Float64(1.0 + Float64(x * Float64(x * Float64(0.3333333333333333 + Float64(Float64(x * x) * Float64(0.2 + Float64(Float64(x * x) * 0.14285714285714285)))))))) end
function tmp = code(x) tmp = x * (1.0 + (x * (x * (0.3333333333333333 + ((x * x) * (0.2 + ((x * x) * 0.14285714285714285))))))); end
code[x_] := N[(x * N[(1.0 + N[(x * N[(x * N[(0.3333333333333333 + N[(N[(x * x), $MachinePrecision] * N[(0.2 + N[(N[(x * x), $MachinePrecision] * 0.14285714285714285), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \left(1 + x \cdot \left(x \cdot \left(0.3333333333333333 + \left(x \cdot x\right) \cdot \left(0.2 + \left(x \cdot x\right) \cdot 0.14285714285714285\right)\right)\right)\right)
\end{array}
Initial program 7.6%
Simplified0
Taylor expanded in x around 0 0
Simplified0
(FPCore (x) :precision binary64 (* x (+ 1.0 (* (* x x) (+ 0.3333333333333333 (* (* x x) 0.2))))))
double code(double x) {
return x * (1.0 + ((x * x) * (0.3333333333333333 + ((x * x) * 0.2))));
}
real(8) function code(x)
real(8), intent (in) :: x
code = x * (1.0d0 + ((x * x) * (0.3333333333333333d0 + ((x * x) * 0.2d0))))
end function
public static double code(double x) {
return x * (1.0 + ((x * x) * (0.3333333333333333 + ((x * x) * 0.2))));
}
def code(x): return x * (1.0 + ((x * x) * (0.3333333333333333 + ((x * x) * 0.2))))
function code(x) return Float64(x * Float64(1.0 + Float64(Float64(x * x) * Float64(0.3333333333333333 + Float64(Float64(x * x) * 0.2))))) end
function tmp = code(x) tmp = x * (1.0 + ((x * x) * (0.3333333333333333 + ((x * x) * 0.2)))); end
code[x_] := N[(x * N[(1.0 + N[(N[(x * x), $MachinePrecision] * N[(0.3333333333333333 + N[(N[(x * x), $MachinePrecision] * 0.2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \left(1 + \left(x \cdot x\right) \cdot \left(0.3333333333333333 + \left(x \cdot x\right) \cdot 0.2\right)\right)
\end{array}
Initial program 7.6%
Simplified0
Taylor expanded in x around 0 0
Simplified0
(FPCore (x) :precision binary64 (+ (* (* x x) (* x 0.3333333333333333)) x))
double code(double x) {
return ((x * x) * (x * 0.3333333333333333)) + x;
}
real(8) function code(x)
real(8), intent (in) :: x
code = ((x * x) * (x * 0.3333333333333333d0)) + x
end function
public static double code(double x) {
return ((x * x) * (x * 0.3333333333333333)) + x;
}
def code(x): return ((x * x) * (x * 0.3333333333333333)) + x
function code(x) return Float64(Float64(Float64(x * x) * Float64(x * 0.3333333333333333)) + x) end
function tmp = code(x) tmp = ((x * x) * (x * 0.3333333333333333)) + x; end
code[x_] := N[(N[(N[(x * x), $MachinePrecision] * N[(x * 0.3333333333333333), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision]
\begin{array}{l}
\\
\left(x \cdot x\right) \cdot \left(x \cdot 0.3333333333333333\right) + x
\end{array}
Initial program 7.6%
Simplified0
Taylor expanded in x around 0 0
Simplified0
Applied egg-rr0
(FPCore (x) :precision binary64 (* x (+ 1.0 (* x (* x 0.3333333333333333)))))
double code(double x) {
return x * (1.0 + (x * (x * 0.3333333333333333)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = x * (1.0d0 + (x * (x * 0.3333333333333333d0)))
end function
public static double code(double x) {
return x * (1.0 + (x * (x * 0.3333333333333333)));
}
def code(x): return x * (1.0 + (x * (x * 0.3333333333333333)))
function code(x) return Float64(x * Float64(1.0 + Float64(x * Float64(x * 0.3333333333333333)))) end
function tmp = code(x) tmp = x * (1.0 + (x * (x * 0.3333333333333333))); end
code[x_] := N[(x * N[(1.0 + N[(x * N[(x * 0.3333333333333333), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
x \cdot \left(1 + x \cdot \left(x \cdot 0.3333333333333333\right)\right)
\end{array}
Initial program 7.6%
Simplified0
Taylor expanded in x around 0 0
Simplified0
(FPCore (x) :precision binary64 x)
double code(double x) {
return x;
}
real(8) function code(x)
real(8), intent (in) :: x
code = x
end function
public static double code(double x) {
return x;
}
def code(x): return x
function code(x) return x end
function tmp = code(x) tmp = x; end
code[x_] := x
\begin{array}{l}
\\
x
\end{array}
Initial program 7.6%
Simplified0
Taylor expanded in x around 0 0
Simplified0
herbie shell --seed 2024110
(FPCore (x)
:name "Hyperbolic arc-(co)tangent"
:precision binary64
(* (/ 1.0 2.0) (log (/ (+ 1.0 x) (- 1.0 x)))))