
(FPCore (x) :precision binary64 (- (/ x (+ x 1.0)) (/ (+ x 1.0) (- x 1.0))))
double code(double x) {
return (x / (x + 1.0)) - ((x + 1.0) / (x - 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x / (x + 1.0d0)) - ((x + 1.0d0) / (x - 1.0d0))
end function
public static double code(double x) {
return (x / (x + 1.0)) - ((x + 1.0) / (x - 1.0));
}
def code(x): return (x / (x + 1.0)) - ((x + 1.0) / (x - 1.0))
function code(x) return Float64(Float64(x / Float64(x + 1.0)) - Float64(Float64(x + 1.0) / Float64(x - 1.0))) end
function tmp = code(x) tmp = (x / (x + 1.0)) - ((x + 1.0) / (x - 1.0)); end
code[x_] := N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(N[(x + 1.0), $MachinePrecision] / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x}{x + 1} - \frac{x + 1}{x - 1}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (- (/ x (+ x 1.0)) (/ (+ x 1.0) (- x 1.0))))
double code(double x) {
return (x / (x + 1.0)) - ((x + 1.0) / (x - 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (x / (x + 1.0d0)) - ((x + 1.0d0) / (x - 1.0d0))
end function
public static double code(double x) {
return (x / (x + 1.0)) - ((x + 1.0) / (x - 1.0));
}
def code(x): return (x / (x + 1.0)) - ((x + 1.0) / (x - 1.0))
function code(x) return Float64(Float64(x / Float64(x + 1.0)) - Float64(Float64(x + 1.0) / Float64(x - 1.0))) end
function tmp = code(x) tmp = (x / (x + 1.0)) - ((x + 1.0) / (x - 1.0)); end
code[x_] := N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(N[(x + 1.0), $MachinePrecision] / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{x}{x + 1} - \frac{x + 1}{x - 1}
\end{array}
(FPCore (x) :precision binary64 (let* ((t_0 (+ (/ x (+ x 1.0)) (/ (- -1.0 x) (+ x -1.0))))) (if (<= t_0 2e-15) (/ (+ -3.0 (/ -1.0 x)) x) t_0)))
double code(double x) {
double t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
double tmp;
if (t_0 <= 2e-15) {
tmp = (-3.0 + (-1.0 / x)) / x;
} else {
tmp = t_0;
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: t_0
real(8) :: tmp
t_0 = (x / (x + 1.0d0)) + (((-1.0d0) - x) / (x + (-1.0d0)))
if (t_0 <= 2d-15) then
tmp = ((-3.0d0) + ((-1.0d0) / x)) / x
else
tmp = t_0
end if
code = tmp
end function
public static double code(double x) {
double t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0));
double tmp;
if (t_0 <= 2e-15) {
tmp = (-3.0 + (-1.0 / x)) / x;
} else {
tmp = t_0;
}
return tmp;
}
def code(x): t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0)) tmp = 0 if t_0 <= 2e-15: tmp = (-3.0 + (-1.0 / x)) / x else: tmp = t_0 return tmp
function code(x) t_0 = Float64(Float64(x / Float64(x + 1.0)) + Float64(Float64(-1.0 - x) / Float64(x + -1.0))) tmp = 0.0 if (t_0 <= 2e-15) tmp = Float64(Float64(-3.0 + Float64(-1.0 / x)) / x); else tmp = t_0; end return tmp end
function tmp_2 = code(x) t_0 = (x / (x + 1.0)) + ((-1.0 - x) / (x + -1.0)); tmp = 0.0; if (t_0 <= 2e-15) tmp = (-3.0 + (-1.0 / x)) / x; else tmp = t_0; end tmp_2 = tmp; end
code[x_] := Block[{t$95$0 = N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] + N[(N[(-1.0 - x), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 2e-15], N[(N[(-3.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], t$95$0]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{x}{x + 1} + \frac{-1 - x}{x + -1}\\
\mathbf{if}\;t_0 \leq 2 \cdot 10^{-15}:\\
\;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\
\mathbf{else}:\\
\;\;\;\;t_0\\
\end{array}
\end{array}
if (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1))) < 2.0000000000000002e-15Initial program 7.3%
Taylor expanded in x around inf 99.0%
+-commutative99.0%
distribute-neg-in99.0%
sub-neg99.0%
associate-*r/99.4%
metadata-eval99.4%
distribute-neg-frac99.4%
metadata-eval99.4%
unpow299.4%
associate-/r*99.4%
Simplified99.4%
sub-div99.4%
sub-neg99.4%
distribute-neg-frac99.4%
metadata-eval99.4%
Applied egg-rr99.4%
if 2.0000000000000002e-15 < (-.f64 (/.f64 x (+.f64 x 1)) (/.f64 (+.f64 x 1) (-.f64 x 1))) Initial program 100.0%
Final simplification99.7%
(FPCore (x) :precision binary64 (if (or (<= x -1.0) (not (<= x 1.0))) (/ (+ -3.0 (/ -1.0 x)) x) (+ 1.0 (* x 3.0))))
double code(double x) {
double tmp;
if ((x <= -1.0) || !(x <= 1.0)) {
tmp = (-3.0 + (-1.0 / x)) / x;
} else {
tmp = 1.0 + (x * 3.0);
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if ((x <= (-1.0d0)) .or. (.not. (x <= 1.0d0))) then
tmp = ((-3.0d0) + ((-1.0d0) / x)) / x
else
tmp = 1.0d0 + (x * 3.0d0)
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if ((x <= -1.0) || !(x <= 1.0)) {
tmp = (-3.0 + (-1.0 / x)) / x;
} else {
tmp = 1.0 + (x * 3.0);
}
return tmp;
}
def code(x): tmp = 0 if (x <= -1.0) or not (x <= 1.0): tmp = (-3.0 + (-1.0 / x)) / x else: tmp = 1.0 + (x * 3.0) return tmp
function code(x) tmp = 0.0 if ((x <= -1.0) || !(x <= 1.0)) tmp = Float64(Float64(-3.0 + Float64(-1.0 / x)) / x); else tmp = Float64(1.0 + Float64(x * 3.0)); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if ((x <= -1.0) || ~((x <= 1.0))) tmp = (-3.0 + (-1.0 / x)) / x; else tmp = 1.0 + (x * 3.0); end tmp_2 = tmp; end
code[x_] := If[Or[LessEqual[x, -1.0], N[Not[LessEqual[x, 1.0]], $MachinePrecision]], N[(N[(-3.0 + N[(-1.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], N[(1.0 + N[(x * 3.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\
\;\;\;\;\frac{-3 + \frac{-1}{x}}{x}\\
\mathbf{else}:\\
\;\;\;\;1 + x \cdot 3\\
\end{array}
\end{array}
if x < -1 or 1 < x Initial program 7.3%
Taylor expanded in x around inf 99.0%
+-commutative99.0%
distribute-neg-in99.0%
sub-neg99.0%
associate-*r/99.4%
metadata-eval99.4%
distribute-neg-frac99.4%
metadata-eval99.4%
unpow299.4%
associate-/r*99.4%
Simplified99.4%
sub-div99.4%
sub-neg99.4%
distribute-neg-frac99.4%
metadata-eval99.4%
Applied egg-rr99.4%
if -1 < x < 1Initial program 100.0%
Taylor expanded in x around 0 99.0%
Final simplification99.2%
(FPCore (x) :precision binary64 (if (<= x -1.0) (/ -3.0 x) (if (<= x 1.0) (+ 1.0 (* x 3.0)) (/ -3.0 x))))
double code(double x) {
double tmp;
if (x <= -1.0) {
tmp = -3.0 / x;
} else if (x <= 1.0) {
tmp = 1.0 + (x * 3.0);
} else {
tmp = -3.0 / x;
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= (-1.0d0)) then
tmp = (-3.0d0) / x
else if (x <= 1.0d0) then
tmp = 1.0d0 + (x * 3.0d0)
else
tmp = (-3.0d0) / x
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= -1.0) {
tmp = -3.0 / x;
} else if (x <= 1.0) {
tmp = 1.0 + (x * 3.0);
} else {
tmp = -3.0 / x;
}
return tmp;
}
def code(x): tmp = 0 if x <= -1.0: tmp = -3.0 / x elif x <= 1.0: tmp = 1.0 + (x * 3.0) else: tmp = -3.0 / x return tmp
function code(x) tmp = 0.0 if (x <= -1.0) tmp = Float64(-3.0 / x); elseif (x <= 1.0) tmp = Float64(1.0 + Float64(x * 3.0)); else tmp = Float64(-3.0 / x); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= -1.0) tmp = -3.0 / x; elseif (x <= 1.0) tmp = 1.0 + (x * 3.0); else tmp = -3.0 / x; end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, -1.0], N[(-3.0 / x), $MachinePrecision], If[LessEqual[x, 1.0], N[(1.0 + N[(x * 3.0), $MachinePrecision]), $MachinePrecision], N[(-3.0 / x), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1:\\
\;\;\;\;\frac{-3}{x}\\
\mathbf{elif}\;x \leq 1:\\
\;\;\;\;1 + x \cdot 3\\
\mathbf{else}:\\
\;\;\;\;\frac{-3}{x}\\
\end{array}
\end{array}
if x < -1 or 1 < x Initial program 7.3%
Taylor expanded in x around inf 98.9%
if -1 < x < 1Initial program 100.0%
Taylor expanded in x around 0 99.0%
Final simplification99.0%
(FPCore (x) :precision binary64 (if (<= x -1.0) (/ -3.0 x) (if (<= x 1.0) (- x -1.0) (/ -3.0 x))))
double code(double x) {
double tmp;
if (x <= -1.0) {
tmp = -3.0 / x;
} else if (x <= 1.0) {
tmp = x - -1.0;
} else {
tmp = -3.0 / x;
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= (-1.0d0)) then
tmp = (-3.0d0) / x
else if (x <= 1.0d0) then
tmp = x - (-1.0d0)
else
tmp = (-3.0d0) / x
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= -1.0) {
tmp = -3.0 / x;
} else if (x <= 1.0) {
tmp = x - -1.0;
} else {
tmp = -3.0 / x;
}
return tmp;
}
def code(x): tmp = 0 if x <= -1.0: tmp = -3.0 / x elif x <= 1.0: tmp = x - -1.0 else: tmp = -3.0 / x return tmp
function code(x) tmp = 0.0 if (x <= -1.0) tmp = Float64(-3.0 / x); elseif (x <= 1.0) tmp = Float64(x - -1.0); else tmp = Float64(-3.0 / x); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= -1.0) tmp = -3.0 / x; elseif (x <= 1.0) tmp = x - -1.0; else tmp = -3.0 / x; end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, -1.0], N[(-3.0 / x), $MachinePrecision], If[LessEqual[x, 1.0], N[(x - -1.0), $MachinePrecision], N[(-3.0 / x), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1:\\
\;\;\;\;\frac{-3}{x}\\
\mathbf{elif}\;x \leq 1:\\
\;\;\;\;x - -1\\
\mathbf{else}:\\
\;\;\;\;\frac{-3}{x}\\
\end{array}
\end{array}
if x < -1 or 1 < x Initial program 7.3%
Taylor expanded in x around inf 98.9%
if -1 < x < 1Initial program 100.0%
Taylor expanded in x around 0 99.0%
Taylor expanded in x around 0 97.5%
Final simplification98.2%
(FPCore (x) :precision binary64 1.0)
double code(double x) {
return 1.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0
end function
public static double code(double x) {
return 1.0;
}
def code(x): return 1.0
function code(x) return 1.0 end
function tmp = code(x) tmp = 1.0; end
code[x_] := 1.0
\begin{array}{l}
\\
1
\end{array}
Initial program 55.4%
Taylor expanded in x around 0 52.4%
Final simplification52.4%
herbie shell --seed 2023200
(FPCore (x)
:name "Asymptote C"
:precision binary64
(- (/ x (+ x 1.0)) (/ (+ x 1.0) (- x 1.0))))