
(FPCore (x) :precision binary64 (- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))
double code(double x) {
return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / (x + 1.0d0)) - (1.0d0 / (x - 1.0d0))
end function
public static double code(double x) {
return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0));
}
def code(x): return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0))
function code(x) return Float64(Float64(1.0 / Float64(x + 1.0)) - Float64(1.0 / Float64(x - 1.0))) end
function tmp = code(x) tmp = (1.0 / (x + 1.0)) - (1.0 / (x - 1.0)); end
code[x_] := N[(N[(1.0 / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x + 1} - \frac{1}{x - 1}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))
double code(double x) {
return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / (x + 1.0d0)) - (1.0d0 / (x - 1.0d0))
end function
public static double code(double x) {
return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0));
}
def code(x): return (1.0 / (x + 1.0)) - (1.0 / (x - 1.0))
function code(x) return Float64(Float64(1.0 / Float64(x + 1.0)) - Float64(1.0 / Float64(x - 1.0))) end
function tmp = code(x) tmp = (1.0 / (x + 1.0)) - (1.0 / (x - 1.0)); end
code[x_] := N[(N[(1.0 / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x + 1} - \frac{1}{x - 1}
\end{array}
(FPCore (x) :precision binary64 (/ (/ 2.0 (- -1.0 x)) (+ -1.0 x)))
double code(double x) {
return (2.0 / (-1.0 - x)) / (-1.0 + x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = (2.0d0 / ((-1.0d0) - x)) / ((-1.0d0) + x)
end function
public static double code(double x) {
return (2.0 / (-1.0 - x)) / (-1.0 + x);
}
def code(x): return (2.0 / (-1.0 - x)) / (-1.0 + x)
function code(x) return Float64(Float64(2.0 / Float64(-1.0 - x)) / Float64(-1.0 + x)) end
function tmp = code(x) tmp = (2.0 / (-1.0 - x)) / (-1.0 + x); end
code[x_] := N[(N[(2.0 / N[(-1.0 - x), $MachinePrecision]), $MachinePrecision] / N[(-1.0 + x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{2}{-1 - x}}{-1 + x}
\end{array}
Initial program 77.5%
frac-sub78.1%
associate-/r*78.1%
*-un-lft-identity78.1%
*-rgt-identity78.1%
associate--l-78.4%
+-commutative78.4%
+-commutative78.4%
sub-neg78.4%
metadata-eval78.4%
Applied egg-rr78.4%
div-sub77.4%
div-sub77.4%
+-commutative77.4%
+-commutative77.4%
associate-+l+77.5%
metadata-eval77.5%
Applied egg-rr77.5%
Simplified99.9%
Final simplification99.9%
(FPCore (x) :precision binary64 (if (<= x 1.55) (+ (- 1.0 x) (/ -1.0 (+ -1.0 x))) (/ (/ -2.0 x) x)))
double code(double x) {
double tmp;
if (x <= 1.55) {
tmp = (1.0 - x) + (-1.0 / (-1.0 + x));
} else {
tmp = (-2.0 / x) / x;
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= 1.55d0) then
tmp = (1.0d0 - x) + ((-1.0d0) / ((-1.0d0) + x))
else
tmp = ((-2.0d0) / x) / x
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= 1.55) {
tmp = (1.0 - x) + (-1.0 / (-1.0 + x));
} else {
tmp = (-2.0 / x) / x;
}
return tmp;
}
def code(x): tmp = 0 if x <= 1.55: tmp = (1.0 - x) + (-1.0 / (-1.0 + x)) else: tmp = (-2.0 / x) / x return tmp
function code(x) tmp = 0.0 if (x <= 1.55) tmp = Float64(Float64(1.0 - x) + Float64(-1.0 / Float64(-1.0 + x))); else tmp = Float64(Float64(-2.0 / x) / x); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= 1.55) tmp = (1.0 - x) + (-1.0 / (-1.0 + x)); else tmp = (-2.0 / x) / x; end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, 1.55], N[(N[(1.0 - x), $MachinePrecision] + N[(-1.0 / N[(-1.0 + x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(-2.0 / x), $MachinePrecision] / x), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.55:\\
\;\;\;\;\left(1 - x\right) + \frac{-1}{-1 + x}\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{-2}{x}}{x}\\
\end{array}
\end{array}
if x < 1.55000000000000004Initial program 83.6%
Taylor expanded in x around 0 65.8%
neg-mul-165.8%
unsub-neg65.8%
Simplified65.8%
if 1.55000000000000004 < x Initial program 58.4%
Taylor expanded in x around inf 98.3%
unpow298.3%
Simplified98.3%
frac-2neg98.3%
metadata-eval98.3%
div-inv98.3%
distribute-rgt-neg-in98.3%
Applied egg-rr98.3%
metadata-eval98.3%
associate-/r*99.8%
times-frac99.8%
neg-mul-199.8%
remove-double-neg99.8%
associate-*l/99.8%
associate-*r/99.8%
*-rgt-identity99.8%
Simplified99.8%
Final simplification74.1%
(FPCore (x) :precision binary64 (if (<= x 1.0) (+ 2.0 (* x x)) (/ -2.0 (* x x))))
double code(double x) {
double tmp;
if (x <= 1.0) {
tmp = 2.0 + (x * x);
} else {
tmp = -2.0 / (x * x);
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= 1.0d0) then
tmp = 2.0d0 + (x * x)
else
tmp = (-2.0d0) / (x * x)
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= 1.0) {
tmp = 2.0 + (x * x);
} else {
tmp = -2.0 / (x * x);
}
return tmp;
}
def code(x): tmp = 0 if x <= 1.0: tmp = 2.0 + (x * x) else: tmp = -2.0 / (x * x) return tmp
function code(x) tmp = 0.0 if (x <= 1.0) tmp = Float64(2.0 + Float64(x * x)); else tmp = Float64(-2.0 / Float64(x * x)); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= 1.0) tmp = 2.0 + (x * x); else tmp = -2.0 / (x * x); end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, 1.0], N[(2.0 + N[(x * x), $MachinePrecision]), $MachinePrecision], N[(-2.0 / N[(x * x), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq 1:\\
\;\;\;\;2 + x \cdot x\\
\mathbf{else}:\\
\;\;\;\;\frac{-2}{x \cdot x}\\
\end{array}
\end{array}
if x < 1Initial program 83.6%
Taylor expanded in x around 0 65.8%
neg-mul-165.8%
unsub-neg65.8%
Simplified65.8%
Taylor expanded in x around 0 65.7%
unpow265.7%
Simplified65.7%
if 1 < x Initial program 58.4%
Taylor expanded in x around inf 98.3%
unpow298.3%
Simplified98.3%
Final simplification73.6%
(FPCore (x) :precision binary64 (if (<= x 1.0) (+ 2.0 (* x x)) (/ (/ -2.0 x) x)))
double code(double x) {
double tmp;
if (x <= 1.0) {
tmp = 2.0 + (x * x);
} else {
tmp = (-2.0 / x) / x;
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= 1.0d0) then
tmp = 2.0d0 + (x * x)
else
tmp = ((-2.0d0) / x) / x
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= 1.0) {
tmp = 2.0 + (x * x);
} else {
tmp = (-2.0 / x) / x;
}
return tmp;
}
def code(x): tmp = 0 if x <= 1.0: tmp = 2.0 + (x * x) else: tmp = (-2.0 / x) / x return tmp
function code(x) tmp = 0.0 if (x <= 1.0) tmp = Float64(2.0 + Float64(x * x)); else tmp = Float64(Float64(-2.0 / x) / x); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= 1.0) tmp = 2.0 + (x * x); else tmp = (-2.0 / x) / x; end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, 1.0], N[(2.0 + N[(x * x), $MachinePrecision]), $MachinePrecision], N[(N[(-2.0 / x), $MachinePrecision] / x), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq 1:\\
\;\;\;\;2 + x \cdot x\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{-2}{x}}{x}\\
\end{array}
\end{array}
if x < 1Initial program 83.6%
Taylor expanded in x around 0 65.8%
neg-mul-165.8%
unsub-neg65.8%
Simplified65.8%
Taylor expanded in x around 0 65.7%
unpow265.7%
Simplified65.7%
if 1 < x Initial program 58.4%
Taylor expanded in x around inf 98.3%
unpow298.3%
Simplified98.3%
frac-2neg98.3%
metadata-eval98.3%
div-inv98.3%
distribute-rgt-neg-in98.3%
Applied egg-rr98.3%
metadata-eval98.3%
associate-/r*99.8%
times-frac99.8%
neg-mul-199.8%
remove-double-neg99.8%
associate-*l/99.8%
associate-*r/99.8%
*-rgt-identity99.8%
Simplified99.8%
Final simplification74.0%
(FPCore (x) :precision binary64 2.0)
double code(double x) {
return 2.0;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 2.0d0
end function
public static double code(double x) {
return 2.0;
}
def code(x): return 2.0
function code(x) return 2.0 end
function tmp = code(x) tmp = 2.0; end
code[x_] := 2.0
\begin{array}{l}
\\
2
\end{array}
Initial program 77.5%
Taylor expanded in x around 0 50.7%
Final simplification50.7%
herbie shell --seed 2023238
(FPCore (x)
:name "Asymptote A"
:precision binary64
(- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))