
(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 77.9%
sub-neg77.9%
+-commutative77.9%
distribute-neg-frac77.9%
metadata-eval77.9%
metadata-eval77.9%
metadata-eval77.9%
associate-/r*77.9%
metadata-eval77.9%
neg-mul-177.9%
sub0-neg77.9%
associate-+l-77.9%
neg-sub077.9%
metadata-eval77.9%
metadata-eval77.9%
metadata-eval77.9%
associate-/r*77.9%
metadata-eval77.9%
neg-mul-177.9%
distribute-neg-in77.9%
sub-neg77.9%
distribute-neg-frac77.9%
neg-mul-177.9%
Simplified77.9%
sub-neg77.9%
distribute-neg-frac77.9%
metadata-eval77.9%
Applied egg-rr77.9%
Simplified99.6%
clear-num99.6%
inv-pow99.6%
*-commutative99.6%
associate-/l*99.6%
Applied egg-rr99.6%
unpow-199.6%
clear-num99.9%
Applied egg-rr99.9%
Final simplification99.9%
(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(-2.0 / Float64(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[(-2.0 / N[(N[(1.0 - x), $MachinePrecision] * N[(-1.0 - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{-2}{\left(1 - x\right) \cdot \left(-1 - x\right)}
\end{array}
Initial program 77.9%
sub-neg77.9%
+-commutative77.9%
distribute-neg-frac77.9%
metadata-eval77.9%
metadata-eval77.9%
metadata-eval77.9%
associate-/r*77.9%
metadata-eval77.9%
neg-mul-177.9%
sub0-neg77.9%
associate-+l-77.9%
neg-sub077.9%
metadata-eval77.9%
metadata-eval77.9%
metadata-eval77.9%
associate-/r*77.9%
metadata-eval77.9%
neg-mul-177.9%
distribute-neg-in77.9%
sub-neg77.9%
distribute-neg-frac77.9%
neg-mul-177.9%
Simplified77.9%
sub-neg77.9%
distribute-neg-frac77.9%
metadata-eval77.9%
Applied egg-rr77.9%
Simplified99.6%
Final simplification99.6%
(FPCore (x) :precision binary64 (if (<= x 1.0) 2.0 0.0))
double code(double x) {
double tmp;
if (x <= 1.0) {
tmp = 2.0;
} else {
tmp = 0.0;
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= 1.0d0) then
tmp = 2.0d0
else
tmp = 0.0d0
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= 1.0) {
tmp = 2.0;
} else {
tmp = 0.0;
}
return tmp;
}
def code(x): tmp = 0 if x <= 1.0: tmp = 2.0 else: tmp = 0.0 return tmp
function code(x) tmp = 0.0 if (x <= 1.0) tmp = 2.0; else tmp = 0.0; end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= 1.0) tmp = 2.0; else tmp = 0.0; end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, 1.0], 2.0, 0.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq 1:\\
\;\;\;\;2\\
\mathbf{else}:\\
\;\;\;\;0\\
\end{array}
\end{array}
if x < 1Initial program 85.2%
sub-neg85.2%
+-commutative85.2%
distribute-neg-frac85.2%
metadata-eval85.2%
metadata-eval85.2%
metadata-eval85.2%
associate-/r*85.2%
metadata-eval85.2%
neg-mul-185.2%
sub0-neg85.2%
associate-+l-85.2%
neg-sub085.2%
metadata-eval85.2%
metadata-eval85.2%
metadata-eval85.2%
associate-/r*85.2%
metadata-eval85.2%
neg-mul-185.2%
distribute-neg-in85.2%
sub-neg85.2%
distribute-neg-frac85.2%
neg-mul-185.2%
Simplified85.2%
Taylor expanded in x around 0 68.4%
if 1 < x Initial program 57.9%
sub-neg57.9%
+-commutative57.9%
distribute-neg-frac57.9%
metadata-eval57.9%
metadata-eval57.9%
metadata-eval57.9%
associate-/r*57.9%
metadata-eval57.9%
neg-mul-157.9%
sub0-neg57.9%
associate-+l-57.9%
neg-sub057.9%
metadata-eval57.9%
metadata-eval57.9%
metadata-eval57.9%
associate-/r*57.9%
metadata-eval57.9%
neg-mul-157.9%
distribute-neg-in57.9%
sub-neg57.9%
distribute-neg-frac57.9%
neg-mul-157.9%
Simplified57.9%
sub-neg57.9%
distribute-neg-frac57.9%
metadata-eval57.9%
Applied egg-rr57.9%
Simplified98.9%
*-un-lft-identity98.9%
*-commutative98.9%
associate-/r*99.8%
Applied egg-rr99.8%
Applied egg-rr56.0%
Final simplification65.1%
(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 77.9%
sub-neg77.9%
+-commutative77.9%
distribute-neg-frac77.9%
metadata-eval77.9%
metadata-eval77.9%
metadata-eval77.9%
associate-/r*77.9%
metadata-eval77.9%
neg-mul-177.9%
sub0-neg77.9%
associate-+l-77.9%
neg-sub077.9%
metadata-eval77.9%
metadata-eval77.9%
metadata-eval77.9%
associate-/r*77.9%
metadata-eval77.9%
neg-mul-177.9%
distribute-neg-in77.9%
sub-neg77.9%
distribute-neg-frac77.9%
neg-mul-177.9%
Simplified77.9%
Taylor expanded in x around 0 50.3%
Taylor expanded in x around inf 10.7%
Final simplification10.7%
(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 77.9%
sub-neg77.9%
+-commutative77.9%
distribute-neg-frac77.9%
metadata-eval77.9%
metadata-eval77.9%
metadata-eval77.9%
associate-/r*77.9%
metadata-eval77.9%
neg-mul-177.9%
sub0-neg77.9%
associate-+l-77.9%
neg-sub077.9%
metadata-eval77.9%
metadata-eval77.9%
metadata-eval77.9%
associate-/r*77.9%
metadata-eval77.9%
neg-mul-177.9%
distribute-neg-in77.9%
sub-neg77.9%
distribute-neg-frac77.9%
neg-mul-177.9%
Simplified77.9%
Taylor expanded in x around 0 51.0%
Final simplification51.0%
herbie shell --seed 2024041
(FPCore (x)
:name "Asymptote A"
:precision binary64
(- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))