
(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 3 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 78.6%
sub-neg78.6%
+-commutative78.6%
neg-sub078.6%
associate-+l-78.6%
sub-neg78.6%
associate--r+78.6%
neg-sub078.6%
distribute-neg-frac78.6%
metadata-eval78.6%
metadata-eval78.6%
metadata-eval78.6%
associate-/r*78.6%
metadata-eval78.6%
neg-mul-178.6%
sub0-neg78.6%
associate-+l-78.6%
neg-sub078.6%
+-commutative78.6%
unsub-neg78.6%
distribute-neg-frac78.6%
metadata-eval78.6%
metadata-eval78.6%
metadata-eval78.6%
associate-/r*78.6%
metadata-eval78.6%
neg-mul-178.6%
Simplified78.6%
sub-neg78.6%
distribute-neg-frac78.6%
metadata-eval78.6%
Applied egg-rr78.6%
Simplified99.6%
*-commutative99.6%
flip--99.6%
associate-*l/90.7%
metadata-eval90.7%
pow290.7%
+-commutative90.7%
Applied egg-rr90.7%
associate-/r/90.6%
*-commutative90.6%
associate-/r*92.0%
metadata-eval92.0%
associate-/r/99.6%
metadata-eval99.6%
unpow299.6%
+-commutative99.6%
flip--99.9%
frac-2neg99.9%
div-inv99.8%
metadata-eval99.8%
distribute-neg-frac99.8%
metadata-eval99.8%
sub-neg99.8%
neg-mul-199.8%
distribute-neg-in99.8%
metadata-eval99.8%
*-commutative99.8%
Applied egg-rr99.8%
associate-*r/99.9%
*-rgt-identity99.9%
sub-neg99.9%
remove-double-neg99.9%
+-commutative99.9%
Simplified99.9%
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 78.6%
sub-neg78.6%
+-commutative78.6%
neg-sub078.6%
associate-+l-78.6%
sub-neg78.6%
associate--r+78.6%
neg-sub078.6%
distribute-neg-frac78.6%
metadata-eval78.6%
metadata-eval78.6%
metadata-eval78.6%
associate-/r*78.6%
metadata-eval78.6%
neg-mul-178.6%
sub0-neg78.6%
associate-+l-78.6%
neg-sub078.6%
+-commutative78.6%
unsub-neg78.6%
distribute-neg-frac78.6%
metadata-eval78.6%
metadata-eval78.6%
metadata-eval78.6%
associate-/r*78.6%
metadata-eval78.6%
neg-mul-178.6%
Simplified78.6%
sub-neg78.6%
distribute-neg-frac78.6%
metadata-eval78.6%
Applied egg-rr78.6%
Simplified99.6%
Final simplification99.6%
(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 78.6%
sub-neg78.6%
+-commutative78.6%
neg-sub078.6%
associate-+l-78.6%
sub-neg78.6%
associate--r+78.6%
neg-sub078.6%
distribute-neg-frac78.6%
metadata-eval78.6%
metadata-eval78.6%
metadata-eval78.6%
associate-/r*78.6%
metadata-eval78.6%
neg-mul-178.6%
sub0-neg78.6%
associate-+l-78.6%
neg-sub078.6%
+-commutative78.6%
unsub-neg78.6%
distribute-neg-frac78.6%
metadata-eval78.6%
metadata-eval78.6%
metadata-eval78.6%
associate-/r*78.6%
metadata-eval78.6%
neg-mul-178.6%
Simplified78.6%
Taylor expanded in x around 0 48.4%
Final simplification48.4%
herbie shell --seed 2023318
(FPCore (x)
:name "Asymptote A"
:precision binary64
(- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))