
(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)) (+ x -1.0)))
double code(double x) {
return (-2.0 / (1.0 + x)) / (x + -1.0);
}
real(8) function code(x)
real(8), intent (in) :: x
code = ((-2.0d0) / (1.0d0 + x)) / (x + (-1.0d0))
end function
public static double code(double x) {
return (-2.0 / (1.0 + x)) / (x + -1.0);
}
def code(x): return (-2.0 / (1.0 + x)) / (x + -1.0)
function code(x) return Float64(Float64(-2.0 / Float64(1.0 + x)) / Float64(x + -1.0)) end
function tmp = code(x) tmp = (-2.0 / (1.0 + x)) / (x + -1.0); end
code[x_] := N[(N[(-2.0 / N[(1.0 + x), $MachinePrecision]), $MachinePrecision] / N[(x + -1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{-2}{1 + x}}{x + -1}
\end{array}
Initial program 76.4%
frac-sub77.2%
associate-/r*77.2%
*-un-lft-identity77.2%
*-rgt-identity77.2%
associate--l-77.2%
+-commutative77.2%
+-commutative77.2%
sub-neg77.2%
metadata-eval77.2%
Applied egg-rr77.2%
Taylor expanded in x around 0 99.9%
Final simplification99.9%
(FPCore (x) :precision binary64 (if (or (<= x -1.0) (not (<= x 1.0))) (/ -2.0 (* x x)) 2.0))
double code(double x) {
double tmp;
if ((x <= -1.0) || !(x <= 1.0)) {
tmp = -2.0 / (x * x);
} else {
tmp = 2.0;
}
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 = (-2.0d0) / (x * x)
else
tmp = 2.0d0
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if ((x <= -1.0) || !(x <= 1.0)) {
tmp = -2.0 / (x * x);
} else {
tmp = 2.0;
}
return tmp;
}
def code(x): tmp = 0 if (x <= -1.0) or not (x <= 1.0): tmp = -2.0 / (x * x) else: tmp = 2.0 return tmp
function code(x) tmp = 0.0 if ((x <= -1.0) || !(x <= 1.0)) tmp = Float64(-2.0 / Float64(x * x)); else tmp = 2.0; end return tmp end
function tmp_2 = code(x) tmp = 0.0; if ((x <= -1.0) || ~((x <= 1.0))) tmp = -2.0 / (x * x); else tmp = 2.0; end tmp_2 = tmp; end
code[x_] := If[Or[LessEqual[x, -1.0], N[Not[LessEqual[x, 1.0]], $MachinePrecision]], N[(-2.0 / N[(x * x), $MachinePrecision]), $MachinePrecision], 2.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\
\;\;\;\;\frac{-2}{x \cdot x}\\
\mathbf{else}:\\
\;\;\;\;2\\
\end{array}
\end{array}
if x < -1 or 1 < x Initial program 54.5%
Taylor expanded in x around inf 96.5%
unpow296.5%
Simplified96.5%
if -1 < x < 1Initial program 100.0%
Taylor expanded in x around 0 99.9%
Final simplification98.1%
(FPCore (x) :precision binary64 (if (or (<= x -1.0) (not (<= x 1.0))) (/ (/ -2.0 x) x) 2.0))
double code(double x) {
double tmp;
if ((x <= -1.0) || !(x <= 1.0)) {
tmp = (-2.0 / x) / x;
} else {
tmp = 2.0;
}
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 = ((-2.0d0) / x) / x
else
tmp = 2.0d0
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if ((x <= -1.0) || !(x <= 1.0)) {
tmp = (-2.0 / x) / x;
} else {
tmp = 2.0;
}
return tmp;
}
def code(x): tmp = 0 if (x <= -1.0) or not (x <= 1.0): tmp = (-2.0 / x) / x else: tmp = 2.0 return tmp
function code(x) tmp = 0.0 if ((x <= -1.0) || !(x <= 1.0)) tmp = Float64(Float64(-2.0 / x) / x); else tmp = 2.0; end return tmp end
function tmp_2 = code(x) tmp = 0.0; if ((x <= -1.0) || ~((x <= 1.0))) tmp = (-2.0 / x) / x; else tmp = 2.0; end tmp_2 = tmp; end
code[x_] := If[Or[LessEqual[x, -1.0], N[Not[LessEqual[x, 1.0]], $MachinePrecision]], N[(N[(-2.0 / x), $MachinePrecision] / x), $MachinePrecision], 2.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1 \lor \neg \left(x \leq 1\right):\\
\;\;\;\;\frac{\frac{-2}{x}}{x}\\
\mathbf{else}:\\
\;\;\;\;2\\
\end{array}
\end{array}
if x < -1 or 1 < x Initial program 54.5%
frac-sub56.2%
associate-/r*56.2%
*-un-lft-identity56.2%
*-rgt-identity56.2%
associate--l-56.2%
+-commutative56.2%
+-commutative56.2%
sub-neg56.2%
metadata-eval56.2%
Applied egg-rr56.2%
Taylor expanded in x around 0 99.8%
Taylor expanded in x around inf 96.5%
unpow296.5%
associate-/r*98.3%
Simplified98.3%
if -1 < x < 1Initial program 100.0%
Taylor expanded in x around 0 99.9%
Final simplification99.1%
(FPCore (x) :precision binary64 (/ 2.0 (- 1.0 (* x x))))
double code(double x) {
return 2.0 / (1.0 - (x * x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 2.0d0 / (1.0d0 - (x * x))
end function
public static double code(double x) {
return 2.0 / (1.0 - (x * x));
}
def code(x): return 2.0 / (1.0 - (x * x))
function code(x) return Float64(2.0 / Float64(1.0 - Float64(x * x))) end
function tmp = code(x) tmp = 2.0 / (1.0 - (x * x)); end
code[x_] := N[(2.0 / N[(1.0 - N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{2}{1 - x \cdot x}
\end{array}
Initial program 76.4%
frac-2neg76.4%
metadata-eval76.4%
frac-sub77.2%
*-un-lft-identity77.2%
sub-neg77.2%
metadata-eval77.2%
distribute-neg-in77.2%
metadata-eval77.2%
+-commutative77.2%
+-commutative77.2%
sub-neg77.2%
metadata-eval77.2%
distribute-neg-in77.2%
metadata-eval77.2%
Applied egg-rr77.2%
Taylor expanded in x around 0 98.9%
Taylor expanded in x around 0 98.9%
unpow298.9%
mul-1-neg98.9%
unsub-neg98.9%
Simplified98.9%
Final simplification98.9%
(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 76.4%
Taylor expanded in x around 0 49.4%
Final simplification49.4%
herbie shell --seed 2023181
(FPCore (x)
:name "Asymptote A"
:precision binary64
(- (/ 1.0 (+ x 1.0)) (/ 1.0 (- x 1.0))))