
(FPCore (x) :precision binary64 (+ (/ 1.0 (- x 1.0)) (/ x (+ x 1.0))))
double code(double x) {
return (1.0 / (x - 1.0)) + (x / (x + 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / (x - 1.0d0)) + (x / (x + 1.0d0))
end function
public static double code(double x) {
return (1.0 / (x - 1.0)) + (x / (x + 1.0));
}
def code(x): return (1.0 / (x - 1.0)) + (x / (x + 1.0))
function code(x) return Float64(Float64(1.0 / Float64(x - 1.0)) + Float64(x / Float64(x + 1.0))) end
function tmp = code(x) tmp = (1.0 / (x - 1.0)) + (x / (x + 1.0)); end
code[x_] := N[(N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision] + N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x - 1} + \frac{x}{x + 1}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (+ (/ 1.0 (- x 1.0)) (/ x (+ x 1.0))))
double code(double x) {
return (1.0 / (x - 1.0)) + (x / (x + 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / (x - 1.0d0)) + (x / (x + 1.0d0))
end function
public static double code(double x) {
return (1.0 / (x - 1.0)) + (x / (x + 1.0));
}
def code(x): return (1.0 / (x - 1.0)) + (x / (x + 1.0))
function code(x) return Float64(Float64(1.0 / Float64(x - 1.0)) + Float64(x / Float64(x + 1.0))) end
function tmp = code(x) tmp = (1.0 / (x - 1.0)) + (x / (x + 1.0)); end
code[x_] := N[(N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision] + N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x - 1} + \frac{x}{x + 1}
\end{array}
(FPCore (x) :precision binary64 (/ (- (/ (- -1.0 x) (+ -1.0 x)) x) (- -1.0 x)))
double code(double x) {
return (((-1.0 - x) / (-1.0 + x)) - x) / (-1.0 - x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = ((((-1.0d0) - x) / ((-1.0d0) + x)) - x) / ((-1.0d0) - x)
end function
public static double code(double x) {
return (((-1.0 - x) / (-1.0 + x)) - x) / (-1.0 - x);
}
def code(x): return (((-1.0 - x) / (-1.0 + x)) - x) / (-1.0 - x)
function code(x) return Float64(Float64(Float64(Float64(-1.0 - x) / Float64(-1.0 + x)) - x) / Float64(-1.0 - x)) end
function tmp = code(x) tmp = (((-1.0 - x) / (-1.0 + x)) - x) / (-1.0 - x); end
code[x_] := N[(N[(N[(N[(-1.0 - x), $MachinePrecision] / N[(-1.0 + x), $MachinePrecision]), $MachinePrecision] - x), $MachinePrecision] / N[(-1.0 - x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{-1 - x}{-1 + x} - x}{-1 - x}
\end{array}
Initial program 100.0%
remove-double-neg100.0%
distribute-frac-neg100.0%
unsub-neg100.0%
sub-neg100.0%
metadata-eval100.0%
neg-mul-1100.0%
metadata-eval100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
associate-*l/100.0%
/-rgt-identity100.0%
distribute-rgt1-in100.0%
*-commutative100.0%
metadata-eval100.0%
neg-mul-1100.0%
unsub-neg100.0%
metadata-eval100.0%
Simplified100.0%
frac-sub71.1%
associate-/r*72.0%
*-un-lft-identity72.0%
*-commutative72.0%
Applied egg-rr72.0%
div-sub72.0%
sub-neg72.0%
+-commutative72.0%
associate-/l*100.0%
+-commutative100.0%
+-commutative100.0%
Applied egg-rr100.0%
sub-neg100.0%
+-commutative100.0%
*-inverses100.0%
/-rgt-identity100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (x) :precision binary64 (+ (/ 1.0 (+ -1.0 x)) (/ x (+ x 1.0))))
double code(double x) {
return (1.0 / (-1.0 + x)) + (x / (x + 1.0));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / ((-1.0d0) + x)) + (x / (x + 1.0d0))
end function
public static double code(double x) {
return (1.0 / (-1.0 + x)) + (x / (x + 1.0));
}
def code(x): return (1.0 / (-1.0 + x)) + (x / (x + 1.0))
function code(x) return Float64(Float64(1.0 / Float64(-1.0 + x)) + Float64(x / Float64(x + 1.0))) end
function tmp = code(x) tmp = (1.0 / (-1.0 + x)) + (x / (x + 1.0)); end
code[x_] := N[(N[(1.0 / N[(-1.0 + x), $MachinePrecision]), $MachinePrecision] + N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{-1 + x} + \frac{x}{x + 1}
\end{array}
Initial program 100.0%
Final simplification100.0%
(FPCore (x) :precision binary64 (if (<= x -1.0) 1.0 (if (<= x 1.0) -1.0 1.0)))
double code(double x) {
double tmp;
if (x <= -1.0) {
tmp = 1.0;
} else if (x <= 1.0) {
tmp = -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (x <= (-1.0d0)) then
tmp = 1.0d0
else if (x <= 1.0d0) then
tmp = -1.0d0
else
tmp = 1.0d0
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (x <= -1.0) {
tmp = 1.0;
} else if (x <= 1.0) {
tmp = -1.0;
} else {
tmp = 1.0;
}
return tmp;
}
def code(x): tmp = 0 if x <= -1.0: tmp = 1.0 elif x <= 1.0: tmp = -1.0 else: tmp = 1.0 return tmp
function code(x) tmp = 0.0 if (x <= -1.0) tmp = 1.0; elseif (x <= 1.0) tmp = -1.0; else tmp = 1.0; end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (x <= -1.0) tmp = 1.0; elseif (x <= 1.0) tmp = -1.0; else tmp = 1.0; end tmp_2 = tmp; end
code[x_] := If[LessEqual[x, -1.0], 1.0, If[LessEqual[x, 1.0], -1.0, 1.0]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;x \leq -1:\\
\;\;\;\;1\\
\mathbf{elif}\;x \leq 1:\\
\;\;\;\;-1\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if x < -1 or 1 < x Initial program 100.0%
remove-double-neg100.0%
distribute-frac-neg100.0%
unsub-neg100.0%
sub-neg100.0%
metadata-eval100.0%
neg-mul-1100.0%
metadata-eval100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
associate-*l/100.0%
/-rgt-identity100.0%
distribute-rgt1-in100.0%
*-commutative100.0%
metadata-eval100.0%
neg-mul-1100.0%
unsub-neg100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in x around inf 99.3%
if -1 < x < 1Initial program 100.0%
remove-double-neg100.0%
distribute-frac-neg100.0%
unsub-neg100.0%
sub-neg100.0%
metadata-eval100.0%
neg-mul-1100.0%
metadata-eval100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
associate-*l/100.0%
/-rgt-identity100.0%
distribute-rgt1-in100.0%
*-commutative100.0%
metadata-eval100.0%
neg-mul-1100.0%
unsub-neg100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in x around 0 100.0%
Final simplification99.6%
(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 100.0%
remove-double-neg100.0%
distribute-frac-neg100.0%
unsub-neg100.0%
sub-neg100.0%
metadata-eval100.0%
neg-mul-1100.0%
metadata-eval100.0%
*-commutative100.0%
associate-/l*100.0%
metadata-eval100.0%
metadata-eval100.0%
metadata-eval100.0%
associate-/l*100.0%
associate-*l/100.0%
/-rgt-identity100.0%
distribute-rgt1-in100.0%
*-commutative100.0%
metadata-eval100.0%
neg-mul-1100.0%
unsub-neg100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in x around 0 49.6%
Final simplification49.6%
herbie shell --seed 2023326
(FPCore (x)
:name "Asymptote B"
:precision binary64
(+ (/ 1.0 (- x 1.0)) (/ x (+ x 1.0))))