
(FPCore (x) :precision binary64 (log (+ (/ 1.0 x) (/ (sqrt (- 1.0 (* x x))) x))))
double code(double x) {
return log(((1.0 / x) + (sqrt((1.0 - (x * x))) / x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = log(((1.0d0 / x) + (sqrt((1.0d0 - (x * x))) / x)))
end function
public static double code(double x) {
return Math.log(((1.0 / x) + (Math.sqrt((1.0 - (x * x))) / x)));
}
def code(x): return math.log(((1.0 / x) + (math.sqrt((1.0 - (x * x))) / x)))
function code(x) return log(Float64(Float64(1.0 / x) + Float64(sqrt(Float64(1.0 - Float64(x * x))) / x))) end
function tmp = code(x) tmp = log(((1.0 / x) + (sqrt((1.0 - (x * x))) / x))); end
code[x_] := N[Log[N[(N[(1.0 / x), $MachinePrecision] + N[(N[Sqrt[N[(1.0 - N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\frac{1}{x} + \frac{\sqrt{1 - x \cdot x}}{x}\right)
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (log (+ (/ 1.0 x) (/ (sqrt (- 1.0 (* x x))) x))))
double code(double x) {
return log(((1.0 / x) + (sqrt((1.0 - (x * x))) / x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = log(((1.0d0 / x) + (sqrt((1.0d0 - (x * x))) / x)))
end function
public static double code(double x) {
return Math.log(((1.0 / x) + (Math.sqrt((1.0 - (x * x))) / x)));
}
def code(x): return math.log(((1.0 / x) + (math.sqrt((1.0 - (x * x))) / x)))
function code(x) return log(Float64(Float64(1.0 / x) + Float64(sqrt(Float64(1.0 - Float64(x * x))) / x))) end
function tmp = code(x) tmp = log(((1.0 / x) + (sqrt((1.0 - (x * x))) / x))); end
code[x_] := N[Log[N[(N[(1.0 / x), $MachinePrecision] + N[(N[Sqrt[N[(1.0 - N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\frac{1}{x} + \frac{\sqrt{1 - x \cdot x}}{x}\right)
\end{array}
(FPCore (x) :precision binary64 (log1p (+ (/ (+ 1.0 (sqrt (- 1.0 (* x x)))) x) -1.0)))
double code(double x) {
return log1p((((1.0 + sqrt((1.0 - (x * x)))) / x) + -1.0));
}
public static double code(double x) {
return Math.log1p((((1.0 + Math.sqrt((1.0 - (x * x)))) / x) + -1.0));
}
def code(x): return math.log1p((((1.0 + math.sqrt((1.0 - (x * x)))) / x) + -1.0))
function code(x) return log1p(Float64(Float64(Float64(1.0 + sqrt(Float64(1.0 - Float64(x * x)))) / x) + -1.0)) end
code[x_] := N[Log[1 + N[(N[(N[(1.0 + N[Sqrt[N[(1.0 - N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision] + -1.0), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\mathsf{log1p}\left(\frac{1 + \sqrt{1 - x \cdot x}}{x} + -1\right)
\end{array}
Initial program 100.0%
+-commutative100.0%
--rgt-identity100.0%
associate--r-100.0%
sqr-neg100.0%
neg-sub0100.0%
distribute-neg-frac100.0%
metadata-eval100.0%
div-sub100.0%
*-lft-identity100.0%
associate-*l/100.0%
sub-neg100.0%
sqr-neg100.0%
metadata-eval100.0%
Simplified100.0%
log1p-expm1-u100.0%
expm1-undefine100.0%
add-exp-log100.0%
associate-*l/100.0%
*-un-lft-identity100.0%
+-commutative100.0%
pow2100.0%
Applied egg-rr100.0%
unpow2100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (x) :precision binary64 (log (* (+ 1.0 (sqrt (- 1.0 (* x x)))) (/ 1.0 x))))
double code(double x) {
return log(((1.0 + sqrt((1.0 - (x * x)))) * (1.0 / x)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = log(((1.0d0 + sqrt((1.0d0 - (x * x)))) * (1.0d0 / x)))
end function
public static double code(double x) {
return Math.log(((1.0 + Math.sqrt((1.0 - (x * x)))) * (1.0 / x)));
}
def code(x): return math.log(((1.0 + math.sqrt((1.0 - (x * x)))) * (1.0 / x)))
function code(x) return log(Float64(Float64(1.0 + sqrt(Float64(1.0 - Float64(x * x)))) * Float64(1.0 / x))) end
function tmp = code(x) tmp = log(((1.0 + sqrt((1.0 - (x * x)))) * (1.0 / x))); end
code[x_] := N[Log[N[(N[(1.0 + N[Sqrt[N[(1.0 - N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * N[(1.0 / x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\left(1 + \sqrt{1 - x \cdot x}\right) \cdot \frac{1}{x}\right)
\end{array}
Initial program 100.0%
+-commutative100.0%
--rgt-identity100.0%
associate--r-100.0%
sqr-neg100.0%
neg-sub0100.0%
distribute-neg-frac100.0%
metadata-eval100.0%
div-sub100.0%
*-lft-identity100.0%
associate-*l/100.0%
sub-neg100.0%
sqr-neg100.0%
metadata-eval100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (x) :precision binary64 (log (/ (+ 2.0 (* (* x x) -0.5)) x)))
double code(double x) {
return log(((2.0 + ((x * x) * -0.5)) / x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = log(((2.0d0 + ((x * x) * (-0.5d0))) / x))
end function
public static double code(double x) {
return Math.log(((2.0 + ((x * x) * -0.5)) / x));
}
def code(x): return math.log(((2.0 + ((x * x) * -0.5)) / x))
function code(x) return log(Float64(Float64(2.0 + Float64(Float64(x * x) * -0.5)) / x)) end
function tmp = code(x) tmp = log(((2.0 + ((x * x) * -0.5)) / x)); end
code[x_] := N[Log[N[(N[(2.0 + N[(N[(x * x), $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\frac{2 + \left(x \cdot x\right) \cdot -0.5}{x}\right)
\end{array}
Initial program 100.0%
+-commutative100.0%
--rgt-identity100.0%
associate--r-100.0%
sqr-neg100.0%
neg-sub0100.0%
distribute-neg-frac100.0%
metadata-eval100.0%
div-sub100.0%
*-lft-identity100.0%
associate-*l/100.0%
sub-neg100.0%
sqr-neg100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in x around 0 99.4%
unpow2100.0%
Applied egg-rr99.4%
Final simplification99.4%
(FPCore (x) :precision binary64 (log (/ 2.0 x)))
double code(double x) {
return log((2.0 / x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = log((2.0d0 / x))
end function
public static double code(double x) {
return Math.log((2.0 / x));
}
def code(x): return math.log((2.0 / x))
function code(x) return log(Float64(2.0 / x)) end
function tmp = code(x) tmp = log((2.0 / x)); end
code[x_] := N[Log[N[(2.0 / x), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\frac{2}{x}\right)
\end{array}
Initial program 100.0%
+-commutative100.0%
--rgt-identity100.0%
associate--r-100.0%
sqr-neg100.0%
neg-sub0100.0%
distribute-neg-frac100.0%
metadata-eval100.0%
div-sub100.0%
*-lft-identity100.0%
associate-*l/100.0%
sub-neg100.0%
sqr-neg100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in x around 0 98.9%
(FPCore (x) :precision binary64 (- (log1p -1.0)))
double code(double x) {
return -log1p(-1.0);
}
public static double code(double x) {
return -Math.log1p(-1.0);
}
def code(x): return -math.log1p(-1.0)
function code(x) return Float64(-log1p(-1.0)) end
code[x_] := (-N[Log[1 + -1.0], $MachinePrecision])
\begin{array}{l}
\\
-\mathsf{log1p}\left(-1\right)
\end{array}
Initial program 100.0%
+-commutative100.0%
--rgt-identity100.0%
associate--r-100.0%
sqr-neg100.0%
neg-sub0100.0%
distribute-neg-frac100.0%
metadata-eval100.0%
div-sub100.0%
*-lft-identity100.0%
associate-*l/100.0%
sub-neg100.0%
sqr-neg100.0%
metadata-eval100.0%
Simplified100.0%
Taylor expanded in x around 0 98.9%
clear-num98.9%
log-rec98.9%
div-inv98.9%
metadata-eval98.9%
Applied egg-rr98.9%
log1p-expm1-u5.6%
expm1-undefine5.6%
add-exp-log5.6%
Applied egg-rr5.6%
Taylor expanded in x around 0 3.1%
herbie shell --seed 2024112
(FPCore (x)
:name "Hyperbolic arc-(co)secant"
:precision binary64
(log (+ (/ 1.0 x) (/ (sqrt (- 1.0 (* x x))) x))))