
(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 4 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 (pow x 2.0)))) x) -1.0)))
double code(double x) {
return log1p((((1.0 + sqrt((1.0 - pow(x, 2.0)))) / x) + -1.0));
}
public static double code(double x) {
return Math.log1p((((1.0 + Math.sqrt((1.0 - Math.pow(x, 2.0)))) / x) + -1.0));
}
def code(x): return math.log1p((((1.0 + math.sqrt((1.0 - math.pow(x, 2.0)))) / x) + -1.0))
function code(x) return log1p(Float64(Float64(Float64(1.0 + sqrt(Float64(1.0 - (x ^ 2.0)))) / x) + -1.0)) end
code[x_] := N[Log[1 + N[(N[(N[(1.0 + N[Sqrt[N[(1.0 - N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision] + -1.0), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\mathsf{log1p}\left(\frac{1 + \sqrt{1 - {x}^{2}}}{x} + -1\right)
\end{array}
Initial program 100.0%
sqr-neg100.0%
remove-double-neg100.0%
distribute-frac-neg2100.0%
sub-neg100.0%
neg-mul-1100.0%
associate-/r*100.0%
div-sub100.0%
*-lft-identity100.0%
associate-*l/100.0%
sub-neg100.0%
distribute-neg-frac2100.0%
metadata-eval100.0%
/-rgt-identity100.0%
Simplified100.0%
log1p-expm1-u100.0%
expm1-undefine100.0%
add-exp-log100.0%
associate-*l/100.0%
*-un-lft-identity100.0%
pow2100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (x) :precision binary64 (log (* (/ 1.0 x) (+ 1.0 (sqrt (- 1.0 (* x x)))))))
double code(double x) {
return log(((1.0 / x) * (1.0 + sqrt((1.0 - (x * x))))));
}
real(8) function code(x)
real(8), intent (in) :: x
code = log(((1.0d0 / x) * (1.0d0 + sqrt((1.0d0 - (x * x))))))
end function
public static double code(double x) {
return Math.log(((1.0 / x) * (1.0 + Math.sqrt((1.0 - (x * x))))));
}
def code(x): return math.log(((1.0 / x) * (1.0 + math.sqrt((1.0 - (x * x))))))
function code(x) return log(Float64(Float64(1.0 / x) * Float64(1.0 + sqrt(Float64(1.0 - Float64(x * x)))))) end
function tmp = code(x) tmp = log(((1.0 / x) * (1.0 + sqrt((1.0 - (x * x)))))); end
code[x_] := N[Log[N[(N[(1.0 / x), $MachinePrecision] * N[(1.0 + N[Sqrt[N[(1.0 - N[(x * x), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\frac{1}{x} \cdot \left(1 + \sqrt{1 - x \cdot x}\right)\right)
\end{array}
Initial program 100.0%
sqr-neg100.0%
remove-double-neg100.0%
distribute-frac-neg2100.0%
sub-neg100.0%
neg-mul-1100.0%
associate-/r*100.0%
div-sub100.0%
*-lft-identity100.0%
associate-*l/100.0%
sub-neg100.0%
distribute-neg-frac2100.0%
metadata-eval100.0%
/-rgt-identity100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (x) :precision binary64 (log (/ (+ 2.0 (* (pow x 2.0) -0.5)) x)))
double code(double x) {
return log(((2.0 + (pow(x, 2.0) * -0.5)) / x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = log(((2.0d0 + ((x ** 2.0d0) * (-0.5d0))) / x))
end function
public static double code(double x) {
return Math.log(((2.0 + (Math.pow(x, 2.0) * -0.5)) / x));
}
def code(x): return math.log(((2.0 + (math.pow(x, 2.0) * -0.5)) / x))
function code(x) return log(Float64(Float64(2.0 + Float64((x ^ 2.0) * -0.5)) / x)) end
function tmp = code(x) tmp = log(((2.0 + ((x ^ 2.0) * -0.5)) / x)); end
code[x_] := N[Log[N[(N[(2.0 + N[(N[Power[x, 2.0], $MachinePrecision] * -0.5), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\log \left(\frac{2 + {x}^{2} \cdot -0.5}{x}\right)
\end{array}
Initial program 100.0%
sqr-neg100.0%
remove-double-neg100.0%
distribute-frac-neg2100.0%
sub-neg100.0%
neg-mul-1100.0%
associate-/r*100.0%
div-sub100.0%
*-lft-identity100.0%
associate-*l/100.0%
sub-neg100.0%
distribute-neg-frac2100.0%
metadata-eval100.0%
/-rgt-identity100.0%
Simplified100.0%
Taylor expanded in x around 0 99.4%
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%
sqr-neg100.0%
remove-double-neg100.0%
distribute-frac-neg2100.0%
sub-neg100.0%
neg-mul-1100.0%
associate-/r*100.0%
div-sub100.0%
*-lft-identity100.0%
associate-*l/100.0%
sub-neg100.0%
distribute-neg-frac2100.0%
metadata-eval100.0%
/-rgt-identity100.0%
Simplified100.0%
Taylor expanded in x around 0 98.9%
Final simplification98.9%
herbie shell --seed 2024112
(FPCore (x)
:name "Hyperbolic arc-(co)secant"
:precision binary64
(log (+ (/ 1.0 x) (/ (sqrt (- 1.0 (* x x))) x))))