
(FPCore (u1 u2) :precision binary64 (+ (* (* (/ 1.0 6.0) (pow (* -2.0 (log u1)) 0.5)) (cos (* (* 2.0 PI) u2))) 0.5))
double code(double u1, double u2) {
return (((1.0 / 6.0) * pow((-2.0 * log(u1)), 0.5)) * cos(((2.0 * ((double) M_PI)) * u2))) + 0.5;
}
public static double code(double u1, double u2) {
return (((1.0 / 6.0) * Math.pow((-2.0 * Math.log(u1)), 0.5)) * Math.cos(((2.0 * Math.PI) * u2))) + 0.5;
}
def code(u1, u2): return (((1.0 / 6.0) * math.pow((-2.0 * math.log(u1)), 0.5)) * math.cos(((2.0 * math.pi) * u2))) + 0.5
function code(u1, u2) return Float64(Float64(Float64(Float64(1.0 / 6.0) * (Float64(-2.0 * log(u1)) ^ 0.5)) * cos(Float64(Float64(2.0 * pi) * u2))) + 0.5) end
function tmp = code(u1, u2) tmp = (((1.0 / 6.0) * ((-2.0 * log(u1)) ^ 0.5)) * cos(((2.0 * pi) * u2))) + 0.5; end
code[u1_, u2_] := N[(N[(N[(N[(1.0 / 6.0), $MachinePrecision] * N[Power[N[(-2.0 * N[Log[u1], $MachinePrecision]), $MachinePrecision], 0.5], $MachinePrecision]), $MachinePrecision] * N[Cos[N[(N[(2.0 * Pi), $MachinePrecision] * u2), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\left(\frac{1}{6} \cdot {\left(-2 \cdot \log u1\right)}^{0.5}\right) \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right) + 0.5
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (u1 u2) :precision binary64 (+ (* (* (/ 1.0 6.0) (pow (* -2.0 (log u1)) 0.5)) (cos (* (* 2.0 PI) u2))) 0.5))
double code(double u1, double u2) {
return (((1.0 / 6.0) * pow((-2.0 * log(u1)), 0.5)) * cos(((2.0 * ((double) M_PI)) * u2))) + 0.5;
}
public static double code(double u1, double u2) {
return (((1.0 / 6.0) * Math.pow((-2.0 * Math.log(u1)), 0.5)) * Math.cos(((2.0 * Math.PI) * u2))) + 0.5;
}
def code(u1, u2): return (((1.0 / 6.0) * math.pow((-2.0 * math.log(u1)), 0.5)) * math.cos(((2.0 * math.pi) * u2))) + 0.5
function code(u1, u2) return Float64(Float64(Float64(Float64(1.0 / 6.0) * (Float64(-2.0 * log(u1)) ^ 0.5)) * cos(Float64(Float64(2.0 * pi) * u2))) + 0.5) end
function tmp = code(u1, u2) tmp = (((1.0 / 6.0) * ((-2.0 * log(u1)) ^ 0.5)) * cos(((2.0 * pi) * u2))) + 0.5; end
code[u1_, u2_] := N[(N[(N[(N[(1.0 / 6.0), $MachinePrecision] * N[Power[N[(-2.0 * N[Log[u1], $MachinePrecision]), $MachinePrecision], 0.5], $MachinePrecision]), $MachinePrecision] * N[Cos[N[(N[(2.0 * Pi), $MachinePrecision] * u2), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\left(\frac{1}{6} \cdot {\left(-2 \cdot \log u1\right)}^{0.5}\right) \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right) + 0.5
\end{array}
(FPCore (u1 u2) :precision binary64 (+ (* (* (* 0.16666666666666666 (sqrt 2.0)) (sqrt (- (log u1)))) (cos (* (* 2.0 PI) u2))) 0.5))
double code(double u1, double u2) {
return (((0.16666666666666666 * sqrt(2.0)) * sqrt(-log(u1))) * cos(((2.0 * ((double) M_PI)) * u2))) + 0.5;
}
public static double code(double u1, double u2) {
return (((0.16666666666666666 * Math.sqrt(2.0)) * Math.sqrt(-Math.log(u1))) * Math.cos(((2.0 * Math.PI) * u2))) + 0.5;
}
def code(u1, u2): return (((0.16666666666666666 * math.sqrt(2.0)) * math.sqrt(-math.log(u1))) * math.cos(((2.0 * math.pi) * u2))) + 0.5
function code(u1, u2) return Float64(Float64(Float64(Float64(0.16666666666666666 * sqrt(2.0)) * sqrt(Float64(-log(u1)))) * cos(Float64(Float64(2.0 * pi) * u2))) + 0.5) end
function tmp = code(u1, u2) tmp = (((0.16666666666666666 * sqrt(2.0)) * sqrt(-log(u1))) * cos(((2.0 * pi) * u2))) + 0.5; end
code[u1_, u2_] := N[(N[(N[(N[(0.16666666666666666 * N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision] * N[Sqrt[(-N[Log[u1], $MachinePrecision])], $MachinePrecision]), $MachinePrecision] * N[Cos[N[(N[(2.0 * Pi), $MachinePrecision] * u2), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]
\begin{array}{l}
\\
\left(\left(0.16666666666666666 \cdot \sqrt{2}\right) \cdot \sqrt{-\log u1}\right) \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right) + 0.5
\end{array}
Initial program 99.4%
Taylor expanded in u1 around inf 99.5%
associate-*r*99.6%
log-rec99.6%
Simplified99.6%
Final simplification99.6%
(FPCore (u1 u2) :precision binary64 (+ 0.5 (* (cos (* (* 2.0 PI) u2)) (sqrt (* (log u1) -0.05555555555555555)))))
double code(double u1, double u2) {
return 0.5 + (cos(((2.0 * ((double) M_PI)) * u2)) * sqrt((log(u1) * -0.05555555555555555)));
}
public static double code(double u1, double u2) {
return 0.5 + (Math.cos(((2.0 * Math.PI) * u2)) * Math.sqrt((Math.log(u1) * -0.05555555555555555)));
}
def code(u1, u2): return 0.5 + (math.cos(((2.0 * math.pi) * u2)) * math.sqrt((math.log(u1) * -0.05555555555555555)))
function code(u1, u2) return Float64(0.5 + Float64(cos(Float64(Float64(2.0 * pi) * u2)) * sqrt(Float64(log(u1) * -0.05555555555555555)))) end
function tmp = code(u1, u2) tmp = 0.5 + (cos(((2.0 * pi) * u2)) * sqrt((log(u1) * -0.05555555555555555))); end
code[u1_, u2_] := N[(0.5 + N[(N[Cos[N[(N[(2.0 * Pi), $MachinePrecision] * u2), $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[(N[Log[u1], $MachinePrecision] * -0.05555555555555555), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 + \cos \left(\left(2 \cdot \pi\right) \cdot u2\right) \cdot \sqrt{\log u1 \cdot -0.05555555555555555}
\end{array}
Initial program 99.4%
add-sqr-sqrt99.0%
sqrt-unprod99.4%
pow1/299.4%
*-commutative99.4%
pow1/299.4%
*-commutative99.4%
swap-sqr99.4%
add-sqr-sqrt99.6%
metadata-eval99.6%
metadata-eval99.6%
metadata-eval99.6%
Applied egg-rr99.6%
*-commutative99.6%
associate-*l*99.6%
metadata-eval99.6%
Simplified99.6%
Final simplification99.6%
(FPCore (u1 u2) :precision binary64 (+ 0.5 (* (sqrt (- (log u1))) (* 0.16666666666666666 (pow 4.0 0.25)))))
double code(double u1, double u2) {
return 0.5 + (sqrt(-log(u1)) * (0.16666666666666666 * pow(4.0, 0.25)));
}
real(8) function code(u1, u2)
real(8), intent (in) :: u1
real(8), intent (in) :: u2
code = 0.5d0 + (sqrt(-log(u1)) * (0.16666666666666666d0 * (4.0d0 ** 0.25d0)))
end function
public static double code(double u1, double u2) {
return 0.5 + (Math.sqrt(-Math.log(u1)) * (0.16666666666666666 * Math.pow(4.0, 0.25)));
}
def code(u1, u2): return 0.5 + (math.sqrt(-math.log(u1)) * (0.16666666666666666 * math.pow(4.0, 0.25)))
function code(u1, u2) return Float64(0.5 + Float64(sqrt(Float64(-log(u1))) * Float64(0.16666666666666666 * (4.0 ^ 0.25)))) end
function tmp = code(u1, u2) tmp = 0.5 + (sqrt(-log(u1)) * (0.16666666666666666 * (4.0 ^ 0.25))); end
code[u1_, u2_] := N[(0.5 + N[(N[Sqrt[(-N[Log[u1], $MachinePrecision])], $MachinePrecision] * N[(0.16666666666666666 * N[Power[4.0, 0.25], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 + \sqrt{-\log u1} \cdot \left(0.16666666666666666 \cdot {4}^{0.25}\right)
\end{array}
Initial program 99.4%
*-commutative99.4%
associate-*l*99.5%
fma-def99.5%
unpow1/299.5%
metadata-eval99.5%
associate-*l*99.5%
Simplified99.5%
Taylor expanded in u2 around 0 97.7%
pow1/297.7%
metadata-eval97.7%
metadata-eval97.7%
pow-sqr97.4%
pow-prod-down97.7%
swap-sqr97.7%
metadata-eval97.7%
pow297.7%
metadata-eval97.7%
Applied egg-rr97.7%
Taylor expanded in u1 around inf 97.8%
associate-*r*97.9%
log-rec97.9%
Simplified97.9%
Final simplification97.9%
(FPCore (u1 u2) :precision binary64 (+ 0.5 (* 0.16666666666666666 (sqrt (* (log u1) -2.0)))))
double code(double u1, double u2) {
return 0.5 + (0.16666666666666666 * sqrt((log(u1) * -2.0)));
}
real(8) function code(u1, u2)
real(8), intent (in) :: u1
real(8), intent (in) :: u2
code = 0.5d0 + (0.16666666666666666d0 * sqrt((log(u1) * (-2.0d0))))
end function
public static double code(double u1, double u2) {
return 0.5 + (0.16666666666666666 * Math.sqrt((Math.log(u1) * -2.0)));
}
def code(u1, u2): return 0.5 + (0.16666666666666666 * math.sqrt((math.log(u1) * -2.0)))
function code(u1, u2) return Float64(0.5 + Float64(0.16666666666666666 * sqrt(Float64(log(u1) * -2.0)))) end
function tmp = code(u1, u2) tmp = 0.5 + (0.16666666666666666 * sqrt((log(u1) * -2.0))); end
code[u1_, u2_] := N[(0.5 + N[(0.16666666666666666 * N[Sqrt[N[(N[Log[u1], $MachinePrecision] * -2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 + 0.16666666666666666 \cdot \sqrt{\log u1 \cdot -2}
\end{array}
Initial program 99.4%
*-commutative99.4%
associate-*l*99.5%
fma-def99.5%
unpow1/299.5%
metadata-eval99.5%
associate-*l*99.5%
Simplified99.5%
Taylor expanded in u2 around 0 97.7%
pow1/297.7%
metadata-eval97.7%
metadata-eval97.7%
pow-sqr97.4%
pow-prod-down97.7%
swap-sqr97.7%
metadata-eval97.7%
pow297.7%
metadata-eval97.7%
Applied egg-rr97.7%
add-sqr-sqrt97.3%
sqrt-unprod97.7%
pow-sqr97.7%
metadata-eval97.7%
pow1/297.7%
*-commutative97.7%
unpow297.7%
metadata-eval97.7%
swap-sqr97.7%
sqrt-unprod97.7%
add-sqr-sqrt97.7%
*-commutative97.7%
fma-def97.7%
*-commutative97.7%
*-commutative97.7%
Applied egg-rr97.7%
Final simplification97.7%
(FPCore (u1 u2) :precision binary64 (+ 0.5 (sqrt (* (log u1) 0.05555555555555555))))
double code(double u1, double u2) {
return 0.5 + sqrt((log(u1) * 0.05555555555555555));
}
real(8) function code(u1, u2)
real(8), intent (in) :: u1
real(8), intent (in) :: u2
code = 0.5d0 + sqrt((log(u1) * 0.05555555555555555d0))
end function
public static double code(double u1, double u2) {
return 0.5 + Math.sqrt((Math.log(u1) * 0.05555555555555555));
}
def code(u1, u2): return 0.5 + math.sqrt((math.log(u1) * 0.05555555555555555))
function code(u1, u2) return Float64(0.5 + sqrt(Float64(log(u1) * 0.05555555555555555))) end
function tmp = code(u1, u2) tmp = 0.5 + sqrt((log(u1) * 0.05555555555555555)); end
code[u1_, u2_] := N[(0.5 + N[Sqrt[N[(N[Log[u1], $MachinePrecision] * 0.05555555555555555), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 + \sqrt{\log u1 \cdot 0.05555555555555555}
\end{array}
Initial program 99.4%
*-commutative99.4%
associate-*l*99.5%
fma-def99.5%
unpow1/299.5%
metadata-eval99.5%
associate-*l*99.5%
Simplified99.5%
Taylor expanded in u2 around 0 97.7%
fma-udef97.7%
*-commutative97.7%
Applied egg-rr0.0%
Final simplification0.0%
herbie shell --seed 2023207
(FPCore (u1 u2)
:name "normal distribution"
:precision binary64
:pre (and (and (<= 0.0 u1) (<= u1 1.0)) (and (<= 0.0 u2) (<= u2 1.0)))
(+ (* (* (/ 1.0 6.0) (pow (* -2.0 (log u1)) 0.5)) (cos (* (* 2.0 PI) u2))) 0.5))