
(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 4 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 (+ (* (* (/ 1.0 6.0) (* (sqrt (log (/ 1.0 u1))) (sqrt 2.0))) (cos (* (* 2.0 PI) u2))) 0.5))
double code(double u1, double u2) {
return (((1.0 / 6.0) * (sqrt(log((1.0 / u1))) * sqrt(2.0))) * cos(((2.0 * ((double) M_PI)) * u2))) + 0.5;
}
public static double code(double u1, double u2) {
return (((1.0 / 6.0) * (Math.sqrt(Math.log((1.0 / u1))) * Math.sqrt(2.0))) * Math.cos(((2.0 * Math.PI) * u2))) + 0.5;
}
def code(u1, u2): return (((1.0 / 6.0) * (math.sqrt(math.log((1.0 / u1))) * math.sqrt(2.0))) * math.cos(((2.0 * math.pi) * u2))) + 0.5
function code(u1, u2) return Float64(Float64(Float64(Float64(1.0 / 6.0) * Float64(sqrt(log(Float64(1.0 / u1))) * sqrt(2.0))) * cos(Float64(Float64(2.0 * pi) * u2))) + 0.5) end
function tmp = code(u1, u2) tmp = (((1.0 / 6.0) * (sqrt(log((1.0 / u1))) * sqrt(2.0))) * cos(((2.0 * pi) * u2))) + 0.5; end
code[u1_, u2_] := N[(N[(N[(N[(1.0 / 6.0), $MachinePrecision] * N[(N[Sqrt[N[Log[N[(1.0 / u1), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] * N[Sqrt[2.0], $MachinePrecision]), $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(\sqrt{\log \left(\frac{1}{u1}\right)} \cdot \sqrt{2}\right)\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
*-lowering-*.f64N/A
sqrt-lowering-sqrt.f64N/A
log-lowering-log.f64N/A
/-lowering-/.f64N/A
sqrt-lowering-sqrt.f6499.5%
Simplified99.5%
(FPCore (u1 u2) :precision binary64 (+ 0.5 (* (* (cos (* 2.0 (* PI u2))) (sqrt (* -2.0 (log u1)))) 0.16666666666666666)))
double code(double u1, double u2) {
return 0.5 + ((cos((2.0 * (((double) M_PI) * u2))) * sqrt((-2.0 * log(u1)))) * 0.16666666666666666);
}
public static double code(double u1, double u2) {
return 0.5 + ((Math.cos((2.0 * (Math.PI * u2))) * Math.sqrt((-2.0 * Math.log(u1)))) * 0.16666666666666666);
}
def code(u1, u2): return 0.5 + ((math.cos((2.0 * (math.pi * u2))) * math.sqrt((-2.0 * math.log(u1)))) * 0.16666666666666666)
function code(u1, u2) return Float64(0.5 + Float64(Float64(cos(Float64(2.0 * Float64(pi * u2))) * sqrt(Float64(-2.0 * log(u1)))) * 0.16666666666666666)) end
function tmp = code(u1, u2) tmp = 0.5 + ((cos((2.0 * (pi * u2))) * sqrt((-2.0 * log(u1)))) * 0.16666666666666666); end
code[u1_, u2_] := N[(0.5 + N[(N[(N[Cos[N[(2.0 * N[(Pi * u2), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[(-2.0 * N[Log[u1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 + \left(\cos \left(2 \cdot \left(\pi \cdot u2\right)\right) \cdot \sqrt{-2 \cdot \log u1}\right) \cdot 0.16666666666666666
\end{array}
Initial program 99.4%
associate-*l*N/A
*-commutativeN/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
unpow1/2N/A
sqrt-lowering-sqrt.f64N/A
*-lowering-*.f64N/A
log-lowering-log.f64N/A
cos-lowering-cos.f64N/A
associate-*l*N/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
PI-lowering-PI.f64N/A
metadata-eval99.4%
Applied egg-rr99.4%
Final simplification99.4%
(FPCore (u1 u2) :precision binary64 (- (* 0.16666666666666666 (* (+ 1.0 (* u2 (* u2 (* -2.0 (* PI PI))))) (sqrt (* -2.0 (log u1))))) -0.5))
double code(double u1, double u2) {
return (0.16666666666666666 * ((1.0 + (u2 * (u2 * (-2.0 * (((double) M_PI) * ((double) M_PI)))))) * sqrt((-2.0 * log(u1))))) - -0.5;
}
public static double code(double u1, double u2) {
return (0.16666666666666666 * ((1.0 + (u2 * (u2 * (-2.0 * (Math.PI * Math.PI))))) * Math.sqrt((-2.0 * Math.log(u1))))) - -0.5;
}
def code(u1, u2): return (0.16666666666666666 * ((1.0 + (u2 * (u2 * (-2.0 * (math.pi * math.pi))))) * math.sqrt((-2.0 * math.log(u1))))) - -0.5
function code(u1, u2) return Float64(Float64(0.16666666666666666 * Float64(Float64(1.0 + Float64(u2 * Float64(u2 * Float64(-2.0 * Float64(pi * pi))))) * sqrt(Float64(-2.0 * log(u1))))) - -0.5) end
function tmp = code(u1, u2) tmp = (0.16666666666666666 * ((1.0 + (u2 * (u2 * (-2.0 * (pi * pi))))) * sqrt((-2.0 * log(u1))))) - -0.5; end
code[u1_, u2_] := N[(N[(0.16666666666666666 * N[(N[(1.0 + N[(u2 * N[(u2 * N[(-2.0 * N[(Pi * Pi), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[(-2.0 * N[Log[u1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - -0.5), $MachinePrecision]
\begin{array}{l}
\\
0.16666666666666666 \cdot \left(\left(1 + u2 \cdot \left(u2 \cdot \left(-2 \cdot \left(\pi \cdot \pi\right)\right)\right)\right) \cdot \sqrt{-2 \cdot \log u1}\right) - -0.5
\end{array}
Initial program 99.4%
sqr-powN/A
pow2N/A
pow-lowering-pow.f64N/A
metadata-evalN/A
metadata-evalN/A
pow-lowering-pow.f64N/A
*-lowering-*.f64N/A
log-lowering-log.f64N/A
metadata-eval99.2%
Applied egg-rr99.2%
Applied egg-rr99.4%
Taylor expanded in u2 around 0
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
+-lowering-+.f64N/A
unpow2N/A
associate-*l*N/A
*-commutativeN/A
*-lowering-*.f64N/A
*-commutativeN/A
*-lowering-*.f64N/A
*-lowering-*.f64N/A
unpow2N/A
*-lowering-*.f64N/A
PI-lowering-PI.f64N/A
PI-lowering-PI.f6499.2%
Simplified99.2%
Final simplification99.2%
(FPCore (u1 u2) :precision binary64 (+ 0.5 (* 0.16666666666666666 (sqrt (* -2.0 (log u1))))))
double code(double u1, double u2) {
return 0.5 + (0.16666666666666666 * sqrt((-2.0 * log(u1))));
}
real(8) function code(u1, u2)
real(8), intent (in) :: u1
real(8), intent (in) :: u2
code = 0.5d0 + (0.16666666666666666d0 * sqrt(((-2.0d0) * log(u1))))
end function
public static double code(double u1, double u2) {
return 0.5 + (0.16666666666666666 * Math.sqrt((-2.0 * Math.log(u1))));
}
def code(u1, u2): return 0.5 + (0.16666666666666666 * math.sqrt((-2.0 * math.log(u1))))
function code(u1, u2) return Float64(0.5 + Float64(0.16666666666666666 * sqrt(Float64(-2.0 * log(u1))))) end
function tmp = code(u1, u2) tmp = 0.5 + (0.16666666666666666 * sqrt((-2.0 * log(u1)))); end
code[u1_, u2_] := N[(0.5 + N[(0.16666666666666666 * N[Sqrt[N[(-2.0 * N[Log[u1], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.5 + 0.16666666666666666 \cdot \sqrt{-2 \cdot \log u1}
\end{array}
Initial program 99.4%
Taylor expanded in u2 around 0
*-commutativeN/A
associate-*l*N/A
*-commutativeN/A
*-lowering-*.f64N/A
sqrt-lowering-sqrt.f64N/A
log-lowering-log.f64N/A
*-commutativeN/A
*-lowering-*.f64N/A
sqrt-lowering-sqrt.f640.0%
Simplified0.0%
*-commutativeN/A
metadata-evalN/A
*-commutativeN/A
associate-*r*N/A
sqrt-prodN/A
*-commutativeN/A
*-lowering-*.f64N/A
unpow1N/A
metadata-evalN/A
sqrt-pow2N/A
sqrt-lowering-sqrt.f64N/A
sqrt-pow2N/A
metadata-evalN/A
unpow1N/A
*-commutativeN/A
*-lowering-*.f64N/A
log-lowering-log.f64N/A
metadata-eval98.9%
Applied egg-rr98.9%
Final simplification98.9%
herbie shell --seed 2024192
(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))