
(FPCore (v) :precision binary64 (/ 4.0 (* (* (* 3.0 PI) (- 1.0 (* v v))) (sqrt (- 2.0 (* 6.0 (* v v)))))))
double code(double v) {
return 4.0 / (((3.0 * ((double) M_PI)) * (1.0 - (v * v))) * sqrt((2.0 - (6.0 * (v * v)))));
}
public static double code(double v) {
return 4.0 / (((3.0 * Math.PI) * (1.0 - (v * v))) * Math.sqrt((2.0 - (6.0 * (v * v)))));
}
def code(v): return 4.0 / (((3.0 * math.pi) * (1.0 - (v * v))) * math.sqrt((2.0 - (6.0 * (v * v)))))
function code(v) return Float64(4.0 / Float64(Float64(Float64(3.0 * pi) * Float64(1.0 - Float64(v * v))) * sqrt(Float64(2.0 - Float64(6.0 * Float64(v * v)))))) end
function tmp = code(v) tmp = 4.0 / (((3.0 * pi) * (1.0 - (v * v))) * sqrt((2.0 - (6.0 * (v * v))))); end
code[v_] := N[(4.0 / N[(N[(N[(3.0 * Pi), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[(2.0 - N[(6.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 4 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (v) :precision binary64 (/ 4.0 (* (* (* 3.0 PI) (- 1.0 (* v v))) (sqrt (- 2.0 (* 6.0 (* v v)))))))
double code(double v) {
return 4.0 / (((3.0 * ((double) M_PI)) * (1.0 - (v * v))) * sqrt((2.0 - (6.0 * (v * v)))));
}
public static double code(double v) {
return 4.0 / (((3.0 * Math.PI) * (1.0 - (v * v))) * Math.sqrt((2.0 - (6.0 * (v * v)))));
}
def code(v): return 4.0 / (((3.0 * math.pi) * (1.0 - (v * v))) * math.sqrt((2.0 - (6.0 * (v * v)))))
function code(v) return Float64(4.0 / Float64(Float64(Float64(3.0 * pi) * Float64(1.0 - Float64(v * v))) * sqrt(Float64(2.0 - Float64(6.0 * Float64(v * v)))))) end
function tmp = code(v) tmp = 4.0 / (((3.0 * pi) * (1.0 - (v * v))) * sqrt((2.0 - (6.0 * (v * v))))); end
code[v_] := N[(4.0 / N[(N[(N[(3.0 * Pi), $MachinePrecision] * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[(2.0 - N[(6.0 * N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}
\end{array}
(FPCore (v) :precision binary64 (/ 1.3333333333333333 (* (sqrt (+ 2.0 (* v (* v -6.0)))) (* PI (- 1.0 (* v v))))))
double code(double v) {
return 1.3333333333333333 / (sqrt((2.0 + (v * (v * -6.0)))) * (((double) M_PI) * (1.0 - (v * v))));
}
public static double code(double v) {
return 1.3333333333333333 / (Math.sqrt((2.0 + (v * (v * -6.0)))) * (Math.PI * (1.0 - (v * v))));
}
def code(v): return 1.3333333333333333 / (math.sqrt((2.0 + (v * (v * -6.0)))) * (math.pi * (1.0 - (v * v))))
function code(v) return Float64(1.3333333333333333 / Float64(sqrt(Float64(2.0 + Float64(v * Float64(v * -6.0)))) * Float64(pi * Float64(1.0 - Float64(v * v))))) end
function tmp = code(v) tmp = 1.3333333333333333 / (sqrt((2.0 + (v * (v * -6.0)))) * (pi * (1.0 - (v * v)))); end
code[v_] := N[(1.3333333333333333 / N[(N[Sqrt[N[(2.0 + N[(v * N[(v * -6.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * N[(Pi * N[(1.0 - N[(v * v), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1.3333333333333333}{\sqrt{2 + v \cdot \left(v \cdot -6\right)} \cdot \left(\pi \cdot \left(1 - v \cdot v\right)\right)}
\end{array}
Initial program 98.5%
expm1-log1p-u98.5%
expm1-udef98.4%
Applied egg-rr98.4%
expm1-def100.0%
expm1-log1p100.0%
associate-/l/100.0%
associate-*l*100.0%
Simplified100.0%
Final simplification100.0%
(FPCore (v) :precision binary64 (/ 1.3333333333333333 (* (sqrt (+ 2.0 (* v (* v -6.0)))) PI)))
double code(double v) {
return 1.3333333333333333 / (sqrt((2.0 + (v * (v * -6.0)))) * ((double) M_PI));
}
public static double code(double v) {
return 1.3333333333333333 / (Math.sqrt((2.0 + (v * (v * -6.0)))) * Math.PI);
}
def code(v): return 1.3333333333333333 / (math.sqrt((2.0 + (v * (v * -6.0)))) * math.pi)
function code(v) return Float64(1.3333333333333333 / Float64(sqrt(Float64(2.0 + Float64(v * Float64(v * -6.0)))) * pi)) end
function tmp = code(v) tmp = 1.3333333333333333 / (sqrt((2.0 + (v * (v * -6.0)))) * pi); end
code[v_] := N[(1.3333333333333333 / N[(N[Sqrt[N[(2.0 + N[(v * N[(v * -6.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * Pi), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1.3333333333333333}{\sqrt{2 + v \cdot \left(v \cdot -6\right)} \cdot \pi}
\end{array}
Initial program 98.5%
expm1-log1p-u98.5%
expm1-udef98.4%
Applied egg-rr98.4%
expm1-def100.0%
expm1-log1p100.0%
associate-/l/100.0%
associate-*l*100.0%
Simplified100.0%
Taylor expanded in v around 0 99.1%
Final simplification99.1%
(FPCore (v) :precision binary64 (/ (* 1.3333333333333333 (sqrt 0.5)) PI))
double code(double v) {
return (1.3333333333333333 * sqrt(0.5)) / ((double) M_PI);
}
public static double code(double v) {
return (1.3333333333333333 * Math.sqrt(0.5)) / Math.PI;
}
def code(v): return (1.3333333333333333 * math.sqrt(0.5)) / math.pi
function code(v) return Float64(Float64(1.3333333333333333 * sqrt(0.5)) / pi) end
function tmp = code(v) tmp = (1.3333333333333333 * sqrt(0.5)) / pi; end
code[v_] := N[(N[(1.3333333333333333 * N[Sqrt[0.5], $MachinePrecision]), $MachinePrecision] / Pi), $MachinePrecision]
\begin{array}{l}
\\
\frac{1.3333333333333333 \cdot \sqrt{0.5}}{\pi}
\end{array}
Initial program 98.5%
Taylor expanded in v around 0 97.5%
associate-*r/97.5%
Simplified97.5%
Final simplification97.5%
(FPCore (v) :precision binary64 (/ (/ 1.3333333333333333 PI) (sqrt 2.0)))
double code(double v) {
return (1.3333333333333333 / ((double) M_PI)) / sqrt(2.0);
}
public static double code(double v) {
return (1.3333333333333333 / Math.PI) / Math.sqrt(2.0);
}
def code(v): return (1.3333333333333333 / math.pi) / math.sqrt(2.0)
function code(v) return Float64(Float64(1.3333333333333333 / pi) / sqrt(2.0)) end
function tmp = code(v) tmp = (1.3333333333333333 / pi) / sqrt(2.0); end
code[v_] := N[(N[(1.3333333333333333 / Pi), $MachinePrecision] / N[Sqrt[2.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\frac{1.3333333333333333}{\pi}}{\sqrt{2}}
\end{array}
Initial program 98.5%
associate-/r*100.0%
associate-*l*100.0%
sqr-neg100.0%
associate-/r*100.0%
metadata-eval100.0%
sqr-neg100.0%
Simplified100.0%
Taylor expanded in v around 0 99.1%
Taylor expanded in v around 0 99.0%
Final simplification99.0%
herbie shell --seed 2023292
(FPCore (v)
:name "Falkner and Boettcher, Equation (22+)"
:precision binary64
(/ 4.0 (* (* (* 3.0 PI) (- 1.0 (* v v))) (sqrt (- 2.0 (* 6.0 (* v v)))))))