
(FPCore (x) :precision binary64 (- (/ 1.0 x) (/ 1.0 (tan x))))
double code(double x) {
return (1.0 / x) - (1.0 / tan(x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / x) - (1.0d0 / tan(x))
end function
public static double code(double x) {
return (1.0 / x) - (1.0 / Math.tan(x));
}
def code(x): return (1.0 / x) - (1.0 / math.tan(x))
function code(x) return Float64(Float64(1.0 / x) - Float64(1.0 / tan(x))) end
function tmp = code(x) tmp = (1.0 / x) - (1.0 / tan(x)); end
code[x_] := N[(N[(1.0 / x), $MachinePrecision] - N[(1.0 / N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x} - \frac{1}{\tan x}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (x) :precision binary64 (- (/ 1.0 x) (/ 1.0 (tan x))))
double code(double x) {
return (1.0 / x) - (1.0 / tan(x));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (1.0d0 / x) - (1.0d0 / tan(x))
end function
public static double code(double x) {
return (1.0 / x) - (1.0 / Math.tan(x));
}
def code(x): return (1.0 / x) - (1.0 / math.tan(x))
function code(x) return Float64(Float64(1.0 / x) - Float64(1.0 / tan(x))) end
function tmp = code(x) tmp = (1.0 / x) - (1.0 / tan(x)); end
code[x_] := N[(N[(1.0 / x), $MachinePrecision] - N[(1.0 / N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{x} - \frac{1}{\tan x}
\end{array}
(FPCore (x)
:precision binary64
(+
(* 0.3333333333333333 x)
(+
(* 0.0021164021164021165 (pow x 5.0))
(+
(* 0.022222222222222223 (pow x 3.0))
(* 0.00021164021164021165 (pow x 7.0))))))
double code(double x) {
return (0.3333333333333333 * x) + ((0.0021164021164021165 * pow(x, 5.0)) + ((0.022222222222222223 * pow(x, 3.0)) + (0.00021164021164021165 * pow(x, 7.0))));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (0.3333333333333333d0 * x) + ((0.0021164021164021165d0 * (x ** 5.0d0)) + ((0.022222222222222223d0 * (x ** 3.0d0)) + (0.00021164021164021165d0 * (x ** 7.0d0))))
end function
public static double code(double x) {
return (0.3333333333333333 * x) + ((0.0021164021164021165 * Math.pow(x, 5.0)) + ((0.022222222222222223 * Math.pow(x, 3.0)) + (0.00021164021164021165 * Math.pow(x, 7.0))));
}
def code(x): return (0.3333333333333333 * x) + ((0.0021164021164021165 * math.pow(x, 5.0)) + ((0.022222222222222223 * math.pow(x, 3.0)) + (0.00021164021164021165 * math.pow(x, 7.0))))
function code(x) return Float64(Float64(0.3333333333333333 * x) + Float64(Float64(0.0021164021164021165 * (x ^ 5.0)) + Float64(Float64(0.022222222222222223 * (x ^ 3.0)) + Float64(0.00021164021164021165 * (x ^ 7.0))))) end
function tmp = code(x) tmp = (0.3333333333333333 * x) + ((0.0021164021164021165 * (x ^ 5.0)) + ((0.022222222222222223 * (x ^ 3.0)) + (0.00021164021164021165 * (x ^ 7.0)))); end
code[x_] := N[(N[(0.3333333333333333 * x), $MachinePrecision] + N[(N[(0.0021164021164021165 * N[Power[x, 5.0], $MachinePrecision]), $MachinePrecision] + N[(N[(0.022222222222222223 * N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision] + N[(0.00021164021164021165 * N[Power[x, 7.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.3333333333333333 \cdot x + \left(0.0021164021164021165 \cdot {x}^{5} + \left(0.022222222222222223 \cdot {x}^{3} + 0.00021164021164021165 \cdot {x}^{7}\right)\right)
\end{array}
Initial program 6.3%
Taylor expanded in x around 0 99.5%
Final simplification99.5%
(FPCore (x) :precision binary64 (+ (* 0.3333333333333333 x) (+ (* 0.0021164021164021165 (pow x 5.0)) (* 0.022222222222222223 (pow x 3.0)))))
double code(double x) {
return (0.3333333333333333 * x) + ((0.0021164021164021165 * pow(x, 5.0)) + (0.022222222222222223 * pow(x, 3.0)));
}
real(8) function code(x)
real(8), intent (in) :: x
code = (0.3333333333333333d0 * x) + ((0.0021164021164021165d0 * (x ** 5.0d0)) + (0.022222222222222223d0 * (x ** 3.0d0)))
end function
public static double code(double x) {
return (0.3333333333333333 * x) + ((0.0021164021164021165 * Math.pow(x, 5.0)) + (0.022222222222222223 * Math.pow(x, 3.0)));
}
def code(x): return (0.3333333333333333 * x) + ((0.0021164021164021165 * math.pow(x, 5.0)) + (0.022222222222222223 * math.pow(x, 3.0)))
function code(x) return Float64(Float64(0.3333333333333333 * x) + Float64(Float64(0.0021164021164021165 * (x ^ 5.0)) + Float64(0.022222222222222223 * (x ^ 3.0)))) end
function tmp = code(x) tmp = (0.3333333333333333 * x) + ((0.0021164021164021165 * (x ^ 5.0)) + (0.022222222222222223 * (x ^ 3.0))); end
code[x_] := N[(N[(0.3333333333333333 * x), $MachinePrecision] + N[(N[(0.0021164021164021165 * N[Power[x, 5.0], $MachinePrecision]), $MachinePrecision] + N[(0.022222222222222223 * N[Power[x, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
0.3333333333333333 \cdot x + \left(0.0021164021164021165 \cdot {x}^{5} + 0.022222222222222223 \cdot {x}^{3}\right)
\end{array}
Initial program 6.3%
Taylor expanded in x around 0 99.4%
Final simplification99.4%
(FPCore (x) :precision binary64 (/ 1.0 (+ (/ 3.0 x) (* x -0.2))))
double code(double x) {
return 1.0 / ((3.0 / x) + (x * -0.2));
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0 / ((3.0d0 / x) + (x * (-0.2d0)))
end function
public static double code(double x) {
return 1.0 / ((3.0 / x) + (x * -0.2));
}
def code(x): return 1.0 / ((3.0 / x) + (x * -0.2))
function code(x) return Float64(1.0 / Float64(Float64(3.0 / x) + Float64(x * -0.2))) end
function tmp = code(x) tmp = 1.0 / ((3.0 / x) + (x * -0.2)); end
code[x_] := N[(1.0 / N[(N[(3.0 / x), $MachinePrecision] + N[(x * -0.2), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\frac{3}{x} + x \cdot -0.2}
\end{array}
Initial program 6.3%
Taylor expanded in x around 0 99.3%
flip-+53.5%
clear-num53.4%
cancel-sign-sub-inv53.4%
metadata-eval53.4%
pow253.4%
swap-sqr53.4%
metadata-eval53.4%
pow-prod-up53.4%
metadata-eval53.4%
Applied egg-rr53.4%
Taylor expanded in x around 0 99.2%
associate-*r/99.4%
metadata-eval99.4%
*-commutative99.4%
Simplified99.4%
Final simplification99.4%
(FPCore (x) :precision binary64 (/ 1.0 (/ 3.0 x)))
double code(double x) {
return 1.0 / (3.0 / x);
}
real(8) function code(x)
real(8), intent (in) :: x
code = 1.0d0 / (3.0d0 / x)
end function
public static double code(double x) {
return 1.0 / (3.0 / x);
}
def code(x): return 1.0 / (3.0 / x)
function code(x) return Float64(1.0 / Float64(3.0 / x)) end
function tmp = code(x) tmp = 1.0 / (3.0 / x); end
code[x_] := N[(1.0 / N[(3.0 / x), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{1}{\frac{3}{x}}
\end{array}
Initial program 6.3%
Taylor expanded in x around 0 99.3%
flip-+53.5%
clear-num53.4%
cancel-sign-sub-inv53.4%
metadata-eval53.4%
pow253.4%
swap-sqr53.4%
metadata-eval53.4%
pow-prod-up53.4%
metadata-eval53.4%
Applied egg-rr53.4%
Taylor expanded in x around 0 99.0%
Final simplification99.0%
(FPCore (x) :precision binary64 (* 0.3333333333333333 x))
double code(double x) {
return 0.3333333333333333 * x;
}
real(8) function code(x)
real(8), intent (in) :: x
code = 0.3333333333333333d0 * x
end function
public static double code(double x) {
return 0.3333333333333333 * x;
}
def code(x): return 0.3333333333333333 * x
function code(x) return Float64(0.3333333333333333 * x) end
function tmp = code(x) tmp = 0.3333333333333333 * x; end
code[x_] := N[(0.3333333333333333 * x), $MachinePrecision]
\begin{array}{l}
\\
0.3333333333333333 \cdot x
\end{array}
Initial program 6.3%
Taylor expanded in x around 0 98.9%
Final simplification98.9%
(FPCore (x) :precision binary64 (if (< (fabs x) 0.026) (* (/ x 3.0) (+ 1.0 (/ (* x x) 15.0))) (- (/ 1.0 x) (/ 1.0 (tan x)))))
double code(double x) {
double tmp;
if (fabs(x) < 0.026) {
tmp = (x / 3.0) * (1.0 + ((x * x) / 15.0));
} else {
tmp = (1.0 / x) - (1.0 / tan(x));
}
return tmp;
}
real(8) function code(x)
real(8), intent (in) :: x
real(8) :: tmp
if (abs(x) < 0.026d0) then
tmp = (x / 3.0d0) * (1.0d0 + ((x * x) / 15.0d0))
else
tmp = (1.0d0 / x) - (1.0d0 / tan(x))
end if
code = tmp
end function
public static double code(double x) {
double tmp;
if (Math.abs(x) < 0.026) {
tmp = (x / 3.0) * (1.0 + ((x * x) / 15.0));
} else {
tmp = (1.0 / x) - (1.0 / Math.tan(x));
}
return tmp;
}
def code(x): tmp = 0 if math.fabs(x) < 0.026: tmp = (x / 3.0) * (1.0 + ((x * x) / 15.0)) else: tmp = (1.0 / x) - (1.0 / math.tan(x)) return tmp
function code(x) tmp = 0.0 if (abs(x) < 0.026) tmp = Float64(Float64(x / 3.0) * Float64(1.0 + Float64(Float64(x * x) / 15.0))); else tmp = Float64(Float64(1.0 / x) - Float64(1.0 / tan(x))); end return tmp end
function tmp_2 = code(x) tmp = 0.0; if (abs(x) < 0.026) tmp = (x / 3.0) * (1.0 + ((x * x) / 15.0)); else tmp = (1.0 / x) - (1.0 / tan(x)); end tmp_2 = tmp; end
code[x_] := If[Less[N[Abs[x], $MachinePrecision], 0.026], N[(N[(x / 3.0), $MachinePrecision] * N[(1.0 + N[(N[(x * x), $MachinePrecision] / 15.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / x), $MachinePrecision] - N[(1.0 / N[Tan[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\left|x\right| < 0.026:\\
\;\;\;\;\frac{x}{3} \cdot \left(1 + \frac{x \cdot x}{15}\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{x} - \frac{1}{\tan x}\\
\end{array}
\end{array}
herbie shell --seed 2023192
(FPCore (x)
:name "invcot (example 3.9)"
:precision binary64
:pre (and (< -0.026 x) (< x 0.026))
:herbie-target
(if (< (fabs x) 0.026) (* (/ x 3.0) (+ 1.0 (/ (* x x) 15.0))) (- (/ 1.0 x) (/ 1.0 (tan x))))
(- (/ 1.0 x) (/ 1.0 (tan x))))