Maksimov and Kolovsky, Equation (3)

Percentage Accurate: 72.4% → 99.2%
Time: 11.7s
Alternatives: 7
Speedup: 1.9×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ \left(\left(-2 \cdot J\right) \cdot t_0\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot t_0}\right)}^{2}} \end{array} \end{array} \]
(FPCore (J K U)
 :precision binary64
 (let* ((t_0 (cos (/ K 2.0))))
   (* (* (* -2.0 J) t_0) (sqrt (+ 1.0 (pow (/ U (* (* 2.0 J) t_0)) 2.0))))))
double code(double J, double K, double U) {
	double t_0 = cos((K / 2.0));
	return ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U / ((2.0 * J) * t_0)), 2.0)));
}
real(8) function code(j, k, u)
    real(8), intent (in) :: j
    real(8), intent (in) :: k
    real(8), intent (in) :: u
    real(8) :: t_0
    t_0 = cos((k / 2.0d0))
    code = (((-2.0d0) * j) * t_0) * sqrt((1.0d0 + ((u / ((2.0d0 * j) * t_0)) ** 2.0d0)))
end function
public static double code(double J, double K, double U) {
	double t_0 = Math.cos((K / 2.0));
	return ((-2.0 * J) * t_0) * Math.sqrt((1.0 + Math.pow((U / ((2.0 * J) * t_0)), 2.0)));
}
def code(J, K, U):
	t_0 = math.cos((K / 2.0))
	return ((-2.0 * J) * t_0) * math.sqrt((1.0 + math.pow((U / ((2.0 * J) * t_0)), 2.0)))
function code(J, K, U)
	t_0 = cos(Float64(K / 2.0))
	return Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U / Float64(Float64(2.0 * J) * t_0)) ^ 2.0))))
end
function tmp = code(J, K, U)
	t_0 = cos((K / 2.0));
	tmp = ((-2.0 * J) * t_0) * sqrt((1.0 + ((U / ((2.0 * J) * t_0)) ^ 2.0)));
end
code[J_, K_, U_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos \left(\frac{K}{2}\right)\\
\left(\left(-2 \cdot J\right) \cdot t_0\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot t_0}\right)}^{2}}
\end{array}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 7 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 72.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ \left(\left(-2 \cdot J\right) \cdot t_0\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot t_0}\right)}^{2}} \end{array} \end{array} \]
(FPCore (J K U)
 :precision binary64
 (let* ((t_0 (cos (/ K 2.0))))
   (* (* (* -2.0 J) t_0) (sqrt (+ 1.0 (pow (/ U (* (* 2.0 J) t_0)) 2.0))))))
double code(double J, double K, double U) {
	double t_0 = cos((K / 2.0));
	return ((-2.0 * J) * t_0) * sqrt((1.0 + pow((U / ((2.0 * J) * t_0)), 2.0)));
}
real(8) function code(j, k, u)
    real(8), intent (in) :: j
    real(8), intent (in) :: k
    real(8), intent (in) :: u
    real(8) :: t_0
    t_0 = cos((k / 2.0d0))
    code = (((-2.0d0) * j) * t_0) * sqrt((1.0d0 + ((u / ((2.0d0 * j) * t_0)) ** 2.0d0)))
end function
public static double code(double J, double K, double U) {
	double t_0 = Math.cos((K / 2.0));
	return ((-2.0 * J) * t_0) * Math.sqrt((1.0 + Math.pow((U / ((2.0 * J) * t_0)), 2.0)));
}
def code(J, K, U):
	t_0 = math.cos((K / 2.0))
	return ((-2.0 * J) * t_0) * math.sqrt((1.0 + math.pow((U / ((2.0 * J) * t_0)), 2.0)))
function code(J, K, U)
	t_0 = cos(Float64(K / 2.0))
	return Float64(Float64(Float64(-2.0 * J) * t_0) * sqrt(Float64(1.0 + (Float64(U / Float64(Float64(2.0 * J) * t_0)) ^ 2.0))))
end
function tmp = code(J, K, U)
	t_0 = cos((K / 2.0));
	tmp = ((-2.0 * J) * t_0) * sqrt((1.0 + ((U / ((2.0 * J) * t_0)) ^ 2.0)));
end
code[J_, K_, U_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, N[(N[(N[(-2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U / N[(N[(2.0 * J), $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \cos \left(\frac{K}{2}\right)\\
\left(\left(-2 \cdot J\right) \cdot t_0\right) \cdot \sqrt{1 + {\left(\frac{U}{\left(2 \cdot J\right) \cdot t_0}\right)}^{2}}
\end{array}
\end{array}

Alternative 1: 99.2% accurate, 0.4× speedup?

\[\begin{array}{l} U_m = \left|U\right| \\ J_m = \left|J\right| \\ J_s = \mathsf{copysign}\left(1, J\right) \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ t_1 := J_m \cdot t_0\\ t_2 := \left(\left(-2 \cdot J_m\right) \cdot t_0\right) \cdot \sqrt{1 + {\left(\frac{U_m}{t_0 \cdot \left(J_m \cdot 2\right)}\right)}^{2}}\\ J_s \cdot \begin{array}{l} \mathbf{if}\;t_2 \leq -\infty:\\ \;\;\;\;-2 \cdot \left(U_m \cdot 0.5\right)\\ \mathbf{elif}\;t_2 \leq 2 \cdot 10^{+289}:\\ \;\;\;\;-2 \cdot \left(t_1 \cdot \mathsf{hypot}\left(1, \frac{\frac{U_m}{2}}{t_1}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot \left(U_m \cdot -0.5\right)\\ \end{array} \end{array} \end{array} \]
U_m = (fabs.f64 U)
J_m = (fabs.f64 J)
J_s = (copysign.f64 1 J)
(FPCore (J_s J_m K U_m)
 :precision binary64
 (let* ((t_0 (cos (/ K 2.0)))
        (t_1 (* J_m t_0))
        (t_2
         (*
          (* (* -2.0 J_m) t_0)
          (sqrt (+ 1.0 (pow (/ U_m (* t_0 (* J_m 2.0))) 2.0))))))
   (*
    J_s
    (if (<= t_2 (- INFINITY))
      (* -2.0 (* U_m 0.5))
      (if (<= t_2 2e+289)
        (* -2.0 (* t_1 (hypot 1.0 (/ (/ U_m 2.0) t_1))))
        (* -2.0 (* U_m -0.5)))))))
U_m = fabs(U);
J_m = fabs(J);
J_s = copysign(1.0, J);
double code(double J_s, double J_m, double K, double U_m) {
	double t_0 = cos((K / 2.0));
	double t_1 = J_m * t_0;
	double t_2 = ((-2.0 * J_m) * t_0) * sqrt((1.0 + pow((U_m / (t_0 * (J_m * 2.0))), 2.0)));
	double tmp;
	if (t_2 <= -((double) INFINITY)) {
		tmp = -2.0 * (U_m * 0.5);
	} else if (t_2 <= 2e+289) {
		tmp = -2.0 * (t_1 * hypot(1.0, ((U_m / 2.0) / t_1)));
	} else {
		tmp = -2.0 * (U_m * -0.5);
	}
	return J_s * tmp;
}
U_m = Math.abs(U);
J_m = Math.abs(J);
J_s = Math.copySign(1.0, J);
public static double code(double J_s, double J_m, double K, double U_m) {
	double t_0 = Math.cos((K / 2.0));
	double t_1 = J_m * t_0;
	double t_2 = ((-2.0 * J_m) * t_0) * Math.sqrt((1.0 + Math.pow((U_m / (t_0 * (J_m * 2.0))), 2.0)));
	double tmp;
	if (t_2 <= -Double.POSITIVE_INFINITY) {
		tmp = -2.0 * (U_m * 0.5);
	} else if (t_2 <= 2e+289) {
		tmp = -2.0 * (t_1 * Math.hypot(1.0, ((U_m / 2.0) / t_1)));
	} else {
		tmp = -2.0 * (U_m * -0.5);
	}
	return J_s * tmp;
}
U_m = math.fabs(U)
J_m = math.fabs(J)
J_s = math.copysign(1.0, J)
def code(J_s, J_m, K, U_m):
	t_0 = math.cos((K / 2.0))
	t_1 = J_m * t_0
	t_2 = ((-2.0 * J_m) * t_0) * math.sqrt((1.0 + math.pow((U_m / (t_0 * (J_m * 2.0))), 2.0)))
	tmp = 0
	if t_2 <= -math.inf:
		tmp = -2.0 * (U_m * 0.5)
	elif t_2 <= 2e+289:
		tmp = -2.0 * (t_1 * math.hypot(1.0, ((U_m / 2.0) / t_1)))
	else:
		tmp = -2.0 * (U_m * -0.5)
	return J_s * tmp
U_m = abs(U)
J_m = abs(J)
J_s = copysign(1.0, J)
function code(J_s, J_m, K, U_m)
	t_0 = cos(Float64(K / 2.0))
	t_1 = Float64(J_m * t_0)
	t_2 = Float64(Float64(Float64(-2.0 * J_m) * t_0) * sqrt(Float64(1.0 + (Float64(U_m / Float64(t_0 * Float64(J_m * 2.0))) ^ 2.0))))
	tmp = 0.0
	if (t_2 <= Float64(-Inf))
		tmp = Float64(-2.0 * Float64(U_m * 0.5));
	elseif (t_2 <= 2e+289)
		tmp = Float64(-2.0 * Float64(t_1 * hypot(1.0, Float64(Float64(U_m / 2.0) / t_1))));
	else
		tmp = Float64(-2.0 * Float64(U_m * -0.5));
	end
	return Float64(J_s * tmp)
end
U_m = abs(U);
J_m = abs(J);
J_s = sign(J) * abs(1.0);
function tmp_2 = code(J_s, J_m, K, U_m)
	t_0 = cos((K / 2.0));
	t_1 = J_m * t_0;
	t_2 = ((-2.0 * J_m) * t_0) * sqrt((1.0 + ((U_m / (t_0 * (J_m * 2.0))) ^ 2.0)));
	tmp = 0.0;
	if (t_2 <= -Inf)
		tmp = -2.0 * (U_m * 0.5);
	elseif (t_2 <= 2e+289)
		tmp = -2.0 * (t_1 * hypot(1.0, ((U_m / 2.0) / t_1)));
	else
		tmp = -2.0 * (U_m * -0.5);
	end
	tmp_2 = J_s * tmp;
end
U_m = N[Abs[U], $MachinePrecision]
J_m = N[Abs[J], $MachinePrecision]
J_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[J$95$s_, J$95$m_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(J$95$m * t$95$0), $MachinePrecision]}, Block[{t$95$2 = N[(N[(N[(-2.0 * J$95$m), $MachinePrecision] * t$95$0), $MachinePrecision] * N[Sqrt[N[(1.0 + N[Power[N[(U$95$m / N[(t$95$0 * N[(J$95$m * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(J$95$s * If[LessEqual[t$95$2, (-Infinity)], N[(-2.0 * N[(U$95$m * 0.5), $MachinePrecision]), $MachinePrecision], If[LessEqual[t$95$2, 2e+289], N[(-2.0 * N[(t$95$1 * N[Sqrt[1.0 ^ 2 + N[(N[(U$95$m / 2.0), $MachinePrecision] / t$95$1), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(-2.0 * N[(U$95$m * -0.5), $MachinePrecision]), $MachinePrecision]]]), $MachinePrecision]]]]
\begin{array}{l}
U_m = \left|U\right|
\\
J_m = \left|J\right|
\\
J_s = \mathsf{copysign}\left(1, J\right)

\\
\begin{array}{l}
t_0 := \cos \left(\frac{K}{2}\right)\\
t_1 := J_m \cdot t_0\\
t_2 := \left(\left(-2 \cdot J_m\right) \cdot t_0\right) \cdot \sqrt{1 + {\left(\frac{U_m}{t_0 \cdot \left(J_m \cdot 2\right)}\right)}^{2}}\\
J_s \cdot \begin{array}{l}
\mathbf{if}\;t_2 \leq -\infty:\\
\;\;\;\;-2 \cdot \left(U_m \cdot 0.5\right)\\

\mathbf{elif}\;t_2 \leq 2 \cdot 10^{+289}:\\
\;\;\;\;-2 \cdot \left(t_1 \cdot \mathsf{hypot}\left(1, \frac{\frac{U_m}{2}}{t_1}\right)\right)\\

\mathbf{else}:\\
\;\;\;\;-2 \cdot \left(U_m \cdot -0.5\right)\\


\end{array}
\end{array}
\end{array}
Derivation
    &prev;&pcontext;&pcontext2;&ctx;
  1. Add Preprocessing

Alternative 2: 88.8% accurate, 1.3× speedup?

\[\begin{array}{l} U_m = \left|U\right| \\ J_m = \left|J\right| \\ J_s = \mathsf{copysign}\left(1, J\right) \\ J_s \cdot \begin{array}{l} \mathbf{if}\;U_m \leq 8 \cdot 10^{+255}:\\ \;\;\;\;-2 \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \left(J_m \cdot \mathsf{hypot}\left(1, \frac{0.5 \cdot \frac{U_m}{J_m}}{\cos \left(K \cdot 0.5\right)}\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot \left(U_m \cdot 0.5\right)\\ \end{array} \end{array} \]
U_m = (fabs.f64 U)
J_m = (fabs.f64 J)
J_s = (copysign.f64 1 J)
(FPCore (J_s J_m K U_m)
 :precision binary64
 (*
  J_s
  (if (<= U_m 8e+255)
    (*
     -2.0
     (*
      (cos (/ K 2.0))
      (* J_m (hypot 1.0 (/ (* 0.5 (/ U_m J_m)) (cos (* K 0.5)))))))
    (* -2.0 (* U_m 0.5)))))
U_m = fabs(U);
J_m = fabs(J);
J_s = copysign(1.0, J);
double code(double J_s, double J_m, double K, double U_m) {
	double tmp;
	if (U_m <= 8e+255) {
		tmp = -2.0 * (cos((K / 2.0)) * (J_m * hypot(1.0, ((0.5 * (U_m / J_m)) / cos((K * 0.5))))));
	} else {
		tmp = -2.0 * (U_m * 0.5);
	}
	return J_s * tmp;
}
U_m = Math.abs(U);
J_m = Math.abs(J);
J_s = Math.copySign(1.0, J);
public static double code(double J_s, double J_m, double K, double U_m) {
	double tmp;
	if (U_m <= 8e+255) {
		tmp = -2.0 * (Math.cos((K / 2.0)) * (J_m * Math.hypot(1.0, ((0.5 * (U_m / J_m)) / Math.cos((K * 0.5))))));
	} else {
		tmp = -2.0 * (U_m * 0.5);
	}
	return J_s * tmp;
}
U_m = math.fabs(U)
J_m = math.fabs(J)
J_s = math.copysign(1.0, J)
def code(J_s, J_m, K, U_m):
	tmp = 0
	if U_m <= 8e+255:
		tmp = -2.0 * (math.cos((K / 2.0)) * (J_m * math.hypot(1.0, ((0.5 * (U_m / J_m)) / math.cos((K * 0.5))))))
	else:
		tmp = -2.0 * (U_m * 0.5)
	return J_s * tmp
U_m = abs(U)
J_m = abs(J)
J_s = copysign(1.0, J)
function code(J_s, J_m, K, U_m)
	tmp = 0.0
	if (U_m <= 8e+255)
		tmp = Float64(-2.0 * Float64(cos(Float64(K / 2.0)) * Float64(J_m * hypot(1.0, Float64(Float64(0.5 * Float64(U_m / J_m)) / cos(Float64(K * 0.5)))))));
	else
		tmp = Float64(-2.0 * Float64(U_m * 0.5));
	end
	return Float64(J_s * tmp)
end
U_m = abs(U);
J_m = abs(J);
J_s = sign(J) * abs(1.0);
function tmp_2 = code(J_s, J_m, K, U_m)
	tmp = 0.0;
	if (U_m <= 8e+255)
		tmp = -2.0 * (cos((K / 2.0)) * (J_m * hypot(1.0, ((0.5 * (U_m / J_m)) / cos((K * 0.5))))));
	else
		tmp = -2.0 * (U_m * 0.5);
	end
	tmp_2 = J_s * tmp;
end
U_m = N[Abs[U], $MachinePrecision]
J_m = N[Abs[J], $MachinePrecision]
J_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[J$95$s_, J$95$m_, K_, U$95$m_] := N[(J$95$s * If[LessEqual[U$95$m, 8e+255], N[(-2.0 * N[(N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision] * N[(J$95$m * N[Sqrt[1.0 ^ 2 + N[(N[(0.5 * N[(U$95$m / J$95$m), $MachinePrecision]), $MachinePrecision] / N[Cos[N[(K * 0.5), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(-2.0 * N[(U$95$m * 0.5), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]
\begin{array}{l}
U_m = \left|U\right|
\\
J_m = \left|J\right|
\\
J_s = \mathsf{copysign}\left(1, J\right)

\\
J_s \cdot \begin{array}{l}
\mathbf{if}\;U_m \leq 8 \cdot 10^{+255}:\\
\;\;\;\;-2 \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \left(J_m \cdot \mathsf{hypot}\left(1, \frac{0.5 \cdot \frac{U_m}{J_m}}{\cos \left(K \cdot 0.5\right)}\right)\right)\right)\\

\mathbf{else}:\\
\;\;\;\;-2 \cdot \left(U_m \cdot 0.5\right)\\


\end{array}
\end{array}
Derivation
    &prev;&pcontext;&pcontext2;&ctx;
  1. Add Preprocessing

Alternative 3: 88.8% accurate, 1.3× speedup?

\[\begin{array}{l} U_m = \left|U\right| \\ J_m = \left|J\right| \\ J_s = \mathsf{copysign}\left(1, J\right) \\ \begin{array}{l} t_0 := \cos \left(\frac{K}{2}\right)\\ J_s \cdot \begin{array}{l} \mathbf{if}\;U_m \leq 1.3 \cdot 10^{+256}:\\ \;\;\;\;-2 \cdot \left(t_0 \cdot \left(J_m \cdot \mathsf{hypot}\left(1, \frac{\frac{U_m}{2}}{J_m \cdot t_0}\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot \left(U_m \cdot 0.5\right)\\ \end{array} \end{array} \end{array} \]
U_m = (fabs.f64 U)
J_m = (fabs.f64 J)
J_s = (copysign.f64 1 J)
(FPCore (J_s J_m K U_m)
 :precision binary64
 (let* ((t_0 (cos (/ K 2.0))))
   (*
    J_s
    (if (<= U_m 1.3e+256)
      (* -2.0 (* t_0 (* J_m (hypot 1.0 (/ (/ U_m 2.0) (* J_m t_0))))))
      (* -2.0 (* U_m 0.5))))))
U_m = fabs(U);
J_m = fabs(J);
J_s = copysign(1.0, J);
double code(double J_s, double J_m, double K, double U_m) {
	double t_0 = cos((K / 2.0));
	double tmp;
	if (U_m <= 1.3e+256) {
		tmp = -2.0 * (t_0 * (J_m * hypot(1.0, ((U_m / 2.0) / (J_m * t_0)))));
	} else {
		tmp = -2.0 * (U_m * 0.5);
	}
	return J_s * tmp;
}
U_m = Math.abs(U);
J_m = Math.abs(J);
J_s = Math.copySign(1.0, J);
public static double code(double J_s, double J_m, double K, double U_m) {
	double t_0 = Math.cos((K / 2.0));
	double tmp;
	if (U_m <= 1.3e+256) {
		tmp = -2.0 * (t_0 * (J_m * Math.hypot(1.0, ((U_m / 2.0) / (J_m * t_0)))));
	} else {
		tmp = -2.0 * (U_m * 0.5);
	}
	return J_s * tmp;
}
U_m = math.fabs(U)
J_m = math.fabs(J)
J_s = math.copysign(1.0, J)
def code(J_s, J_m, K, U_m):
	t_0 = math.cos((K / 2.0))
	tmp = 0
	if U_m <= 1.3e+256:
		tmp = -2.0 * (t_0 * (J_m * math.hypot(1.0, ((U_m / 2.0) / (J_m * t_0)))))
	else:
		tmp = -2.0 * (U_m * 0.5)
	return J_s * tmp
U_m = abs(U)
J_m = abs(J)
J_s = copysign(1.0, J)
function code(J_s, J_m, K, U_m)
	t_0 = cos(Float64(K / 2.0))
	tmp = 0.0
	if (U_m <= 1.3e+256)
		tmp = Float64(-2.0 * Float64(t_0 * Float64(J_m * hypot(1.0, Float64(Float64(U_m / 2.0) / Float64(J_m * t_0))))));
	else
		tmp = Float64(-2.0 * Float64(U_m * 0.5));
	end
	return Float64(J_s * tmp)
end
U_m = abs(U);
J_m = abs(J);
J_s = sign(J) * abs(1.0);
function tmp_2 = code(J_s, J_m, K, U_m)
	t_0 = cos((K / 2.0));
	tmp = 0.0;
	if (U_m <= 1.3e+256)
		tmp = -2.0 * (t_0 * (J_m * hypot(1.0, ((U_m / 2.0) / (J_m * t_0)))));
	else
		tmp = -2.0 * (U_m * 0.5);
	end
	tmp_2 = J_s * tmp;
end
U_m = N[Abs[U], $MachinePrecision]
J_m = N[Abs[J], $MachinePrecision]
J_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[J$95$s_, J$95$m_, K_, U$95$m_] := Block[{t$95$0 = N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]}, N[(J$95$s * If[LessEqual[U$95$m, 1.3e+256], N[(-2.0 * N[(t$95$0 * N[(J$95$m * N[Sqrt[1.0 ^ 2 + N[(N[(U$95$m / 2.0), $MachinePrecision] / N[(J$95$m * t$95$0), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(-2.0 * N[(U$95$m * 0.5), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]]
\begin{array}{l}
U_m = \left|U\right|
\\
J_m = \left|J\right|
\\
J_s = \mathsf{copysign}\left(1, J\right)

\\
\begin{array}{l}
t_0 := \cos \left(\frac{K}{2}\right)\\
J_s \cdot \begin{array}{l}
\mathbf{if}\;U_m \leq 1.3 \cdot 10^{+256}:\\
\;\;\;\;-2 \cdot \left(t_0 \cdot \left(J_m \cdot \mathsf{hypot}\left(1, \frac{\frac{U_m}{2}}{J_m \cdot t_0}\right)\right)\right)\\

\mathbf{else}:\\
\;\;\;\;-2 \cdot \left(U_m \cdot 0.5\right)\\


\end{array}
\end{array}
\end{array}
Derivation
    &prev;&pcontext;&pcontext2;&ctx;
  1. Add Preprocessing

Alternative 4: 76.7% accurate, 1.9× speedup?

\[\begin{array}{l} U_m = \left|U\right| \\ J_m = \left|J\right| \\ J_s = \mathsf{copysign}\left(1, J\right) \\ J_s \cdot \begin{array}{l} \mathbf{if}\;J_m \leq 3.5 \cdot 10^{-86}:\\ \;\;\;\;-2 \cdot \left(U_m \cdot 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \left(J_m \cdot \mathsf{hypot}\left(1, 0.5 \cdot \frac{U_m}{J_m}\right)\right)\right)\\ \end{array} \end{array} \]
U_m = (fabs.f64 U)
J_m = (fabs.f64 J)
J_s = (copysign.f64 1 J)
(FPCore (J_s J_m K U_m)
 :precision binary64
 (*
  J_s
  (if (<= J_m 3.5e-86)
    (* -2.0 (* U_m 0.5))
    (* -2.0 (* (cos (/ K 2.0)) (* J_m (hypot 1.0 (* 0.5 (/ U_m J_m)))))))))
U_m = fabs(U);
J_m = fabs(J);
J_s = copysign(1.0, J);
double code(double J_s, double J_m, double K, double U_m) {
	double tmp;
	if (J_m <= 3.5e-86) {
		tmp = -2.0 * (U_m * 0.5);
	} else {
		tmp = -2.0 * (cos((K / 2.0)) * (J_m * hypot(1.0, (0.5 * (U_m / J_m)))));
	}
	return J_s * tmp;
}
U_m = Math.abs(U);
J_m = Math.abs(J);
J_s = Math.copySign(1.0, J);
public static double code(double J_s, double J_m, double K, double U_m) {
	double tmp;
	if (J_m <= 3.5e-86) {
		tmp = -2.0 * (U_m * 0.5);
	} else {
		tmp = -2.0 * (Math.cos((K / 2.0)) * (J_m * Math.hypot(1.0, (0.5 * (U_m / J_m)))));
	}
	return J_s * tmp;
}
U_m = math.fabs(U)
J_m = math.fabs(J)
J_s = math.copysign(1.0, J)
def code(J_s, J_m, K, U_m):
	tmp = 0
	if J_m <= 3.5e-86:
		tmp = -2.0 * (U_m * 0.5)
	else:
		tmp = -2.0 * (math.cos((K / 2.0)) * (J_m * math.hypot(1.0, (0.5 * (U_m / J_m)))))
	return J_s * tmp
U_m = abs(U)
J_m = abs(J)
J_s = copysign(1.0, J)
function code(J_s, J_m, K, U_m)
	tmp = 0.0
	if (J_m <= 3.5e-86)
		tmp = Float64(-2.0 * Float64(U_m * 0.5));
	else
		tmp = Float64(-2.0 * Float64(cos(Float64(K / 2.0)) * Float64(J_m * hypot(1.0, Float64(0.5 * Float64(U_m / J_m))))));
	end
	return Float64(J_s * tmp)
end
U_m = abs(U);
J_m = abs(J);
J_s = sign(J) * abs(1.0);
function tmp_2 = code(J_s, J_m, K, U_m)
	tmp = 0.0;
	if (J_m <= 3.5e-86)
		tmp = -2.0 * (U_m * 0.5);
	else
		tmp = -2.0 * (cos((K / 2.0)) * (J_m * hypot(1.0, (0.5 * (U_m / J_m)))));
	end
	tmp_2 = J_s * tmp;
end
U_m = N[Abs[U], $MachinePrecision]
J_m = N[Abs[J], $MachinePrecision]
J_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[J$95$s_, J$95$m_, K_, U$95$m_] := N[(J$95$s * If[LessEqual[J$95$m, 3.5e-86], N[(-2.0 * N[(U$95$m * 0.5), $MachinePrecision]), $MachinePrecision], N[(-2.0 * N[(N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision] * N[(J$95$m * N[Sqrt[1.0 ^ 2 + N[(0.5 * N[(U$95$m / J$95$m), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]
\begin{array}{l}
U_m = \left|U\right|
\\
J_m = \left|J\right|
\\
J_s = \mathsf{copysign}\left(1, J\right)

\\
J_s \cdot \begin{array}{l}
\mathbf{if}\;J_m \leq 3.5 \cdot 10^{-86}:\\
\;\;\;\;-2 \cdot \left(U_m \cdot 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;-2 \cdot \left(\cos \left(\frac{K}{2}\right) \cdot \left(J_m \cdot \mathsf{hypot}\left(1, 0.5 \cdot \frac{U_m}{J_m}\right)\right)\right)\\


\end{array}
\end{array}
Derivation
    &prev;&pcontext;&pcontext2;&ctx;
  1. Add Preprocessing

Alternative 5: 46.9% accurate, 3.7× speedup?

\[\begin{array}{l} U_m = \left|U\right| \\ J_m = \left|J\right| \\ J_s = \mathsf{copysign}\left(1, J\right) \\ \begin{array}{l} t_0 := -2 \cdot \left(J_m \cdot {1}^{0.3333333333333333}\right)\\ t_1 := -2 \cdot \left(U_m \cdot 0.5\right)\\ J_s \cdot \begin{array}{l} \mathbf{if}\;J_m \leq 6 \cdot 10^{-79}:\\ \;\;\;\;t_1\\ \mathbf{elif}\;J_m \leq 1.85 \cdot 10^{+58}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;J_m \leq 2.3 \cdot 10^{+103}:\\ \;\;\;\;t_1\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \end{array} \end{array} \]
U_m = (fabs.f64 U)
J_m = (fabs.f64 J)
J_s = (copysign.f64 1 J)
(FPCore (J_s J_m K U_m)
 :precision binary64
 (let* ((t_0 (* -2.0 (* J_m (pow 1.0 0.3333333333333333))))
        (t_1 (* -2.0 (* U_m 0.5))))
   (*
    J_s
    (if (<= J_m 6e-79)
      t_1
      (if (<= J_m 1.85e+58) t_0 (if (<= J_m 2.3e+103) t_1 t_0))))))
U_m = fabs(U);
J_m = fabs(J);
J_s = copysign(1.0, J);
double code(double J_s, double J_m, double K, double U_m) {
	double t_0 = -2.0 * (J_m * pow(1.0, 0.3333333333333333));
	double t_1 = -2.0 * (U_m * 0.5);
	double tmp;
	if (J_m <= 6e-79) {
		tmp = t_1;
	} else if (J_m <= 1.85e+58) {
		tmp = t_0;
	} else if (J_m <= 2.3e+103) {
		tmp = t_1;
	} else {
		tmp = t_0;
	}
	return J_s * tmp;
}
U_m = abs(U)
J_m = abs(J)
J_s = copysign(1.0d0, J)
real(8) function code(j_s, j_m, k, u_m)
    real(8), intent (in) :: j_s
    real(8), intent (in) :: j_m
    real(8), intent (in) :: k
    real(8), intent (in) :: u_m
    real(8) :: t_0
    real(8) :: t_1
    real(8) :: tmp
    t_0 = (-2.0d0) * (j_m * (1.0d0 ** 0.3333333333333333d0))
    t_1 = (-2.0d0) * (u_m * 0.5d0)
    if (j_m <= 6d-79) then
        tmp = t_1
    else if (j_m <= 1.85d+58) then
        tmp = t_0
    else if (j_m <= 2.3d+103) then
        tmp = t_1
    else
        tmp = t_0
    end if
    code = j_s * tmp
end function
U_m = Math.abs(U);
J_m = Math.abs(J);
J_s = Math.copySign(1.0, J);
public static double code(double J_s, double J_m, double K, double U_m) {
	double t_0 = -2.0 * (J_m * Math.pow(1.0, 0.3333333333333333));
	double t_1 = -2.0 * (U_m * 0.5);
	double tmp;
	if (J_m <= 6e-79) {
		tmp = t_1;
	} else if (J_m <= 1.85e+58) {
		tmp = t_0;
	} else if (J_m <= 2.3e+103) {
		tmp = t_1;
	} else {
		tmp = t_0;
	}
	return J_s * tmp;
}
U_m = math.fabs(U)
J_m = math.fabs(J)
J_s = math.copysign(1.0, J)
def code(J_s, J_m, K, U_m):
	t_0 = -2.0 * (J_m * math.pow(1.0, 0.3333333333333333))
	t_1 = -2.0 * (U_m * 0.5)
	tmp = 0
	if J_m <= 6e-79:
		tmp = t_1
	elif J_m <= 1.85e+58:
		tmp = t_0
	elif J_m <= 2.3e+103:
		tmp = t_1
	else:
		tmp = t_0
	return J_s * tmp
U_m = abs(U)
J_m = abs(J)
J_s = copysign(1.0, J)
function code(J_s, J_m, K, U_m)
	t_0 = Float64(-2.0 * Float64(J_m * (1.0 ^ 0.3333333333333333)))
	t_1 = Float64(-2.0 * Float64(U_m * 0.5))
	tmp = 0.0
	if (J_m <= 6e-79)
		tmp = t_1;
	elseif (J_m <= 1.85e+58)
		tmp = t_0;
	elseif (J_m <= 2.3e+103)
		tmp = t_1;
	else
		tmp = t_0;
	end
	return Float64(J_s * tmp)
end
U_m = abs(U);
J_m = abs(J);
J_s = sign(J) * abs(1.0);
function tmp_2 = code(J_s, J_m, K, U_m)
	t_0 = -2.0 * (J_m * (1.0 ^ 0.3333333333333333));
	t_1 = -2.0 * (U_m * 0.5);
	tmp = 0.0;
	if (J_m <= 6e-79)
		tmp = t_1;
	elseif (J_m <= 1.85e+58)
		tmp = t_0;
	elseif (J_m <= 2.3e+103)
		tmp = t_1;
	else
		tmp = t_0;
	end
	tmp_2 = J_s * tmp;
end
U_m = N[Abs[U], $MachinePrecision]
J_m = N[Abs[J], $MachinePrecision]
J_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[J$95$s_, J$95$m_, K_, U$95$m_] := Block[{t$95$0 = N[(-2.0 * N[(J$95$m * N[Power[1.0, 0.3333333333333333], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(-2.0 * N[(U$95$m * 0.5), $MachinePrecision]), $MachinePrecision]}, N[(J$95$s * If[LessEqual[J$95$m, 6e-79], t$95$1, If[LessEqual[J$95$m, 1.85e+58], t$95$0, If[LessEqual[J$95$m, 2.3e+103], t$95$1, t$95$0]]]), $MachinePrecision]]]
\begin{array}{l}
U_m = \left|U\right|
\\
J_m = \left|J\right|
\\
J_s = \mathsf{copysign}\left(1, J\right)

\\
\begin{array}{l}
t_0 := -2 \cdot \left(J_m \cdot {1}^{0.3333333333333333}\right)\\
t_1 := -2 \cdot \left(U_m \cdot 0.5\right)\\
J_s \cdot \begin{array}{l}
\mathbf{if}\;J_m \leq 6 \cdot 10^{-79}:\\
\;\;\;\;t_1\\

\mathbf{elif}\;J_m \leq 1.85 \cdot 10^{+58}:\\
\;\;\;\;t_0\\

\mathbf{elif}\;J_m \leq 2.3 \cdot 10^{+103}:\\
\;\;\;\;t_1\\

\mathbf{else}:\\
\;\;\;\;t_0\\


\end{array}
\end{array}
\end{array}
Derivation
    &prev;&pcontext;&pcontext2;&ctx;
  1. Add Preprocessing

Alternative 6: 65.3% accurate, 3.9× speedup?

\[\begin{array}{l} U_m = \left|U\right| \\ J_m = \left|J\right| \\ J_s = \mathsf{copysign}\left(1, J\right) \\ J_s \cdot \begin{array}{l} \mathbf{if}\;J_m \leq 1.95 \cdot 10^{-86}:\\ \;\;\;\;-2 \cdot \left(U_m \cdot 0.5\right)\\ \mathbf{else}:\\ \;\;\;\;-2 \cdot \left(J_m \cdot \cos \left(\frac{K}{2}\right)\right)\\ \end{array} \end{array} \]
U_m = (fabs.f64 U)
J_m = (fabs.f64 J)
J_s = (copysign.f64 1 J)
(FPCore (J_s J_m K U_m)
 :precision binary64
 (*
  J_s
  (if (<= J_m 1.95e-86)
    (* -2.0 (* U_m 0.5))
    (* -2.0 (* J_m (cos (/ K 2.0)))))))
U_m = fabs(U);
J_m = fabs(J);
J_s = copysign(1.0, J);
double code(double J_s, double J_m, double K, double U_m) {
	double tmp;
	if (J_m <= 1.95e-86) {
		tmp = -2.0 * (U_m * 0.5);
	} else {
		tmp = -2.0 * (J_m * cos((K / 2.0)));
	}
	return J_s * tmp;
}
U_m = abs(U)
J_m = abs(J)
J_s = copysign(1.0d0, J)
real(8) function code(j_s, j_m, k, u_m)
    real(8), intent (in) :: j_s
    real(8), intent (in) :: j_m
    real(8), intent (in) :: k
    real(8), intent (in) :: u_m
    real(8) :: tmp
    if (j_m <= 1.95d-86) then
        tmp = (-2.0d0) * (u_m * 0.5d0)
    else
        tmp = (-2.0d0) * (j_m * cos((k / 2.0d0)))
    end if
    code = j_s * tmp
end function
U_m = Math.abs(U);
J_m = Math.abs(J);
J_s = Math.copySign(1.0, J);
public static double code(double J_s, double J_m, double K, double U_m) {
	double tmp;
	if (J_m <= 1.95e-86) {
		tmp = -2.0 * (U_m * 0.5);
	} else {
		tmp = -2.0 * (J_m * Math.cos((K / 2.0)));
	}
	return J_s * tmp;
}
U_m = math.fabs(U)
J_m = math.fabs(J)
J_s = math.copysign(1.0, J)
def code(J_s, J_m, K, U_m):
	tmp = 0
	if J_m <= 1.95e-86:
		tmp = -2.0 * (U_m * 0.5)
	else:
		tmp = -2.0 * (J_m * math.cos((K / 2.0)))
	return J_s * tmp
U_m = abs(U)
J_m = abs(J)
J_s = copysign(1.0, J)
function code(J_s, J_m, K, U_m)
	tmp = 0.0
	if (J_m <= 1.95e-86)
		tmp = Float64(-2.0 * Float64(U_m * 0.5));
	else
		tmp = Float64(-2.0 * Float64(J_m * cos(Float64(K / 2.0))));
	end
	return Float64(J_s * tmp)
end
U_m = abs(U);
J_m = abs(J);
J_s = sign(J) * abs(1.0);
function tmp_2 = code(J_s, J_m, K, U_m)
	tmp = 0.0;
	if (J_m <= 1.95e-86)
		tmp = -2.0 * (U_m * 0.5);
	else
		tmp = -2.0 * (J_m * cos((K / 2.0)));
	end
	tmp_2 = J_s * tmp;
end
U_m = N[Abs[U], $MachinePrecision]
J_m = N[Abs[J], $MachinePrecision]
J_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[J$95$s_, J$95$m_, K_, U$95$m_] := N[(J$95$s * If[LessEqual[J$95$m, 1.95e-86], N[(-2.0 * N[(U$95$m * 0.5), $MachinePrecision]), $MachinePrecision], N[(-2.0 * N[(J$95$m * N[Cos[N[(K / 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]), $MachinePrecision]
\begin{array}{l}
U_m = \left|U\right|
\\
J_m = \left|J\right|
\\
J_s = \mathsf{copysign}\left(1, J\right)

\\
J_s \cdot \begin{array}{l}
\mathbf{if}\;J_m \leq 1.95 \cdot 10^{-86}:\\
\;\;\;\;-2 \cdot \left(U_m \cdot 0.5\right)\\

\mathbf{else}:\\
\;\;\;\;-2 \cdot \left(J_m \cdot \cos \left(\frac{K}{2}\right)\right)\\


\end{array}
\end{array}
Derivation
    &prev;&pcontext;&pcontext2;&ctx;
  1. Add Preprocessing

Alternative 7: 40.0% accurate, 84.0× speedup?

\[\begin{array}{l} U_m = \left|U\right| \\ J_m = \left|J\right| \\ J_s = \mathsf{copysign}\left(1, J\right) \\ J_s \cdot \left(-2 \cdot \left(U_m \cdot 0.5\right)\right) \end{array} \]
U_m = (fabs.f64 U)
J_m = (fabs.f64 J)
J_s = (copysign.f64 1 J)
(FPCore (J_s J_m K U_m) :precision binary64 (* J_s (* -2.0 (* U_m 0.5))))
U_m = fabs(U);
J_m = fabs(J);
J_s = copysign(1.0, J);
double code(double J_s, double J_m, double K, double U_m) {
	return J_s * (-2.0 * (U_m * 0.5));
}
U_m = abs(U)
J_m = abs(J)
J_s = copysign(1.0d0, J)
real(8) function code(j_s, j_m, k, u_m)
    real(8), intent (in) :: j_s
    real(8), intent (in) :: j_m
    real(8), intent (in) :: k
    real(8), intent (in) :: u_m
    code = j_s * ((-2.0d0) * (u_m * 0.5d0))
end function
U_m = Math.abs(U);
J_m = Math.abs(J);
J_s = Math.copySign(1.0, J);
public static double code(double J_s, double J_m, double K, double U_m) {
	return J_s * (-2.0 * (U_m * 0.5));
}
U_m = math.fabs(U)
J_m = math.fabs(J)
J_s = math.copysign(1.0, J)
def code(J_s, J_m, K, U_m):
	return J_s * (-2.0 * (U_m * 0.5))
U_m = abs(U)
J_m = abs(J)
J_s = copysign(1.0, J)
function code(J_s, J_m, K, U_m)
	return Float64(J_s * Float64(-2.0 * Float64(U_m * 0.5)))
end
U_m = abs(U);
J_m = abs(J);
J_s = sign(J) * abs(1.0);
function tmp = code(J_s, J_m, K, U_m)
	tmp = J_s * (-2.0 * (U_m * 0.5));
end
U_m = N[Abs[U], $MachinePrecision]
J_m = N[Abs[J], $MachinePrecision]
J_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[J]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[J$95$s_, J$95$m_, K_, U$95$m_] := N[(J$95$s * N[(-2.0 * N[(U$95$m * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
U_m = \left|U\right|
\\
J_m = \left|J\right|
\\
J_s = \mathsf{copysign}\left(1, J\right)

\\
J_s \cdot \left(-2 \cdot \left(U_m \cdot 0.5\right)\right)
\end{array}
Derivation
    &prev;&pcontext;&pcontext2;&ctx;
  1. Add Preprocessing

Reproduce

?
herbie shell --seed 2023348 
(FPCore (J K U)
  :name "Maksimov and Kolovsky, Equation (3)"
  :precision binary64
  (* (* (* -2.0 J) (cos (/ K 2.0))) (sqrt (+ 1.0 (pow (/ U (* (* 2.0 J) (cos (/ K 2.0)))) 2.0)))))