Toniolo and Linder, Equation (3a)

Percentage Accurate: 98.3% → 97.9%
Time: 8.3s
Alternatives: 4
Speedup: 0.8×

Specification

?
\[\begin{array}{l} \\ \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \end{array} \]
(FPCore (l Om kx ky)
 :precision binary64
 (sqrt
  (*
   (/ 1.0 2.0)
   (+
    1.0
    (/
     1.0
     (sqrt
      (+
       1.0
       (*
        (pow (/ (* 2.0 l) Om) 2.0)
        (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0))))))))))
double code(double l, double Om, double kx, double ky) {
	return sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + (pow(((2.0 * l) / Om), 2.0) * (pow(sin(kx), 2.0) + pow(sin(ky), 2.0)))))))));
}
real(8) function code(l, om, kx, ky)
    real(8), intent (in) :: l
    real(8), intent (in) :: om
    real(8), intent (in) :: kx
    real(8), intent (in) :: ky
    code = sqrt(((1.0d0 / 2.0d0) * (1.0d0 + (1.0d0 / sqrt((1.0d0 + ((((2.0d0 * l) / om) ** 2.0d0) * ((sin(kx) ** 2.0d0) + (sin(ky) ** 2.0d0)))))))))
end function
public static double code(double l, double Om, double kx, double ky) {
	return Math.sqrt(((1.0 / 2.0) * (1.0 + (1.0 / Math.sqrt((1.0 + (Math.pow(((2.0 * l) / Om), 2.0) * (Math.pow(Math.sin(kx), 2.0) + Math.pow(Math.sin(ky), 2.0)))))))));
}
def code(l, Om, kx, ky):
	return math.sqrt(((1.0 / 2.0) * (1.0 + (1.0 / math.sqrt((1.0 + (math.pow(((2.0 * l) / Om), 2.0) * (math.pow(math.sin(kx), 2.0) + math.pow(math.sin(ky), 2.0)))))))))
function code(l, Om, kx, ky)
	return sqrt(Float64(Float64(1.0 / 2.0) * Float64(1.0 + Float64(1.0 / sqrt(Float64(1.0 + Float64((Float64(Float64(2.0 * l) / Om) ^ 2.0) * Float64((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0)))))))))
end
function tmp = code(l, Om, kx, ky)
	tmp = sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + ((((2.0 * l) / Om) ^ 2.0) * ((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0)))))))));
end
code[l_, Om_, kx_, ky_] := N[Sqrt[N[(N[(1.0 / 2.0), $MachinePrecision] * N[(1.0 + N[(1.0 / N[Sqrt[N[(1.0 + N[(N[Power[N[(N[(2.0 * l), $MachinePrecision] / Om), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)}
\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 4 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: 98.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \end{array} \]
(FPCore (l Om kx ky)
 :precision binary64
 (sqrt
  (*
   (/ 1.0 2.0)
   (+
    1.0
    (/
     1.0
     (sqrt
      (+
       1.0
       (*
        (pow (/ (* 2.0 l) Om) 2.0)
        (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0))))))))))
double code(double l, double Om, double kx, double ky) {
	return sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + (pow(((2.0 * l) / Om), 2.0) * (pow(sin(kx), 2.0) + pow(sin(ky), 2.0)))))))));
}
real(8) function code(l, om, kx, ky)
    real(8), intent (in) :: l
    real(8), intent (in) :: om
    real(8), intent (in) :: kx
    real(8), intent (in) :: ky
    code = sqrt(((1.0d0 / 2.0d0) * (1.0d0 + (1.0d0 / sqrt((1.0d0 + ((((2.0d0 * l) / om) ** 2.0d0) * ((sin(kx) ** 2.0d0) + (sin(ky) ** 2.0d0)))))))))
end function
public static double code(double l, double Om, double kx, double ky) {
	return Math.sqrt(((1.0 / 2.0) * (1.0 + (1.0 / Math.sqrt((1.0 + (Math.pow(((2.0 * l) / Om), 2.0) * (Math.pow(Math.sin(kx), 2.0) + Math.pow(Math.sin(ky), 2.0)))))))));
}
def code(l, Om, kx, ky):
	return math.sqrt(((1.0 / 2.0) * (1.0 + (1.0 / math.sqrt((1.0 + (math.pow(((2.0 * l) / Om), 2.0) * (math.pow(math.sin(kx), 2.0) + math.pow(math.sin(ky), 2.0)))))))))
function code(l, Om, kx, ky)
	return sqrt(Float64(Float64(1.0 / 2.0) * Float64(1.0 + Float64(1.0 / sqrt(Float64(1.0 + Float64((Float64(Float64(2.0 * l) / Om) ^ 2.0) * Float64((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0)))))))))
end
function tmp = code(l, Om, kx, ky)
	tmp = sqrt(((1.0 / 2.0) * (1.0 + (1.0 / sqrt((1.0 + ((((2.0 * l) / Om) ^ 2.0) * ((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0)))))))));
end
code[l_, Om_, kx_, ky_] := N[Sqrt[N[(N[(1.0 / 2.0), $MachinePrecision] * N[(1.0 + N[(1.0 / N[Sqrt[N[(1.0 + N[(N[Power[N[(N[(2.0 * l), $MachinePrecision] / Om), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)}
\end{array}

Alternative 1: 97.9% accurate, 0.5× speedup?

\[\begin{array}{l} Om_m = \left|Om\right| \\ l_m = \left|\ell\right| \\ \begin{array}{l} \mathbf{if}\;{\left(\frac{2 \cdot l\_m}{Om\_m}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right) \leq 10^{-26}:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;\sqrt{{2}^{-1} \cdot \left(1 + {\left(\left(2 \cdot \frac{l\_m}{Om\_m}\right) \cdot \mathsf{hypot}\left(\sin ky, \sin kx\right)\right)}^{-1}\right)}\\ \end{array} \end{array} \]
Om_m = (fabs.f64 Om)
l_m = (fabs.f64 l)
(FPCore (l_m Om_m kx ky)
 :precision binary64
 (if (<=
      (*
       (pow (/ (* 2.0 l_m) Om_m) 2.0)
       (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0)))
      1e-26)
   1.0
   (sqrt
    (*
     (pow 2.0 -1.0)
     (+ 1.0 (pow (* (* 2.0 (/ l_m Om_m)) (hypot (sin ky) (sin kx))) -1.0))))))
Om_m = fabs(Om);
l_m = fabs(l);
double code(double l_m, double Om_m, double kx, double ky) {
	double tmp;
	if ((pow(((2.0 * l_m) / Om_m), 2.0) * (pow(sin(kx), 2.0) + pow(sin(ky), 2.0))) <= 1e-26) {
		tmp = 1.0;
	} else {
		tmp = sqrt((pow(2.0, -1.0) * (1.0 + pow(((2.0 * (l_m / Om_m)) * hypot(sin(ky), sin(kx))), -1.0))));
	}
	return tmp;
}
Om_m = Math.abs(Om);
l_m = Math.abs(l);
public static double code(double l_m, double Om_m, double kx, double ky) {
	double tmp;
	if ((Math.pow(((2.0 * l_m) / Om_m), 2.0) * (Math.pow(Math.sin(kx), 2.0) + Math.pow(Math.sin(ky), 2.0))) <= 1e-26) {
		tmp = 1.0;
	} else {
		tmp = Math.sqrt((Math.pow(2.0, -1.0) * (1.0 + Math.pow(((2.0 * (l_m / Om_m)) * Math.hypot(Math.sin(ky), Math.sin(kx))), -1.0))));
	}
	return tmp;
}
Om_m = math.fabs(Om)
l_m = math.fabs(l)
def code(l_m, Om_m, kx, ky):
	tmp = 0
	if (math.pow(((2.0 * l_m) / Om_m), 2.0) * (math.pow(math.sin(kx), 2.0) + math.pow(math.sin(ky), 2.0))) <= 1e-26:
		tmp = 1.0
	else:
		tmp = math.sqrt((math.pow(2.0, -1.0) * (1.0 + math.pow(((2.0 * (l_m / Om_m)) * math.hypot(math.sin(ky), math.sin(kx))), -1.0))))
	return tmp
Om_m = abs(Om)
l_m = abs(l)
function code(l_m, Om_m, kx, ky)
	tmp = 0.0
	if (Float64((Float64(Float64(2.0 * l_m) / Om_m) ^ 2.0) * Float64((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0))) <= 1e-26)
		tmp = 1.0;
	else
		tmp = sqrt(Float64((2.0 ^ -1.0) * Float64(1.0 + (Float64(Float64(2.0 * Float64(l_m / Om_m)) * hypot(sin(ky), sin(kx))) ^ -1.0))));
	end
	return tmp
end
Om_m = abs(Om);
l_m = abs(l);
function tmp_2 = code(l_m, Om_m, kx, ky)
	tmp = 0.0;
	if (((((2.0 * l_m) / Om_m) ^ 2.0) * ((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0))) <= 1e-26)
		tmp = 1.0;
	else
		tmp = sqrt(((2.0 ^ -1.0) * (1.0 + (((2.0 * (l_m / Om_m)) * hypot(sin(ky), sin(kx))) ^ -1.0))));
	end
	tmp_2 = tmp;
end
Om_m = N[Abs[Om], $MachinePrecision]
l_m = N[Abs[l], $MachinePrecision]
code[l$95$m_, Om$95$m_, kx_, ky_] := If[LessEqual[N[(N[Power[N[(N[(2.0 * l$95$m), $MachinePrecision] / Om$95$m), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1e-26], 1.0, N[Sqrt[N[(N[Power[2.0, -1.0], $MachinePrecision] * N[(1.0 + N[Power[N[(N[(2.0 * N[(l$95$m / Om$95$m), $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[Sin[ky], $MachinePrecision] ^ 2 + N[Sin[kx], $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision], -1.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]
\begin{array}{l}
Om_m = \left|Om\right|
\\
l_m = \left|\ell\right|

\\
\begin{array}{l}
\mathbf{if}\;{\left(\frac{2 \cdot l\_m}{Om\_m}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right) \leq 10^{-26}:\\
\;\;\;\;1\\

\mathbf{else}:\\
\;\;\;\;\sqrt{{2}^{-1} \cdot \left(1 + {\left(\left(2 \cdot \frac{l\_m}{Om\_m}\right) \cdot \mathsf{hypot}\left(\sin ky, \sin kx\right)\right)}^{-1}\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 (pow.f64 (/.f64 (*.f64 #s(literal 2 binary64) l) Om) #s(literal 2 binary64)) (+.f64 (pow.f64 (sin.f64 kx) #s(literal 2 binary64)) (pow.f64 (sin.f64 ky) #s(literal 2 binary64)))) < 1e-26

    1. Initial program 100.0%

      \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
    2. Add Preprocessing
    3. Taylor expanded in l around inf

      \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{2 \cdot \left(\frac{\ell}{Om} \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}\right)}}\right)} \]
    4. Step-by-step derivation
      1. associate-*r*N/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}}\right)} \]
      2. lower-*.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}}\right)} \]
      3. lower-*.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right)} \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}\right)} \]
      4. lower-/.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \color{blue}{\frac{\ell}{Om}}\right) \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}\right)} \]
      5. +-commutativeN/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{\color{blue}{{\sin ky}^{2} + {\sin kx}^{2}}}}\right)} \]
      6. unpow2N/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{\color{blue}{\sin ky \cdot \sin ky} + {\sin kx}^{2}}}\right)} \]
      7. unpow2N/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{\sin ky \cdot \sin ky + \color{blue}{\sin kx \cdot \sin kx}}}\right)} \]
      8. lower-hypot.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \color{blue}{\mathsf{hypot}\left(\sin ky, \sin kx\right)}}\right)} \]
      9. lower-sin.f64N/A

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \mathsf{hypot}\left(\color{blue}{\sin ky}, \sin kx\right)}\right)} \]
      10. lower-sin.f643.0

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \mathsf{hypot}\left(\sin ky, \color{blue}{\sin kx}\right)}\right)} \]
    5. Applied rewrites3.0%

      \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \mathsf{hypot}\left(\sin ky, \sin kx\right)}}\right)} \]
    6. Step-by-step derivation
      1. Applied rewrites2.7%

        \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \frac{\sqrt{\mathsf{fma}\left(1 - \cos \left(ky \cdot 2\right), 2, 2 \cdot \left(1 - \cos \left(kx \cdot 2\right)\right)\right)}}{\color{blue}{2}}}\right)} \]
      2. Applied rewrites2.7%

        \[\leadsto \sqrt{\color{blue}{\frac{0.5}{\sqrt{2 \cdot \left(\left(1 - \cos \left(ky + ky\right)\right) + \left(1 - \cos \left(kx + kx\right)\right)\right)} \cdot \left(0.5 \cdot \frac{\ell \cdot 2}{Om}\right)} + 0.5}} \]
      3. Taylor expanded in l around 0

        \[\leadsto \color{blue}{1} \]
      4. Step-by-step derivation
        1. Applied rewrites100.0%

          \[\leadsto \color{blue}{1} \]

        if 1e-26 < (*.f64 (pow.f64 (/.f64 (*.f64 #s(literal 2 binary64) l) Om) #s(literal 2 binary64)) (+.f64 (pow.f64 (sin.f64 kx) #s(literal 2 binary64)) (pow.f64 (sin.f64 ky) #s(literal 2 binary64))))

        1. Initial program 96.5%

          \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
        2. Add Preprocessing
        3. Taylor expanded in l around inf

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{2 \cdot \left(\frac{\ell}{Om} \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}\right)}}\right)} \]
        4. Step-by-step derivation
          1. associate-*r*N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}}\right)} \]
          2. lower-*.f64N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}}\right)} \]
          3. lower-*.f64N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right)} \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}\right)} \]
          4. lower-/.f64N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \color{blue}{\frac{\ell}{Om}}\right) \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}\right)} \]
          5. +-commutativeN/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{\color{blue}{{\sin ky}^{2} + {\sin kx}^{2}}}}\right)} \]
          6. unpow2N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{\color{blue}{\sin ky \cdot \sin ky} + {\sin kx}^{2}}}\right)} \]
          7. unpow2N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{\sin ky \cdot \sin ky + \color{blue}{\sin kx \cdot \sin kx}}}\right)} \]
          8. lower-hypot.f64N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \color{blue}{\mathsf{hypot}\left(\sin ky, \sin kx\right)}}\right)} \]
          9. lower-sin.f64N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \mathsf{hypot}\left(\color{blue}{\sin ky}, \sin kx\right)}\right)} \]
          10. lower-sin.f6499.2

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \mathsf{hypot}\left(\sin ky, \color{blue}{\sin kx}\right)}\right)} \]
        5. Applied rewrites99.2%

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \mathsf{hypot}\left(\sin ky, \sin kx\right)}}\right)} \]
      5. Recombined 2 regimes into one program.
      6. Final simplification99.7%

        \[\leadsto \begin{array}{l} \mathbf{if}\;{\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right) \leq 10^{-26}:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;\sqrt{{2}^{-1} \cdot \left(1 + {\left(\left(2 \cdot \frac{\ell}{Om}\right) \cdot \mathsf{hypot}\left(\sin ky, \sin kx\right)\right)}^{-1}\right)}\\ \end{array} \]
      7. Add Preprocessing

      Alternative 2: 98.3% accurate, 0.8× speedup?

      \[\begin{array}{l} Om_m = \left|Om\right| \\ l_m = \left|\ell\right| \\ \sqrt{{2}^{-1} \cdot \left(1 + {\left(\sqrt{1 + {\left(\frac{2 \cdot l\_m}{Om\_m}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}\right)}^{-1}\right)} \end{array} \]
      Om_m = (fabs.f64 Om)
      l_m = (fabs.f64 l)
      (FPCore (l_m Om_m kx ky)
       :precision binary64
       (sqrt
        (*
         (pow 2.0 -1.0)
         (+
          1.0
          (pow
           (sqrt
            (+
             1.0
             (*
              (pow (/ (* 2.0 l_m) Om_m) 2.0)
              (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0)))))
           -1.0)))))
      Om_m = fabs(Om);
      l_m = fabs(l);
      double code(double l_m, double Om_m, double kx, double ky) {
      	return sqrt((pow(2.0, -1.0) * (1.0 + pow(sqrt((1.0 + (pow(((2.0 * l_m) / Om_m), 2.0) * (pow(sin(kx), 2.0) + pow(sin(ky), 2.0))))), -1.0))));
      }
      
      Om_m = abs(om)
      l_m = abs(l)
      real(8) function code(l_m, om_m, kx, ky)
          real(8), intent (in) :: l_m
          real(8), intent (in) :: om_m
          real(8), intent (in) :: kx
          real(8), intent (in) :: ky
          code = sqrt(((2.0d0 ** (-1.0d0)) * (1.0d0 + (sqrt((1.0d0 + ((((2.0d0 * l_m) / om_m) ** 2.0d0) * ((sin(kx) ** 2.0d0) + (sin(ky) ** 2.0d0))))) ** (-1.0d0)))))
      end function
      
      Om_m = Math.abs(Om);
      l_m = Math.abs(l);
      public static double code(double l_m, double Om_m, double kx, double ky) {
      	return Math.sqrt((Math.pow(2.0, -1.0) * (1.0 + Math.pow(Math.sqrt((1.0 + (Math.pow(((2.0 * l_m) / Om_m), 2.0) * (Math.pow(Math.sin(kx), 2.0) + Math.pow(Math.sin(ky), 2.0))))), -1.0))));
      }
      
      Om_m = math.fabs(Om)
      l_m = math.fabs(l)
      def code(l_m, Om_m, kx, ky):
      	return math.sqrt((math.pow(2.0, -1.0) * (1.0 + math.pow(math.sqrt((1.0 + (math.pow(((2.0 * l_m) / Om_m), 2.0) * (math.pow(math.sin(kx), 2.0) + math.pow(math.sin(ky), 2.0))))), -1.0))))
      
      Om_m = abs(Om)
      l_m = abs(l)
      function code(l_m, Om_m, kx, ky)
      	return sqrt(Float64((2.0 ^ -1.0) * Float64(1.0 + (sqrt(Float64(1.0 + Float64((Float64(Float64(2.0 * l_m) / Om_m) ^ 2.0) * Float64((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0))))) ^ -1.0))))
      end
      
      Om_m = abs(Om);
      l_m = abs(l);
      function tmp = code(l_m, Om_m, kx, ky)
      	tmp = sqrt(((2.0 ^ -1.0) * (1.0 + (sqrt((1.0 + ((((2.0 * l_m) / Om_m) ^ 2.0) * ((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0))))) ^ -1.0))));
      end
      
      Om_m = N[Abs[Om], $MachinePrecision]
      l_m = N[Abs[l], $MachinePrecision]
      code[l$95$m_, Om$95$m_, kx_, ky_] := N[Sqrt[N[(N[Power[2.0, -1.0], $MachinePrecision] * N[(1.0 + N[Power[N[Sqrt[N[(1.0 + N[(N[Power[N[(N[(2.0 * l$95$m), $MachinePrecision] / Om$95$m), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision], -1.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
      
      \begin{array}{l}
      Om_m = \left|Om\right|
      \\
      l_m = \left|\ell\right|
      
      \\
      \sqrt{{2}^{-1} \cdot \left(1 + {\left(\sqrt{1 + {\left(\frac{2 \cdot l\_m}{Om\_m}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}\right)}^{-1}\right)}
      \end{array}
      
      Derivation
      1. Initial program 98.4%

        \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
      2. Add Preprocessing
      3. Final simplification98.4%

        \[\leadsto \sqrt{{2}^{-1} \cdot \left(1 + {\left(\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}\right)}^{-1}\right)} \]
      4. Add Preprocessing

      Alternative 3: 97.3% accurate, 1.1× speedup?

      \[\begin{array}{l} Om_m = \left|Om\right| \\ l_m = \left|\ell\right| \\ \begin{array}{l} \mathbf{if}\;{\left(\frac{2 \cdot l\_m}{Om\_m}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right) \leq 10^{-26}:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;\sqrt{0.5}\\ \end{array} \end{array} \]
      Om_m = (fabs.f64 Om)
      l_m = (fabs.f64 l)
      (FPCore (l_m Om_m kx ky)
       :precision binary64
       (if (<=
            (*
             (pow (/ (* 2.0 l_m) Om_m) 2.0)
             (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0)))
            1e-26)
         1.0
         (sqrt 0.5)))
      Om_m = fabs(Om);
      l_m = fabs(l);
      double code(double l_m, double Om_m, double kx, double ky) {
      	double tmp;
      	if ((pow(((2.0 * l_m) / Om_m), 2.0) * (pow(sin(kx), 2.0) + pow(sin(ky), 2.0))) <= 1e-26) {
      		tmp = 1.0;
      	} else {
      		tmp = sqrt(0.5);
      	}
      	return tmp;
      }
      
      Om_m = abs(om)
      l_m = abs(l)
      real(8) function code(l_m, om_m, kx, ky)
          real(8), intent (in) :: l_m
          real(8), intent (in) :: om_m
          real(8), intent (in) :: kx
          real(8), intent (in) :: ky
          real(8) :: tmp
          if (((((2.0d0 * l_m) / om_m) ** 2.0d0) * ((sin(kx) ** 2.0d0) + (sin(ky) ** 2.0d0))) <= 1d-26) then
              tmp = 1.0d0
          else
              tmp = sqrt(0.5d0)
          end if
          code = tmp
      end function
      
      Om_m = Math.abs(Om);
      l_m = Math.abs(l);
      public static double code(double l_m, double Om_m, double kx, double ky) {
      	double tmp;
      	if ((Math.pow(((2.0 * l_m) / Om_m), 2.0) * (Math.pow(Math.sin(kx), 2.0) + Math.pow(Math.sin(ky), 2.0))) <= 1e-26) {
      		tmp = 1.0;
      	} else {
      		tmp = Math.sqrt(0.5);
      	}
      	return tmp;
      }
      
      Om_m = math.fabs(Om)
      l_m = math.fabs(l)
      def code(l_m, Om_m, kx, ky):
      	tmp = 0
      	if (math.pow(((2.0 * l_m) / Om_m), 2.0) * (math.pow(math.sin(kx), 2.0) + math.pow(math.sin(ky), 2.0))) <= 1e-26:
      		tmp = 1.0
      	else:
      		tmp = math.sqrt(0.5)
      	return tmp
      
      Om_m = abs(Om)
      l_m = abs(l)
      function code(l_m, Om_m, kx, ky)
      	tmp = 0.0
      	if (Float64((Float64(Float64(2.0 * l_m) / Om_m) ^ 2.0) * Float64((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0))) <= 1e-26)
      		tmp = 1.0;
      	else
      		tmp = sqrt(0.5);
      	end
      	return tmp
      end
      
      Om_m = abs(Om);
      l_m = abs(l);
      function tmp_2 = code(l_m, Om_m, kx, ky)
      	tmp = 0.0;
      	if (((((2.0 * l_m) / Om_m) ^ 2.0) * ((sin(kx) ^ 2.0) + (sin(ky) ^ 2.0))) <= 1e-26)
      		tmp = 1.0;
      	else
      		tmp = sqrt(0.5);
      	end
      	tmp_2 = tmp;
      end
      
      Om_m = N[Abs[Om], $MachinePrecision]
      l_m = N[Abs[l], $MachinePrecision]
      code[l$95$m_, Om$95$m_, kx_, ky_] := If[LessEqual[N[(N[Power[N[(N[(2.0 * l$95$m), $MachinePrecision] / Om$95$m), $MachinePrecision], 2.0], $MachinePrecision] * N[(N[Power[N[Sin[kx], $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[Sin[ky], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1e-26], 1.0, N[Sqrt[0.5], $MachinePrecision]]
      
      \begin{array}{l}
      Om_m = \left|Om\right|
      \\
      l_m = \left|\ell\right|
      
      \\
      \begin{array}{l}
      \mathbf{if}\;{\left(\frac{2 \cdot l\_m}{Om\_m}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right) \leq 10^{-26}:\\
      \;\;\;\;1\\
      
      \mathbf{else}:\\
      \;\;\;\;\sqrt{0.5}\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (*.f64 (pow.f64 (/.f64 (*.f64 #s(literal 2 binary64) l) Om) #s(literal 2 binary64)) (+.f64 (pow.f64 (sin.f64 kx) #s(literal 2 binary64)) (pow.f64 (sin.f64 ky) #s(literal 2 binary64)))) < 1e-26

        1. Initial program 100.0%

          \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
        2. Add Preprocessing
        3. Taylor expanded in l around inf

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{2 \cdot \left(\frac{\ell}{Om} \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}\right)}}\right)} \]
        4. Step-by-step derivation
          1. associate-*r*N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}}\right)} \]
          2. lower-*.f64N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}}\right)} \]
          3. lower-*.f64N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right)} \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}\right)} \]
          4. lower-/.f64N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \color{blue}{\frac{\ell}{Om}}\right) \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}\right)} \]
          5. +-commutativeN/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{\color{blue}{{\sin ky}^{2} + {\sin kx}^{2}}}}\right)} \]
          6. unpow2N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{\color{blue}{\sin ky \cdot \sin ky} + {\sin kx}^{2}}}\right)} \]
          7. unpow2N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{\sin ky \cdot \sin ky + \color{blue}{\sin kx \cdot \sin kx}}}\right)} \]
          8. lower-hypot.f64N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \color{blue}{\mathsf{hypot}\left(\sin ky, \sin kx\right)}}\right)} \]
          9. lower-sin.f64N/A

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \mathsf{hypot}\left(\color{blue}{\sin ky}, \sin kx\right)}\right)} \]
          10. lower-sin.f643.0

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \mathsf{hypot}\left(\sin ky, \color{blue}{\sin kx}\right)}\right)} \]
        5. Applied rewrites3.0%

          \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \mathsf{hypot}\left(\sin ky, \sin kx\right)}}\right)} \]
        6. Step-by-step derivation
          1. Applied rewrites2.7%

            \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \frac{\sqrt{\mathsf{fma}\left(1 - \cos \left(ky \cdot 2\right), 2, 2 \cdot \left(1 - \cos \left(kx \cdot 2\right)\right)\right)}}{\color{blue}{2}}}\right)} \]
          2. Applied rewrites2.7%

            \[\leadsto \sqrt{\color{blue}{\frac{0.5}{\sqrt{2 \cdot \left(\left(1 - \cos \left(ky + ky\right)\right) + \left(1 - \cos \left(kx + kx\right)\right)\right)} \cdot \left(0.5 \cdot \frac{\ell \cdot 2}{Om}\right)} + 0.5}} \]
          3. Taylor expanded in l around 0

            \[\leadsto \color{blue}{1} \]
          4. Step-by-step derivation
            1. Applied rewrites100.0%

              \[\leadsto \color{blue}{1} \]

            if 1e-26 < (*.f64 (pow.f64 (/.f64 (*.f64 #s(literal 2 binary64) l) Om) #s(literal 2 binary64)) (+.f64 (pow.f64 (sin.f64 kx) #s(literal 2 binary64)) (pow.f64 (sin.f64 ky) #s(literal 2 binary64))))

            1. Initial program 96.5%

              \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in l around inf

              \[\leadsto \sqrt{\color{blue}{\frac{1}{2}}} \]
            4. Step-by-step derivation
              1. Applied rewrites99.1%

                \[\leadsto \sqrt{\color{blue}{0.5}} \]
            5. Recombined 2 regimes into one program.
            6. Add Preprocessing

            Alternative 4: 62.2% accurate, 581.0× speedup?

            \[\begin{array}{l} Om_m = \left|Om\right| \\ l_m = \left|\ell\right| \\ 1 \end{array} \]
            Om_m = (fabs.f64 Om)
            l_m = (fabs.f64 l)
            (FPCore (l_m Om_m kx ky) :precision binary64 1.0)
            Om_m = fabs(Om);
            l_m = fabs(l);
            double code(double l_m, double Om_m, double kx, double ky) {
            	return 1.0;
            }
            
            Om_m = abs(om)
            l_m = abs(l)
            real(8) function code(l_m, om_m, kx, ky)
                real(8), intent (in) :: l_m
                real(8), intent (in) :: om_m
                real(8), intent (in) :: kx
                real(8), intent (in) :: ky
                code = 1.0d0
            end function
            
            Om_m = Math.abs(Om);
            l_m = Math.abs(l);
            public static double code(double l_m, double Om_m, double kx, double ky) {
            	return 1.0;
            }
            
            Om_m = math.fabs(Om)
            l_m = math.fabs(l)
            def code(l_m, Om_m, kx, ky):
            	return 1.0
            
            Om_m = abs(Om)
            l_m = abs(l)
            function code(l_m, Om_m, kx, ky)
            	return 1.0
            end
            
            Om_m = abs(Om);
            l_m = abs(l);
            function tmp = code(l_m, Om_m, kx, ky)
            	tmp = 1.0;
            end
            
            Om_m = N[Abs[Om], $MachinePrecision]
            l_m = N[Abs[l], $MachinePrecision]
            code[l$95$m_, Om$95$m_, kx_, ky_] := 1.0
            
            \begin{array}{l}
            Om_m = \left|Om\right|
            \\
            l_m = \left|\ell\right|
            
            \\
            1
            \end{array}
            
            Derivation
            1. Initial program 98.4%

              \[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\sin kx}^{2} + {\sin ky}^{2}\right)}}\right)} \]
            2. Add Preprocessing
            3. Taylor expanded in l around inf

              \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{2 \cdot \left(\frac{\ell}{Om} \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}\right)}}\right)} \]
            4. Step-by-step derivation
              1. associate-*r*N/A

                \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}}\right)} \]
              2. lower-*.f64N/A

                \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}}\right)} \]
              3. lower-*.f64N/A

                \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right)} \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}\right)} \]
              4. lower-/.f64N/A

                \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \color{blue}{\frac{\ell}{Om}}\right) \cdot \sqrt{{\sin kx}^{2} + {\sin ky}^{2}}}\right)} \]
              5. +-commutativeN/A

                \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{\color{blue}{{\sin ky}^{2} + {\sin kx}^{2}}}}\right)} \]
              6. unpow2N/A

                \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{\color{blue}{\sin ky \cdot \sin ky} + {\sin kx}^{2}}}\right)} \]
              7. unpow2N/A

                \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \sqrt{\sin ky \cdot \sin ky + \color{blue}{\sin kx \cdot \sin kx}}}\right)} \]
              8. lower-hypot.f64N/A

                \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \color{blue}{\mathsf{hypot}\left(\sin ky, \sin kx\right)}}\right)} \]
              9. lower-sin.f64N/A

                \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \mathsf{hypot}\left(\color{blue}{\sin ky}, \sin kx\right)}\right)} \]
              10. lower-sin.f6445.9

                \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \mathsf{hypot}\left(\sin ky, \color{blue}{\sin kx}\right)}\right)} \]
            5. Applied rewrites45.9%

              \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\color{blue}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \mathsf{hypot}\left(\sin ky, \sin kx\right)}}\right)} \]
            6. Step-by-step derivation
              1. Applied rewrites37.5%

                \[\leadsto \sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\left(2 \cdot \frac{\ell}{Om}\right) \cdot \frac{\sqrt{\mathsf{fma}\left(1 - \cos \left(ky \cdot 2\right), 2, 2 \cdot \left(1 - \cos \left(kx \cdot 2\right)\right)\right)}}{\color{blue}{2}}}\right)} \]
              2. Applied rewrites37.5%

                \[\leadsto \sqrt{\color{blue}{\frac{0.5}{\sqrt{2 \cdot \left(\left(1 - \cos \left(ky + ky\right)\right) + \left(1 - \cos \left(kx + kx\right)\right)\right)} \cdot \left(0.5 \cdot \frac{\ell \cdot 2}{Om}\right)} + 0.5}} \]
              3. Taylor expanded in l around 0

                \[\leadsto \color{blue}{1} \]
              4. Step-by-step derivation
                1. Applied rewrites64.7%

                  \[\leadsto \color{blue}{1} \]
                2. Add Preprocessing

                Reproduce

                ?
                herbie shell --seed 2024318 
                (FPCore (l Om kx ky)
                  :name "Toniolo and Linder, Equation (3a)"
                  :precision binary64
                  (sqrt (* (/ 1.0 2.0) (+ 1.0 (/ 1.0 (sqrt (+ 1.0 (* (pow (/ (* 2.0 l) Om) 2.0) (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0))))))))))