
(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:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(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}
(FPCore (l Om kx ky)
:precision binary64
(sqrt
(+
0.5
(*
0.5
(/
1.0
(pow
(sqrt (hypot 1.0 (* (* l (/ 2.0 Om)) (hypot (sin kx) (sin ky)))))
2.0))))))
double code(double l, double Om, double kx, double ky) {
return sqrt((0.5 + (0.5 * (1.0 / pow(sqrt(hypot(1.0, ((l * (2.0 / Om)) * hypot(sin(kx), sin(ky))))), 2.0)))));
}
public static double code(double l, double Om, double kx, double ky) {
return Math.sqrt((0.5 + (0.5 * (1.0 / Math.pow(Math.sqrt(Math.hypot(1.0, ((l * (2.0 / Om)) * Math.hypot(Math.sin(kx), Math.sin(ky))))), 2.0)))));
}
def code(l, Om, kx, ky): return math.sqrt((0.5 + (0.5 * (1.0 / math.pow(math.sqrt(math.hypot(1.0, ((l * (2.0 / Om)) * math.hypot(math.sin(kx), math.sin(ky))))), 2.0)))))
function code(l, Om, kx, ky) return sqrt(Float64(0.5 + Float64(0.5 * Float64(1.0 / (sqrt(hypot(1.0, Float64(Float64(l * Float64(2.0 / Om)) * hypot(sin(kx), sin(ky))))) ^ 2.0))))) end
function tmp = code(l, Om, kx, ky) tmp = sqrt((0.5 + (0.5 * (1.0 / (sqrt(hypot(1.0, ((l * (2.0 / Om)) * hypot(sin(kx), sin(ky))))) ^ 2.0))))); end
code[l_, Om_, kx_, ky_] := N[Sqrt[N[(0.5 + N[(0.5 * N[(1.0 / N[Power[N[Sqrt[N[Sqrt[1.0 ^ 2 + N[(N[(l * N[(2.0 / Om), $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[Sin[kx], $MachinePrecision] ^ 2 + N[Sin[ky], $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision]], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{0.5 + 0.5 \cdot \frac{1}{{\left(\sqrt{\mathsf{hypot}\left(1, \left(\ell \cdot \frac{2}{Om}\right) \cdot \mathsf{hypot}\left(\sin kx, \sin ky\right)\right)}\right)}^{2}}}
\end{array}
Initial program 97.7%
Simplified97.7%
add-sqr-sqrt97.7%
pow297.7%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (l Om kx ky)
:precision binary64
(sqrt
(+
0.5
(*
0.5
(/ 1.0 (hypot 1.0 (* (* l (/ 2.0 Om)) (hypot (sin kx) (sin ky)))))))))
double code(double l, double Om, double kx, double ky) {
return sqrt((0.5 + (0.5 * (1.0 / hypot(1.0, ((l * (2.0 / Om)) * hypot(sin(kx), sin(ky))))))));
}
public static double code(double l, double Om, double kx, double ky) {
return Math.sqrt((0.5 + (0.5 * (1.0 / Math.hypot(1.0, ((l * (2.0 / Om)) * Math.hypot(Math.sin(kx), Math.sin(ky))))))));
}
def code(l, Om, kx, ky): return math.sqrt((0.5 + (0.5 * (1.0 / math.hypot(1.0, ((l * (2.0 / Om)) * math.hypot(math.sin(kx), math.sin(ky))))))))
function code(l, Om, kx, ky) return sqrt(Float64(0.5 + Float64(0.5 * Float64(1.0 / hypot(1.0, Float64(Float64(l * Float64(2.0 / Om)) * hypot(sin(kx), sin(ky)))))))) end
function tmp = code(l, Om, kx, ky) tmp = sqrt((0.5 + (0.5 * (1.0 / hypot(1.0, ((l * (2.0 / Om)) * hypot(sin(kx), sin(ky)))))))); end
code[l_, Om_, kx_, ky_] := N[Sqrt[N[(0.5 + N[(0.5 * N[(1.0 / N[Sqrt[1.0 ^ 2 + N[(N[(l * N[(2.0 / Om), $MachinePrecision]), $MachinePrecision] * N[Sqrt[N[Sin[kx], $MachinePrecision] ^ 2 + N[Sin[ky], $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{0.5 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, \left(\ell \cdot \frac{2}{Om}\right) \cdot \mathsf{hypot}\left(\sin kx, \sin ky\right)\right)}}
\end{array}
Initial program 97.7%
Simplified97.7%
add-sqr-sqrt97.7%
hypot-1-def97.7%
sqrt-prod97.7%
unpow297.7%
sqrt-prod55.5%
add-sqr-sqrt97.9%
associate-/r/97.9%
*-commutative97.9%
unpow297.9%
unpow297.9%
hypot-def100.0%
Applied egg-rr100.0%
Final simplification100.0%
(FPCore (l Om kx ky) :precision binary64 (sqrt (+ 0.5 (* 0.5 (pow (sqrt (hypot 1.0 (* (* l (/ 2.0 Om)) (sin ky)))) -2.0)))))
double code(double l, double Om, double kx, double ky) {
return sqrt((0.5 + (0.5 * pow(sqrt(hypot(1.0, ((l * (2.0 / Om)) * sin(ky)))), -2.0))));
}
public static double code(double l, double Om, double kx, double ky) {
return Math.sqrt((0.5 + (0.5 * Math.pow(Math.sqrt(Math.hypot(1.0, ((l * (2.0 / Om)) * Math.sin(ky)))), -2.0))));
}
def code(l, Om, kx, ky): return math.sqrt((0.5 + (0.5 * math.pow(math.sqrt(math.hypot(1.0, ((l * (2.0 / Om)) * math.sin(ky)))), -2.0))))
function code(l, Om, kx, ky) return sqrt(Float64(0.5 + Float64(0.5 * (sqrt(hypot(1.0, Float64(Float64(l * Float64(2.0 / Om)) * sin(ky)))) ^ -2.0)))) end
function tmp = code(l, Om, kx, ky) tmp = sqrt((0.5 + (0.5 * (sqrt(hypot(1.0, ((l * (2.0 / Om)) * sin(ky)))) ^ -2.0)))); end
code[l_, Om_, kx_, ky_] := N[Sqrt[N[(0.5 + N[(0.5 * N[Power[N[Sqrt[N[Sqrt[1.0 ^ 2 + N[(N[(l * N[(2.0 / Om), $MachinePrecision]), $MachinePrecision] * N[Sin[ky], $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision]], $MachinePrecision], -2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{0.5 + 0.5 \cdot {\left(\sqrt{\mathsf{hypot}\left(1, \left(\ell \cdot \frac{2}{Om}\right) \cdot \sin ky\right)}\right)}^{-2}}
\end{array}
Initial program 97.7%
Simplified97.7%
add-sqr-sqrt97.7%
pow297.7%
Applied egg-rr100.0%
Taylor expanded in kx around 0 94.7%
pow-flip94.7%
metadata-eval94.7%
Applied egg-rr94.7%
Final simplification94.7%
(FPCore (l Om kx ky) :precision binary64 (sqrt (+ 0.5 (* 0.5 (/ 1.0 (hypot 1.0 (* (* l (/ 2.0 Om)) (sin ky))))))))
double code(double l, double Om, double kx, double ky) {
return sqrt((0.5 + (0.5 * (1.0 / hypot(1.0, ((l * (2.0 / Om)) * sin(ky)))))));
}
public static double code(double l, double Om, double kx, double ky) {
return Math.sqrt((0.5 + (0.5 * (1.0 / Math.hypot(1.0, ((l * (2.0 / Om)) * Math.sin(ky)))))));
}
def code(l, Om, kx, ky): return math.sqrt((0.5 + (0.5 * (1.0 / math.hypot(1.0, ((l * (2.0 / Om)) * math.sin(ky)))))))
function code(l, Om, kx, ky) return sqrt(Float64(0.5 + Float64(0.5 * Float64(1.0 / hypot(1.0, Float64(Float64(l * Float64(2.0 / Om)) * sin(ky))))))) end
function tmp = code(l, Om, kx, ky) tmp = sqrt((0.5 + (0.5 * (1.0 / hypot(1.0, ((l * (2.0 / Om)) * sin(ky))))))); end
code[l_, Om_, kx_, ky_] := N[Sqrt[N[(0.5 + N[(0.5 * N[(1.0 / N[Sqrt[1.0 ^ 2 + N[(N[(l * N[(2.0 / Om), $MachinePrecision]), $MachinePrecision] * N[Sin[ky], $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{0.5 + 0.5 \cdot \frac{1}{\mathsf{hypot}\left(1, \left(\ell \cdot \frac{2}{Om}\right) \cdot \sin ky\right)}}
\end{array}
Initial program 97.7%
Simplified97.7%
add-sqr-sqrt97.7%
hypot-1-def97.7%
sqrt-prod97.7%
unpow297.7%
sqrt-prod55.5%
add-sqr-sqrt97.9%
associate-/r/97.9%
*-commutative97.9%
unpow297.9%
unpow297.9%
hypot-def100.0%
Applied egg-rr100.0%
Taylor expanded in kx around 0 94.6%
Final simplification94.6%
(FPCore (l Om kx ky) :precision binary64 (sqrt (+ 0.5 (/ 0.5 (hypot 1.0 (* (/ 2.0 Om) (* l (sin kx))))))))
double code(double l, double Om, double kx, double ky) {
return sqrt((0.5 + (0.5 / hypot(1.0, ((2.0 / Om) * (l * sin(kx)))))));
}
public static double code(double l, double Om, double kx, double ky) {
return Math.sqrt((0.5 + (0.5 / Math.hypot(1.0, ((2.0 / Om) * (l * Math.sin(kx)))))));
}
def code(l, Om, kx, ky): return math.sqrt((0.5 + (0.5 / math.hypot(1.0, ((2.0 / Om) * (l * math.sin(kx)))))))
function code(l, Om, kx, ky) return sqrt(Float64(0.5 + Float64(0.5 / hypot(1.0, Float64(Float64(2.0 / Om) * Float64(l * sin(kx))))))) end
function tmp = code(l, Om, kx, ky) tmp = sqrt((0.5 + (0.5 / hypot(1.0, ((2.0 / Om) * (l * sin(kx))))))); end
code[l_, Om_, kx_, ky_] := N[Sqrt[N[(0.5 + N[(0.5 / N[Sqrt[1.0 ^ 2 + N[(N[(2.0 / Om), $MachinePrecision] * N[(l * N[Sin[kx], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, \frac{2}{Om} \cdot \left(\ell \cdot \sin kx\right)\right)}}
\end{array}
Initial program 97.7%
Simplified97.7%
Taylor expanded in ky around 0 74.7%
associate-/l*75.1%
associate-/r/74.9%
associate-*l*74.9%
*-commutative74.9%
unpow274.9%
unpow274.9%
times-frac87.1%
metadata-eval87.1%
swap-sqr87.1%
associate-*l/87.1%
associate-*r/87.1%
associate-*l/87.1%
associate-*r/87.1%
unpow287.1%
swap-sqr94.6%
*-commutative94.6%
*-commutative94.6%
Simplified94.6%
expm1-log1p-u94.0%
expm1-udef94.0%
associate-*l/94.0%
metadata-eval94.0%
associate-*r*94.0%
*-commutative94.0%
associate-*l*94.0%
Applied egg-rr94.0%
expm1-def94.0%
expm1-log1p94.6%
*-commutative94.6%
Simplified94.6%
Final simplification94.6%
(FPCore (l Om kx ky) :precision binary64 (if (<= Om 1e-55) (sqrt 0.5) 1.0))
double code(double l, double Om, double kx, double ky) {
double tmp;
if (Om <= 1e-55) {
tmp = sqrt(0.5);
} else {
tmp = 1.0;
}
return tmp;
}
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
real(8) :: tmp
if (om <= 1d-55) then
tmp = sqrt(0.5d0)
else
tmp = 1.0d0
end if
code = tmp
end function
public static double code(double l, double Om, double kx, double ky) {
double tmp;
if (Om <= 1e-55) {
tmp = Math.sqrt(0.5);
} else {
tmp = 1.0;
}
return tmp;
}
def code(l, Om, kx, ky): tmp = 0 if Om <= 1e-55: tmp = math.sqrt(0.5) else: tmp = 1.0 return tmp
function code(l, Om, kx, ky) tmp = 0.0 if (Om <= 1e-55) tmp = sqrt(0.5); else tmp = 1.0; end return tmp end
function tmp_2 = code(l, Om, kx, ky) tmp = 0.0; if (Om <= 1e-55) tmp = sqrt(0.5); else tmp = 1.0; end tmp_2 = tmp; end
code[l_, Om_, kx_, ky_] := If[LessEqual[Om, 1e-55], N[Sqrt[0.5], $MachinePrecision], 1.0]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;Om \leq 10^{-55}:\\
\;\;\;\;\sqrt{0.5}\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if Om < 9.99999999999999995e-56Initial program 96.7%
Simplified96.7%
Taylor expanded in ky around 0 69.5%
associate-/l*70.1%
associate-/r/69.8%
associate-*l*69.8%
*-commutative69.8%
unpow269.8%
unpow269.8%
times-frac84.0%
metadata-eval84.0%
swap-sqr84.0%
associate-*l/84.0%
associate-*r/84.0%
associate-*l/84.0%
associate-*r/84.0%
unpow284.0%
swap-sqr94.4%
*-commutative94.4%
*-commutative94.4%
Simplified94.4%
Taylor expanded in l around inf 62.8%
if 9.99999999999999995e-56 < Om Initial program 100.0%
Simplified100.0%
Taylor expanded in ky around 0 87.6%
associate-/l*87.6%
associate-/r/87.6%
associate-*l*87.6%
*-commutative87.6%
unpow287.6%
unpow287.6%
times-frac94.7%
metadata-eval94.7%
swap-sqr94.7%
associate-*l/94.7%
associate-*r/94.7%
associate-*l/94.7%
associate-*r/94.7%
unpow294.7%
swap-sqr95.0%
*-commutative95.0%
*-commutative95.0%
Simplified95.0%
expm1-log1p-u94.8%
expm1-udef94.8%
associate-*l/94.8%
metadata-eval94.8%
associate-*r*94.8%
*-commutative94.8%
associate-*l*94.8%
Applied egg-rr94.8%
expm1-def94.8%
expm1-log1p95.0%
*-commutative95.0%
Simplified95.0%
Taylor expanded in l around 0 83.6%
Final simplification68.7%
(FPCore (l Om kx ky) :precision binary64 (sqrt 0.5))
double code(double l, double Om, double kx, double ky) {
return sqrt(0.5);
}
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(0.5d0)
end function
public static double code(double l, double Om, double kx, double ky) {
return Math.sqrt(0.5);
}
def code(l, Om, kx, ky): return math.sqrt(0.5)
function code(l, Om, kx, ky) return sqrt(0.5) end
function tmp = code(l, Om, kx, ky) tmp = sqrt(0.5); end
code[l_, Om_, kx_, ky_] := N[Sqrt[0.5], $MachinePrecision]
\begin{array}{l}
\\
\sqrt{0.5}
\end{array}
Initial program 97.7%
Simplified97.7%
Taylor expanded in ky around 0 74.7%
associate-/l*75.1%
associate-/r/74.9%
associate-*l*74.9%
*-commutative74.9%
unpow274.9%
unpow274.9%
times-frac87.1%
metadata-eval87.1%
swap-sqr87.1%
associate-*l/87.1%
associate-*r/87.1%
associate-*l/87.1%
associate-*r/87.1%
unpow287.1%
swap-sqr94.6%
*-commutative94.6%
*-commutative94.6%
Simplified94.6%
Taylor expanded in l around inf 55.0%
Final simplification55.0%
herbie shell --seed 2023330
(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))))))))))