
(FPCore (u0 u1 alphax alphay)
:precision binary32
(let* ((t_0
(atan (* (/ alphay alphax) (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI))))))
(t_1 (sin t_0))
(t_2 (cos t_0)))
(/
1.0
(sqrt
(+
1.0
(/
(*
(/
1.0
(+
(/ (* t_2 t_2) (* alphax alphax))
(/ (* t_1 t_1) (* alphay alphay))))
u0)
(- 1.0 u0)))))))
float code(float u0, float u1, float alphax, float alphay) {
float t_0 = atanf(((alphay / alphax) * tanf((((2.0f * ((float) M_PI)) * u1) + (0.5f * ((float) M_PI))))));
float t_1 = sinf(t_0);
float t_2 = cosf(t_0);
return 1.0f / sqrtf((1.0f + (((1.0f / (((t_2 * t_2) / (alphax * alphax)) + ((t_1 * t_1) / (alphay * alphay)))) * u0) / (1.0f - u0))));
}
function code(u0, u1, alphax, alphay) t_0 = atan(Float32(Float32(alphay / alphax) * tan(Float32(Float32(Float32(Float32(2.0) * Float32(pi)) * u1) + Float32(Float32(0.5) * Float32(pi)))))) t_1 = sin(t_0) t_2 = cos(t_0) return Float32(Float32(1.0) / sqrt(Float32(Float32(1.0) + Float32(Float32(Float32(Float32(1.0) / Float32(Float32(Float32(t_2 * t_2) / Float32(alphax * alphax)) + Float32(Float32(t_1 * t_1) / Float32(alphay * alphay)))) * u0) / Float32(Float32(1.0) - u0))))) end
function tmp = code(u0, u1, alphax, alphay) t_0 = atan(((alphay / alphax) * tan((((single(2.0) * single(pi)) * u1) + (single(0.5) * single(pi)))))); t_1 = sin(t_0); t_2 = cos(t_0); tmp = single(1.0) / sqrt((single(1.0) + (((single(1.0) / (((t_2 * t_2) / (alphax * alphax)) + ((t_1 * t_1) / (alphay * alphay)))) * u0) / (single(1.0) - u0)))); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)\\
t_1 := \sin t\_0\\
t_2 := \cos t\_0\\
\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{t\_2 \cdot t\_2}{alphax \cdot alphax} + \frac{t\_1 \cdot t\_1}{alphay \cdot alphay}} \cdot u0}{1 - u0}}}
\end{array}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 10 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (u0 u1 alphax alphay)
:precision binary32
(let* ((t_0
(atan (* (/ alphay alphax) (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI))))))
(t_1 (sin t_0))
(t_2 (cos t_0)))
(/
1.0
(sqrt
(+
1.0
(/
(*
(/
1.0
(+
(/ (* t_2 t_2) (* alphax alphax))
(/ (* t_1 t_1) (* alphay alphay))))
u0)
(- 1.0 u0)))))))
float code(float u0, float u1, float alphax, float alphay) {
float t_0 = atanf(((alphay / alphax) * tanf((((2.0f * ((float) M_PI)) * u1) + (0.5f * ((float) M_PI))))));
float t_1 = sinf(t_0);
float t_2 = cosf(t_0);
return 1.0f / sqrtf((1.0f + (((1.0f / (((t_2 * t_2) / (alphax * alphax)) + ((t_1 * t_1) / (alphay * alphay)))) * u0) / (1.0f - u0))));
}
function code(u0, u1, alphax, alphay) t_0 = atan(Float32(Float32(alphay / alphax) * tan(Float32(Float32(Float32(Float32(2.0) * Float32(pi)) * u1) + Float32(Float32(0.5) * Float32(pi)))))) t_1 = sin(t_0) t_2 = cos(t_0) return Float32(Float32(1.0) / sqrt(Float32(Float32(1.0) + Float32(Float32(Float32(Float32(1.0) / Float32(Float32(Float32(t_2 * t_2) / Float32(alphax * alphax)) + Float32(Float32(t_1 * t_1) / Float32(alphay * alphay)))) * u0) / Float32(Float32(1.0) - u0))))) end
function tmp = code(u0, u1, alphax, alphay) t_0 = atan(((alphay / alphax) * tan((((single(2.0) * single(pi)) * u1) + (single(0.5) * single(pi)))))); t_1 = sin(t_0); t_2 = cos(t_0); tmp = single(1.0) / sqrt((single(1.0) + (((single(1.0) / (((t_2 * t_2) / (alphax * alphax)) + ((t_1 * t_1) / (alphay * alphay)))) * u0) / (single(1.0) - u0)))); end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)\\
t_1 := \sin t\_0\\
t_2 := \cos t\_0\\
\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{t\_2 \cdot t\_2}{alphax \cdot alphax} + \frac{t\_1 \cdot t\_1}{alphay \cdot alphay}} \cdot u0}{1 - u0}}}
\end{array}
\end{array}
(FPCore (u0 u1 alphax alphay)
:precision binary32
(let* ((t_0 (tan (* PI (fma 2.0 u1 0.5)))))
(exp
(*
(log1p
(/
u0
(*
(- 1.0 u0)
(+
(/ 1.0 (fma alphax alphax (pow (* t_0 alphay) 2.0)))
(/
(+ 1.0 (/ 1.0 (- -1.0 (pow (* t_0 (/ alphay alphax)) 2.0))))
(* alphay alphay))))))
-0.5))))
float code(float u0, float u1, float alphax, float alphay) {
float t_0 = tanf((((float) M_PI) * fmaf(2.0f, u1, 0.5f)));
return expf((log1pf((u0 / ((1.0f - u0) * ((1.0f / fmaf(alphax, alphax, powf((t_0 * alphay), 2.0f))) + ((1.0f + (1.0f / (-1.0f - powf((t_0 * (alphay / alphax)), 2.0f)))) / (alphay * alphay)))))) * -0.5f));
}
function code(u0, u1, alphax, alphay) t_0 = tan(Float32(Float32(pi) * fma(Float32(2.0), u1, Float32(0.5)))) return exp(Float32(log1p(Float32(u0 / Float32(Float32(Float32(1.0) - u0) * Float32(Float32(Float32(1.0) / fma(alphax, alphax, (Float32(t_0 * alphay) ^ Float32(2.0)))) + Float32(Float32(Float32(1.0) + Float32(Float32(1.0) / Float32(Float32(-1.0) - (Float32(t_0 * Float32(alphay / alphax)) ^ Float32(2.0))))) / Float32(alphay * alphay)))))) * Float32(-0.5))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\\
e^{\mathsf{log1p}\left(\frac{u0}{\left(1 - u0\right) \cdot \left(\frac{1}{\mathsf{fma}\left(alphax, alphax, {\left(t\_0 \cdot alphay\right)}^{2}\right)} + \frac{1 + \frac{1}{-1 - {\left(t\_0 \cdot \frac{alphay}{alphax}\right)}^{2}}}{alphay \cdot alphay}\right)}\right) \cdot -0.5}
\end{array}
\end{array}
Initial program 99.2%
Applied rewrites99.3%
Applied rewrites100.0%
lift-*.f32N/A
lift-/.f32N/A
lift-PI.f32N/A
lift-fma.f32N/A
lift-*.f32N/A
lift-tan.f32N/A
lift-*.f32N/A
unpow1N/A
metadata-evalN/A
metadata-evalN/A
unpow1N/A
lift-pow.f32N/A
Applied rewrites100.0%
lift-PI.f32N/A
lift-fma.f32N/A
lift-*.f32N/A
lift-tan.f32N/A
associate-*r/N/A
associate-*l/N/A
lift-/.f32N/A
lift-/.f32N/A
associate-*l/N/A
associate-*r/N/A
lift-/.f32N/A
associate-*l*N/A
*-commutativeN/A
lower-*.f32N/A
Applied rewrites100.0%
Final simplification100.0%
(FPCore (u0 u1 alphax alphay)
:precision binary32
(let* ((t_0 (* alphay (/ (tan (* PI (fma 2.0 u1 0.5))) alphax))))
(pow
(+
1.0
(/
u0
(*
(- 1.0 u0)
(+
(/ 1.0 (fma alphax alphax (pow (* alphax t_0) 2.0)))
(/ (+ 1.0 (/ -1.0 (+ 1.0 (pow t_0 2.0)))) (* alphay alphay))))))
-0.5)))
float code(float u0, float u1, float alphax, float alphay) {
float t_0 = alphay * (tanf((((float) M_PI) * fmaf(2.0f, u1, 0.5f))) / alphax);
return powf((1.0f + (u0 / ((1.0f - u0) * ((1.0f / fmaf(alphax, alphax, powf((alphax * t_0), 2.0f))) + ((1.0f + (-1.0f / (1.0f + powf(t_0, 2.0f)))) / (alphay * alphay)))))), -0.5f);
}
function code(u0, u1, alphax, alphay) t_0 = Float32(alphay * Float32(tan(Float32(Float32(pi) * fma(Float32(2.0), u1, Float32(0.5)))) / alphax)) return Float32(Float32(1.0) + Float32(u0 / Float32(Float32(Float32(1.0) - u0) * Float32(Float32(Float32(1.0) / fma(alphax, alphax, (Float32(alphax * t_0) ^ Float32(2.0)))) + Float32(Float32(Float32(1.0) + Float32(Float32(-1.0) / Float32(Float32(1.0) + (t_0 ^ Float32(2.0))))) / Float32(alphay * alphay)))))) ^ Float32(-0.5) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := alphay \cdot \frac{\tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)}{alphax}\\
{\left(1 + \frac{u0}{\left(1 - u0\right) \cdot \left(\frac{1}{\mathsf{fma}\left(alphax, alphax, {\left(alphax \cdot t\_0\right)}^{2}\right)} + \frac{1 + \frac{-1}{1 + {t\_0}^{2}}}{alphay \cdot alphay}\right)}\right)}^{-0.5}
\end{array}
\end{array}
Initial program 99.2%
Applied rewrites99.3%
Applied rewrites100.0%
Applied rewrites99.9%
Final simplification99.9%
(FPCore (u0 u1 alphax alphay)
:precision binary32
(let* ((t_0 (pow (* (tan (* PI (fma 2.0 u1 0.5))) (/ alphay alphax)) 2.0)))
(/
1.0
(sqrt
(+
1.0
(/
u0
(*
(- 1.0 u0)
(+
(/ (+ 1.0 (/ 1.0 (- -1.0 t_0))) (* alphay alphay))
(/ 1.0 (* (+ 1.0 t_0) (* alphax alphax)))))))))))
float code(float u0, float u1, float alphax, float alphay) {
float t_0 = powf((tanf((((float) M_PI) * fmaf(2.0f, u1, 0.5f))) * (alphay / alphax)), 2.0f);
return 1.0f / sqrtf((1.0f + (u0 / ((1.0f - u0) * (((1.0f + (1.0f / (-1.0f - t_0))) / (alphay * alphay)) + (1.0f / ((1.0f + t_0) * (alphax * alphax))))))));
}
function code(u0, u1, alphax, alphay) t_0 = Float32(tan(Float32(Float32(pi) * fma(Float32(2.0), u1, Float32(0.5)))) * Float32(alphay / alphax)) ^ Float32(2.0) return Float32(Float32(1.0) / sqrt(Float32(Float32(1.0) + Float32(u0 / Float32(Float32(Float32(1.0) - u0) * Float32(Float32(Float32(Float32(1.0) + Float32(Float32(1.0) / Float32(Float32(-1.0) - t_0))) / Float32(alphay * alphay)) + Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + t_0) * Float32(alphax * alphax))))))))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := {\left(\tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right) \cdot \frac{alphay}{alphax}\right)}^{2}\\
\frac{1}{\sqrt{1 + \frac{u0}{\left(1 - u0\right) \cdot \left(\frac{1 + \frac{1}{-1 - t\_0}}{alphay \cdot alphay} + \frac{1}{\left(1 + t\_0\right) \cdot \left(alphax \cdot alphax\right)}\right)}}}
\end{array}
\end{array}
Initial program 99.2%
Applied rewrites99.3%
Applied rewrites99.3%
Final simplification99.3%
(FPCore (u0 u1 alphax alphay)
:precision binary32
(exp
(*
-0.5
(log1p
(/
u0
(*
(- 1.0 u0)
(+
(/
1.0
(*
(+ 1.0 (pow (* (tan (* PI (fma 2.0 u1 0.5))) (/ alphay alphax)) 2.0))
(* alphax alphax)))
(/ 1.0 (* alphay alphay)))))))))
float code(float u0, float u1, float alphax, float alphay) {
return expf((-0.5f * log1pf((u0 / ((1.0f - u0) * ((1.0f / ((1.0f + powf((tanf((((float) M_PI) * fmaf(2.0f, u1, 0.5f))) * (alphay / alphax)), 2.0f)) * (alphax * alphax))) + (1.0f / (alphay * alphay))))))));
}
function code(u0, u1, alphax, alphay) return exp(Float32(Float32(-0.5) * log1p(Float32(u0 / Float32(Float32(Float32(1.0) - u0) * Float32(Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + (Float32(tan(Float32(Float32(pi) * fma(Float32(2.0), u1, Float32(0.5)))) * Float32(alphay / alphax)) ^ Float32(2.0))) * Float32(alphax * alphax))) + Float32(Float32(1.0) / Float32(alphay * alphay)))))))) end
\begin{array}{l}
\\
e^{-0.5 \cdot \mathsf{log1p}\left(\frac{u0}{\left(1 - u0\right) \cdot \left(\frac{1}{\left(1 + {\left(\tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right) \cdot \frac{alphay}{alphax}\right)}^{2}\right) \cdot \left(alphax \cdot alphax\right)} + \frac{1}{alphay \cdot alphay}\right)}\right)}
\end{array}
Initial program 99.2%
Applied rewrites99.3%
Applied rewrites100.0%
Taylor expanded in alphay around inf
Applied rewrites99.1%
Final simplification99.1%
(FPCore (u0 u1 alphax alphay)
:precision binary32
(exp
(*
-0.5
(log1p
(/
(* u0 (* alphay alphay))
(*
(- 1.0 u0)
(+
1.0
(/
1.0
(-
-1.0
(pow (* (tan (* PI (fma 2.0 u1 0.5))) (/ alphay alphax)) 2.0))))))))))
float code(float u0, float u1, float alphax, float alphay) {
return expf((-0.5f * log1pf(((u0 * (alphay * alphay)) / ((1.0f - u0) * (1.0f + (1.0f / (-1.0f - powf((tanf((((float) M_PI) * fmaf(2.0f, u1, 0.5f))) * (alphay / alphax)), 2.0f)))))))));
}
function code(u0, u1, alphax, alphay) return exp(Float32(Float32(-0.5) * log1p(Float32(Float32(u0 * Float32(alphay * alphay)) / Float32(Float32(Float32(1.0) - u0) * Float32(Float32(1.0) + Float32(Float32(1.0) / Float32(Float32(-1.0) - (Float32(tan(Float32(Float32(pi) * fma(Float32(2.0), u1, Float32(0.5)))) * Float32(alphay / alphax)) ^ Float32(2.0)))))))))) end
\begin{array}{l}
\\
e^{-0.5 \cdot \mathsf{log1p}\left(\frac{u0 \cdot \left(alphay \cdot alphay\right)}{\left(1 - u0\right) \cdot \left(1 + \frac{1}{-1 - {\left(\tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right) \cdot \frac{alphay}{alphax}\right)}^{2}}\right)}\right)}
\end{array}
Initial program 99.2%
Taylor expanded in alphay around 0
lower-/.f32N/A
unpow2N/A
associate-*l*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-*.f32N/A
Applied rewrites97.2%
Applied rewrites97.7%
Final simplification97.7%
(FPCore (u0 u1 alphax alphay)
:precision binary32
(pow
(fma
alphay
(/
(* u0 alphay)
(*
(- 1.0 u0)
(+
1.0
(/
1.0
(-
-1.0
(pow (* (tan (* PI (fma 2.0 u1 0.5))) (/ alphay alphax)) 2.0))))))
1.0)
-0.5))
float code(float u0, float u1, float alphax, float alphay) {
return powf(fmaf(alphay, ((u0 * alphay) / ((1.0f - u0) * (1.0f + (1.0f / (-1.0f - powf((tanf((((float) M_PI) * fmaf(2.0f, u1, 0.5f))) * (alphay / alphax)), 2.0f)))))), 1.0f), -0.5f);
}
function code(u0, u1, alphax, alphay) return fma(alphay, Float32(Float32(u0 * alphay) / Float32(Float32(Float32(1.0) - u0) * Float32(Float32(1.0) + Float32(Float32(1.0) / Float32(Float32(-1.0) - (Float32(tan(Float32(Float32(pi) * fma(Float32(2.0), u1, Float32(0.5)))) * Float32(alphay / alphax)) ^ Float32(2.0))))))), Float32(1.0)) ^ Float32(-0.5) end
\begin{array}{l}
\\
{\left(\mathsf{fma}\left(alphay, \frac{u0 \cdot alphay}{\left(1 - u0\right) \cdot \left(1 + \frac{1}{-1 - {\left(\tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right) \cdot \frac{alphay}{alphax}\right)}^{2}}\right)}, 1\right)\right)}^{-0.5}
\end{array}
Initial program 99.2%
Taylor expanded in alphay around 0
lower-/.f32N/A
unpow2N/A
associate-*l*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-*.f32N/A
Applied rewrites97.2%
Applied rewrites97.6%
Final simplification97.6%
(FPCore (u0 u1 alphax alphay) :precision binary32 (pow (fma alphay (/ (* u0 alphay) (- 1.0 u0)) 1.0) -0.5))
float code(float u0, float u1, float alphax, float alphay) {
return powf(fmaf(alphay, ((u0 * alphay) / (1.0f - u0)), 1.0f), -0.5f);
}
function code(u0, u1, alphax, alphay) return fma(alphay, Float32(Float32(u0 * alphay) / Float32(Float32(1.0) - u0)), Float32(1.0)) ^ Float32(-0.5) end
\begin{array}{l}
\\
{\left(\mathsf{fma}\left(alphay, \frac{u0 \cdot alphay}{1 - u0}, 1\right)\right)}^{-0.5}
\end{array}
Initial program 99.2%
Taylor expanded in alphay around 0
lower-/.f32N/A
unpow2N/A
associate-*l*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-*.f32N/A
Applied rewrites97.2%
Applied rewrites97.6%
Taylor expanded in alphay around inf
lower--.f3297.6
Applied rewrites97.6%
(FPCore (u0 u1 alphax alphay) :precision binary32 (sqrt (/ 1.0 (+ 1.0 (/ (* u0 (* alphay alphay)) (- 1.0 u0))))))
float code(float u0, float u1, float alphax, float alphay) {
return sqrtf((1.0f / (1.0f + ((u0 * (alphay * alphay)) / (1.0f - u0)))));
}
real(4) function code(u0, u1, alphax, alphay)
real(4), intent (in) :: u0
real(4), intent (in) :: u1
real(4), intent (in) :: alphax
real(4), intent (in) :: alphay
code = sqrt((1.0e0 / (1.0e0 + ((u0 * (alphay * alphay)) / (1.0e0 - u0)))))
end function
function code(u0, u1, alphax, alphay) return sqrt(Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(Float32(u0 * Float32(alphay * alphay)) / Float32(Float32(1.0) - u0))))) end
function tmp = code(u0, u1, alphax, alphay) tmp = sqrt((single(1.0) / (single(1.0) + ((u0 * (alphay * alphay)) / (single(1.0) - u0))))); end
\begin{array}{l}
\\
\sqrt{\frac{1}{1 + \frac{u0 \cdot \left(alphay \cdot alphay\right)}{1 - u0}}}
\end{array}
Initial program 99.2%
Taylor expanded in alphay around 0
lower-/.f32N/A
unpow2N/A
associate-*l*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-*.f32N/A
Applied rewrites97.2%
Applied rewrites97.2%
Taylor expanded in alphax around 0
lower-sqrt.f32N/A
lower-/.f32N/A
lower-+.f32N/A
lower-/.f32N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower--.f3297.5
Applied rewrites97.5%
Final simplification97.5%
(FPCore (u0 u1 alphax alphay) :precision binary32 (/ 1.0 (sqrt (fma (/ (* u0 alphay) (- 1.0 u0)) alphay 1.0))))
float code(float u0, float u1, float alphax, float alphay) {
return 1.0f / sqrtf(fmaf(((u0 * alphay) / (1.0f - u0)), alphay, 1.0f));
}
function code(u0, u1, alphax, alphay) return Float32(Float32(1.0) / sqrt(fma(Float32(Float32(u0 * alphay) / Float32(Float32(1.0) - u0)), alphay, Float32(1.0)))) end
\begin{array}{l}
\\
\frac{1}{\sqrt{\mathsf{fma}\left(\frac{u0 \cdot alphay}{1 - u0}, alphay, 1\right)}}
\end{array}
Initial program 99.2%
Taylor expanded in alphay around 0
lower-/.f32N/A
unpow2N/A
associate-*l*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-*.f32N/A
Applied rewrites97.2%
Applied rewrites97.2%
Taylor expanded in alphay around inf
lower--.f3297.2
Applied rewrites97.2%
(FPCore (u0 u1 alphax alphay) :precision binary32 1.0)
float code(float u0, float u1, float alphax, float alphay) {
return 1.0f;
}
real(4) function code(u0, u1, alphax, alphay)
real(4), intent (in) :: u0
real(4), intent (in) :: u1
real(4), intent (in) :: alphax
real(4), intent (in) :: alphay
code = 1.0e0
end function
function code(u0, u1, alphax, alphay) return Float32(1.0) end
function tmp = code(u0, u1, alphax, alphay) tmp = single(1.0); end
\begin{array}{l}
\\
1
\end{array}
Initial program 99.2%
Taylor expanded in alphay around 0
lower-/.f32N/A
unpow2N/A
associate-*l*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-*.f32N/A
Applied rewrites97.2%
Taylor expanded in alphay around 0
Applied rewrites90.7%
herbie shell --seed 2024219
(FPCore (u0 u1 alphax alphay)
:name "Trowbridge-Reitz Sample, sample surface normal, cosTheta"
:precision binary32
:pre (and (and (and (and (<= 2.328306437e-10 u0) (<= u0 1.0)) (and (<= 2.328306437e-10 u1) (<= u1 0.5))) (and (<= 0.0001 alphax) (<= alphax 1.0))) (and (<= 0.0001 alphay) (<= alphay 1.0)))
(/ 1.0 (sqrt (+ 1.0 (/ (* (/ 1.0 (+ (/ (* (cos (atan (* (/ alphay alphax) (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI)))))) (cos (atan (* (/ alphay alphax) (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI))))))) (* alphax alphax)) (/ (* (sin (atan (* (/ alphay alphax) (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI)))))) (sin (atan (* (/ alphay alphax) (tan (+ (* (* 2.0 PI) u1) (* 0.5 PI))))))) (* alphay alphay)))) u0) (- 1.0 u0))))))