Trowbridge-Reitz Sample, sample surface normal, cosTheta

Percentage Accurate: 99.4% → 99.4%

Time: 1.5min

Alternatives: 4

Speedup: 1.8×

Specification

\[\left(\left(\left(2.328306437 \cdot 10^{-10} \leq u0 \land u0 \leq 1\right) \land \left(2.328306437 \cdot 10^{-10} \leq u1 \land u1 \leq 0.5\right)\right) \land \left(0.0001 \leq alphax \land alphax \leq 1\right)\right) \land \left(0.0001 \leq alphay \land alphay \leq 1\right)\]

Math

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)\\ t_1 := \sin t_0\\ t_2 := \cos t_0\\ \frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{t_2 \cdot t_2}{alphax \cdot alphax} + \frac{t_1 \cdot t_1}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \end{array} \end{array} \]

FPCore

(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)))))))

C

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))));
}

Julia

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

MATLAB

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

Initial Program: 99.4% accurate, 1.0× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)\\ t_1 := \sin t_0\\ t_2 := \cos t_0\\ \frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{t_2 \cdot t_2}{alphax \cdot alphax} + \frac{t_1 \cdot t_1}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \end{array} \end{array} \]

FPCore

(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)))))))

C

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))));
}

Julia

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

MATLAB

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

Alternative 1: 99.4% accurate, 1.8× speedup

Math

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\\ \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} t_0}{alphay}, \frac{\frac{1}{\mathsf{hypot}\left(1, t_0\right)}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \end{array} \end{array} \]

FPCore

(FPCore (u0 u1 alphax alphay)
 :precision binary32
 (let* ((t_0 (* (/ alphay alphax) (tan (* (fma 2.0 u1 0.5) PI)))))
   (/
    1.0
    (sqrt
     (+
      1.0
      (/
       u0
       (*
        (pow
         (hypot (/ (sin (atan t_0)) alphay) (/ (/ 1.0 (hypot 1.0 t_0)) alphax))
         2.0)
        (- 1.0 u0))))))))

C

float code(float u0, float u1, float alphax, float alphay) {
	float t_0 = (alphay / alphax) * tanf((fmaf(2.0f, u1, 0.5f) * ((float) M_PI)));
	return 1.0f / sqrtf((1.0f + (u0 / (powf(hypotf((sinf(atanf(t_0)) / alphay), ((1.0f / hypotf(1.0f, t_0)) / alphax)), 2.0f) * (1.0f - u0)))));
}

Julia

function code(u0, u1, alphax, alphay)
	t_0 = Float32(Float32(alphay / alphax) * tan(Float32(fma(Float32(2.0), u1, Float32(0.5)) * Float32(pi))))
	return Float32(Float32(1.0) / sqrt(Float32(Float32(1.0) + Float32(u0 / Float32((hypot(Float32(sin(atan(t_0)) / alphay), Float32(Float32(Float32(1.0) / hypot(Float32(1.0), t_0)) / alphax)) ^ Float32(2.0)) * Float32(Float32(1.0) - u0))))))
end

Derivation

1. Initial program 99.3%

   \[\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphax \cdot alphax} + \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \]

3. Simplified 99.3%

   \[\leadsto \color{blue}{\frac{1}{\sqrt{1 + \frac{u0}{\mathsf{fma}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right) \cdot \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphax \cdot alphax}\right) \cdot \left(1 - u0\right)}}}} \]
4. Step-by-step derivation

   1. expm1-log1p-u 99.3%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\mathsf{fma}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right) \cdot \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphax \cdot alphax}\right)\right)\right)} \cdot \left(1 - u0\right)}}} \]

   2. expm1-udef 99.3%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{\left(e^{\mathsf{log1p}\left(\mathsf{fma}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right) \cdot \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphax \cdot alphax}\right)\right)} - 1\right)} \cdot \left(1 - u0\right)}}} \]

5. Applied egg-rr 99.3%

   \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{\left(e^{\mathsf{log1p}\left({\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)}{alphay}, \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)}{alphax}\right)\right)}^{2}\right)} - 1\right)} \cdot \left(1 - u0\right)}}} \]
6. Step-by-step derivation

   1. expm1-def 99.3%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left({\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)}{alphay}, \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)}{alphax}\right)\right)}^{2}\right)\right)} \cdot \left(1 - u0\right)}}} \]

   2. expm1-log1p 99.3%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)}{alphay}, \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)}{alphax}\right)\right)}^{2}} \cdot \left(1 - u0\right)}}} \]

7. Simplified 99.3%

   \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphax}\right)\right)}^{2}} \cdot \left(1 - u0\right)}}} \]
8. Step-by-step derivation

   1. cos-atan 99.4%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{\color{blue}{\frac{1}{\sqrt{1 + \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right) \cdot \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}}}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

   2. hypot-1-def 99.4%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{\frac{1}{\color{blue}{\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

   3. add-sqr-sqrt 99.4%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{\color{blue}{\sqrt{\frac{1}{\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}} \cdot \sqrt{\frac{1}{\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}}}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

   4. inv-pow 99.4%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{\sqrt{\color{blue}{{\left(\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)\right)}^{-1}}} \cdot \sqrt{\frac{1}{\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

   5. sqrt-pow1 99.4%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{\color{blue}{{\left(\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)\right)}^{\left(\frac{-1}{2}\right)}} \cdot \sqrt{\frac{1}{\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

   6. fma-def 99.4%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{{\left(\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\color{blue}{\left(2 \cdot u1 + 0.5\right)} \cdot \pi\right)\right)\right)}^{\left(\frac{-1}{2}\right)} \cdot \sqrt{\frac{1}{\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

   7. *-commutative 99.4%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{{\left(\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \color{blue}{\left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)}\right)\right)}^{\left(\frac{-1}{2}\right)} \cdot \sqrt{\frac{1}{\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

   8. fma-def 99.4%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{{\left(\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \color{blue}{\mathsf{fma}\left(2, u1, 0.5\right)}\right)\right)\right)}^{\left(\frac{-1}{2}\right)} \cdot \sqrt{\frac{1}{\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

   9. metadata-eval 99.4%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{{\left(\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)\right)}^{\color{blue}{-0.5}} \cdot \sqrt{\frac{1}{\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

9. Applied egg-rr 99.4%

   \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{\color{blue}{{\left(\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)\right)}^{-0.5} \cdot {\left(\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)\right)}^{-0.5}}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]
10. Step-by-step derivation

    1. pow-sqr 99.4%

       \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{\color{blue}{{\left(\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)\right)}^{\left(2 \cdot -0.5\right)}}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

    2. metadata-eval 99.4%

       \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{{\left(\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)\right)}^{\color{blue}{-1}}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

    3. unpow-1 99.4%

       \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{\color{blue}{\frac{1}{\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)}}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

    4. *-commutative 99.4%

       \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{\frac{1}{\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \color{blue}{\left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)}\right)}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

11. Simplified 99.4%

    \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{\color{blue}{\frac{1}{\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

12. Final simplification 99.4%

    \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{\frac{1}{\mathsf{hypot}\left(1, \frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

Alternative 2: 98.2% accurate, 1.8× speedup

Math

\[\begin{array}{l} \\ \frac{1}{\sqrt{1 + \frac{u0}{\left(1 - u0\right) \cdot {\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(0.5 \cdot \pi\right)\right)}{alphay}, \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphax}\right)\right)}^{2}}}} \end{array} \]

FPCore

(FPCore (u0 u1 alphax alphay)
 :precision binary32
 (/
  1.0
  (sqrt
   (+
    1.0
    (/
     u0
     (*
      (- 1.0 u0)
      (pow
       (hypot
        (/ (sin (atan (* (/ alphay alphax) (tan (* 0.5 PI))))) alphay)
        (/
         (cos (atan (* (/ alphay alphax) (tan (* (fma 2.0 u1 0.5) PI)))))
         alphax))
       2.0)))))))

C

float code(float u0, float u1, float alphax, float alphay) {
	return 1.0f / sqrtf((1.0f + (u0 / ((1.0f - u0) * powf(hypotf((sinf(atanf(((alphay / alphax) * tanf((0.5f * ((float) M_PI)))))) / alphay), (cosf(atanf(((alphay / alphax) * tanf((fmaf(2.0f, u1, 0.5f) * ((float) M_PI)))))) / alphax)), 2.0f)))));
}

Julia

function code(u0, u1, alphax, alphay)
	return Float32(Float32(1.0) / sqrt(Float32(Float32(1.0) + Float32(u0 / Float32(Float32(Float32(1.0) - u0) * (hypot(Float32(sin(atan(Float32(Float32(alphay / alphax) * tan(Float32(Float32(0.5) * Float32(pi)))))) / alphay), Float32(cos(atan(Float32(Float32(alphay / alphax) * tan(Float32(fma(Float32(2.0), u1, Float32(0.5)) * Float32(pi)))))) / alphax)) ^ Float32(2.0)))))))
end

Derivation

1. Initial program 99.3%

   \[\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphax \cdot alphax} + \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \]

3. Simplified 99.3%

   \[\leadsto \color{blue}{\frac{1}{\sqrt{1 + \frac{u0}{\mathsf{fma}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right) \cdot \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphax \cdot alphax}\right) \cdot \left(1 - u0\right)}}}} \]
4. Step-by-step derivation

   1. expm1-log1p-u 99.3%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\mathsf{fma}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right) \cdot \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphax \cdot alphax}\right)\right)\right)} \cdot \left(1 - u0\right)}}} \]

   2. expm1-udef 99.3%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{\left(e^{\mathsf{log1p}\left(\mathsf{fma}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right) \cdot \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphax \cdot alphax}\right)\right)} - 1\right)} \cdot \left(1 - u0\right)}}} \]

5. Applied egg-rr 99.3%

   \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{\left(e^{\mathsf{log1p}\left({\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)}{alphay}, \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)}{alphax}\right)\right)}^{2}\right)} - 1\right)} \cdot \left(1 - u0\right)}}} \]
6. Step-by-step derivation

   1. expm1-def 99.3%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left({\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)}{alphay}, \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)}{alphax}\right)\right)}^{2}\right)\right)} \cdot \left(1 - u0\right)}}} \]

   2. expm1-log1p 99.3%

      \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)}{alphay}, \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \mathsf{fma}\left(2, u1, 0.5\right)\right)\right)}{alphax}\right)\right)}^{2}} \cdot \left(1 - u0\right)}}} \]

7. Simplified 99.3%

   \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}, \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphax}\right)\right)}^{2}} \cdot \left(1 - u0\right)}}} \]

8. Taylor expanded in u1 around 0 98.8%

   \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \color{blue}{\left(0.5 \cdot \pi\right)}\right)}{alphay}, \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphax}\right)\right)}^{2} \cdot \left(1 - u0\right)}}} \]

9. Final simplification 98.8%

   \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\left(1 - u0\right) \cdot {\left(\mathsf{hypot}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(0.5 \cdot \pi\right)\right)}{alphay}, \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphax}\right)\right)}^{2}}}} \]

Alternative 3: 97.7% accurate, 3.0× speedup

Math

\[\begin{array}{l} \\ \frac{1}{\sqrt{1 + \frac{u0}{\left(1 - u0\right) \cdot {\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}\right)}^{2}}}} \end{array} \]

FPCore

(FPCore (u0 u1 alphax alphay)
 :precision binary32
 (/
  1.0
  (sqrt
   (+
    1.0
    (/
     u0
     (*
      (- 1.0 u0)
      (pow
       (/
        (sin (atan (* (/ alphay alphax) (tan (* (fma 2.0 u1 0.5) PI)))))
        alphay)
       2.0)))))))

C

float code(float u0, float u1, float alphax, float alphay) {
	return 1.0f / sqrtf((1.0f + (u0 / ((1.0f - u0) * powf((sinf(atanf(((alphay / alphax) * tanf((fmaf(2.0f, u1, 0.5f) * ((float) M_PI)))))) / alphay), 2.0f)))));
}

Julia

function code(u0, u1, alphax, alphay)
	return Float32(Float32(1.0) / sqrt(Float32(Float32(1.0) + Float32(u0 / Float32(Float32(Float32(1.0) - u0) * (Float32(sin(atan(Float32(Float32(alphay / alphax) * tan(Float32(fma(Float32(2.0), u1, Float32(0.5)) * Float32(pi)))))) / alphay) ^ Float32(2.0)))))))
end

Derivation

1. Initial program 99.3%

   \[\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphax \cdot alphax} + \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \]

3. Simplified 99.3%

   \[\leadsto \color{blue}{\frac{1}{\sqrt{1 + \frac{u0}{\mathsf{fma}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right) \cdot \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphax \cdot alphax}\right) \cdot \left(1 - u0\right)}}}} \]

4. Taylor expanded in alphay around 0 98.1%

   \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{\frac{{\sin \tan^{-1} \left(\frac{\tan \left(\left(2 \cdot u1 + 0.5\right) \cdot \pi\right) \cdot alphay}{alphax}\right)}^{2}}{{alphay}^{2}}} \cdot \left(1 - u0\right)}}} \]

6. Simplified 98.1%

   \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{{\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}\right)}^{2}} \cdot \left(1 - u0\right)}}} \]

7. Final simplification 98.1%

   \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\left(1 - u0\right) \cdot {\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}\right)}^{2}}}} \]

Alternative 4: 97.6% accurate, 3.5× speedup

Math

\[\begin{array}{l} \\ \frac{1}{\sqrt{1 + \frac{u0}{\left(1 - u0\right) \cdot {\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(0.5 \cdot \pi\right)\right)}{alphay}\right)}^{2}}}} \end{array} \]

FPCore

(FPCore (u0 u1 alphax alphay)
 :precision binary32
 (/
  1.0
  (sqrt
   (+
    1.0
    (/
     u0
     (*
      (- 1.0 u0)
      (pow
       (/ (sin (atan (* (/ alphay alphax) (tan (* 0.5 PI))))) alphay)
       2.0)))))))

C

float code(float u0, float u1, float alphax, float alphay) {
	return 1.0f / sqrtf((1.0f + (u0 / ((1.0f - u0) * powf((sinf(atanf(((alphay / alphax) * tanf((0.5f * ((float) M_PI)))))) / alphay), 2.0f)))));
}

Julia

function code(u0, u1, alphax, alphay)
	return Float32(Float32(1.0) / sqrt(Float32(Float32(1.0) + Float32(u0 / Float32(Float32(Float32(1.0) - u0) * (Float32(sin(atan(Float32(Float32(alphay / alphax) * tan(Float32(Float32(0.5) * Float32(pi)))))) / alphay) ^ Float32(2.0)))))))
end

MATLAB

function tmp = code(u0, u1, alphax, alphay)
	tmp = single(1.0) / sqrt((single(1.0) + (u0 / ((single(1.0) - u0) * ((sin(atan(((alphay / alphax) * tan((single(0.5) * single(pi)))))) / alphay) ^ single(2.0))))));
end

Derivation

1. Initial program 99.3%

   \[\frac{1}{\sqrt{1 + \frac{\frac{1}{\frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphax \cdot alphax} + \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right) \cdot \sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\left(2 \cdot \pi\right) \cdot u1 + 0.5 \cdot \pi\right)\right)}{alphay \cdot alphay}} \cdot u0}{1 - u0}}} \]

3. Simplified 99.3%

   \[\leadsto \color{blue}{\frac{1}{\sqrt{1 + \frac{u0}{\mathsf{fma}\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphay}, \cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right) \cdot \frac{\cos \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\pi \cdot \left(2 \cdot u1 + 0.5\right)\right)\right)}{alphax \cdot alphax}\right) \cdot \left(1 - u0\right)}}}} \]

4. Taylor expanded in alphay around 0 98.1%

   \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{\frac{{\sin \tan^{-1} \left(\frac{\tan \left(\left(2 \cdot u1 + 0.5\right) \cdot \pi\right) \cdot alphay}{alphax}\right)}^{2}}{{alphay}^{2}}} \cdot \left(1 - u0\right)}}} \]

6. Simplified 98.1%

   \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\color{blue}{{\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(\mathsf{fma}\left(2, u1, 0.5\right) \cdot \pi\right)\right)}{alphay}\right)}^{2}} \cdot \left(1 - u0\right)}}} \]

7. Taylor expanded in u1 around 0 97.9%

   \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{{\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \color{blue}{\left(0.5 \cdot \pi\right)}\right)}{alphay}\right)}^{2} \cdot \left(1 - u0\right)}}} \]

8. Final simplification 97.9%

   \[\leadsto \frac{1}{\sqrt{1 + \frac{u0}{\left(1 - u0\right) \cdot {\left(\frac{\sin \tan^{-1} \left(\frac{alphay}{alphax} \cdot \tan \left(0.5 \cdot \pi\right)\right)}{alphay}\right)}^{2}}}} \]

Reproduce

herbie shell --seed 2023268 
(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))))))