Beckmann Sample, normalization factor

Percentage Accurate: 97.8% → 98.5%
Time: 19.3s
Alternatives: 9
Speedup: 0.6×

Specification

?
\[\left(0 < cosTheta \land cosTheta < 0.9999\right) \land \left(-1 < c \land c < 1\right)\]
\[\begin{array}{l} \\ \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/
  1.0
  (+
   (+ 1.0 c)
   (*
    (* (/ 1.0 (sqrt PI)) (/ (sqrt (- (- 1.0 cosTheta) cosTheta)) cosTheta))
    (exp (* (- cosTheta) cosTheta))))))
float code(float cosTheta, float c) {
	return 1.0f / ((1.0f + c) + (((1.0f / sqrtf(((float) M_PI))) * (sqrtf(((1.0f - cosTheta) - cosTheta)) / cosTheta)) * expf((-cosTheta * cosTheta))));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(Float32(1.0) / sqrt(Float32(pi))) * Float32(sqrt(Float32(Float32(Float32(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp(Float32(Float32(-cosTheta) * cosTheta)))))
end
function tmp = code(cosTheta, c)
	tmp = single(1.0) / ((single(1.0) + c) + (((single(1.0) / sqrt(single(pi))) * (sqrt(((single(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp((-cosTheta * cosTheta))));
end
\begin{array}{l}

\\
\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}}
\end{array}

Sampling outcomes in binary32 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 9 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: 97.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/
  1.0
  (+
   (+ 1.0 c)
   (*
    (* (/ 1.0 (sqrt PI)) (/ (sqrt (- (- 1.0 cosTheta) cosTheta)) cosTheta))
    (exp (* (- cosTheta) cosTheta))))))
float code(float cosTheta, float c) {
	return 1.0f / ((1.0f + c) + (((1.0f / sqrtf(((float) M_PI))) * (sqrtf(((1.0f - cosTheta) - cosTheta)) / cosTheta)) * expf((-cosTheta * cosTheta))));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(Float32(Float32(1.0) + c) + Float32(Float32(Float32(Float32(1.0) / sqrt(Float32(pi))) * Float32(sqrt(Float32(Float32(Float32(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp(Float32(Float32(-cosTheta) * cosTheta)))))
end
function tmp = code(cosTheta, c)
	tmp = single(1.0) / ((single(1.0) + c) + (((single(1.0) / sqrt(single(pi))) * (sqrt(((single(1.0) - cosTheta) - cosTheta)) / cosTheta)) * exp((-cosTheta * cosTheta))));
end
\begin{array}{l}

\\
\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}}
\end{array}

Alternative 1: 98.5% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \frac{1}{1 + \mathsf{fma}\left(\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta \cdot \sqrt{\pi}}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/
  1.0
  (+
   1.0
   (fma
    (/ (sqrt (+ 1.0 (* cosTheta -2.0))) (* cosTheta (sqrt PI)))
    (pow (exp (- cosTheta)) cosTheta)
    c))))
float code(float cosTheta, float c) {
	return 1.0f / (1.0f + fmaf((sqrtf((1.0f + (cosTheta * -2.0f))) / (cosTheta * sqrtf(((float) M_PI)))), powf(expf(-cosTheta), cosTheta), c));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(Float32(1.0) + fma(Float32(sqrt(Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0)))) / Float32(cosTheta * sqrt(Float32(pi)))), (exp(Float32(-cosTheta)) ^ cosTheta), c)))
end
\begin{array}{l}

\\
\frac{1}{1 + \mathsf{fma}\left(\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta \cdot \sqrt{\pi}}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)}
\end{array}
Derivation
  1. Initial program 97.5%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. associate-+l+97.5%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(c + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}} \]
    2. +-commutative97.5%

      \[\leadsto \frac{1}{1 + \color{blue}{\left(\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta} + c\right)}} \]
    3. fma-define97.5%

      \[\leadsto \frac{1}{1 + \color{blue}{\mathsf{fma}\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}, e^{\left(-cosTheta\right) \cdot cosTheta}, c\right)}} \]
  3. Simplified98.4%

    \[\leadsto \color{blue}{\frac{1}{1 + \mathsf{fma}\left(\frac{\sqrt{1 + cosTheta \cdot -2}}{\sqrt{\pi} \cdot cosTheta}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)}} \]
  4. Add Preprocessing
  5. Final simplification98.4%

    \[\leadsto \frac{1}{1 + \mathsf{fma}\left(\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta \cdot \sqrt{\pi}}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)} \]
  6. Add Preprocessing

Alternative 2: 98.0% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \frac{1}{1 + \mathsf{fma}\left(\frac{\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/
  1.0
  (+
   1.0
   (fma
    (/ (sqrt (/ (fma cosTheta -2.0 1.0) PI)) cosTheta)
    (pow (exp (- cosTheta)) cosTheta)
    c))))
float code(float cosTheta, float c) {
	return 1.0f / (1.0f + fmaf((sqrtf((fmaf(cosTheta, -2.0f, 1.0f) / ((float) M_PI))) / cosTheta), powf(expf(-cosTheta), cosTheta), c));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(Float32(1.0) + fma(Float32(sqrt(Float32(fma(cosTheta, Float32(-2.0), Float32(1.0)) / Float32(pi))) / cosTheta), (exp(Float32(-cosTheta)) ^ cosTheta), c)))
end
\begin{array}{l}

\\
\frac{1}{1 + \mathsf{fma}\left(\frac{\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)}
\end{array}
Derivation
  1. Initial program 97.5%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. associate-+l+97.5%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(c + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}} \]
    2. +-commutative97.5%

      \[\leadsto \frac{1}{1 + \color{blue}{\left(\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta} + c\right)}} \]
    3. fma-define97.5%

      \[\leadsto \frac{1}{1 + \color{blue}{\mathsf{fma}\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}, e^{\left(-cosTheta\right) \cdot cosTheta}, c\right)}} \]
  3. Simplified98.4%

    \[\leadsto \color{blue}{\frac{1}{1 + \mathsf{fma}\left(\frac{\sqrt{1 + cosTheta \cdot -2}}{\sqrt{\pi} \cdot cosTheta}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. *-un-lft-identity98.4%

      \[\leadsto \frac{1}{1 + \mathsf{fma}\left(\color{blue}{1 \cdot \frac{\sqrt{1 + cosTheta \cdot -2}}{\sqrt{\pi} \cdot cosTheta}}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)} \]
    2. associate-/r*97.8%

      \[\leadsto \frac{1}{1 + \mathsf{fma}\left(1 \cdot \color{blue}{\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{\sqrt{\pi}}}{cosTheta}}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)} \]
    3. sqrt-undiv97.9%

      \[\leadsto \frac{1}{1 + \mathsf{fma}\left(1 \cdot \frac{\color{blue}{\sqrt{\frac{1 + cosTheta \cdot -2}{\pi}}}}{cosTheta}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)} \]
    4. +-commutative97.9%

      \[\leadsto \frac{1}{1 + \mathsf{fma}\left(1 \cdot \frac{\sqrt{\frac{\color{blue}{cosTheta \cdot -2 + 1}}{\pi}}}{cosTheta}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)} \]
    5. fma-define97.9%

      \[\leadsto \frac{1}{1 + \mathsf{fma}\left(1 \cdot \frac{\sqrt{\frac{\color{blue}{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{\pi}}}{cosTheta}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)} \]
  6. Applied egg-rr97.9%

    \[\leadsto \frac{1}{1 + \mathsf{fma}\left(\color{blue}{1 \cdot \frac{\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta}}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)} \]
  7. Step-by-step derivation
    1. *-lft-identity97.9%

      \[\leadsto \frac{1}{1 + \mathsf{fma}\left(\color{blue}{\frac{\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta}}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)} \]
  8. Simplified97.9%

    \[\leadsto \frac{1}{1 + \mathsf{fma}\left(\color{blue}{\frac{\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta}}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)} \]
  9. Final simplification97.9%

    \[\leadsto \frac{1}{1 + \mathsf{fma}\left(\frac{\sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)} \]
  10. Add Preprocessing

Alternative 3: 97.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{cosTheta \cdot \left(\frac{1}{cosTheta \cdot \pi} - \frac{2}{\pi}\right)}}{cosTheta}} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/
  1.0
  (+
   1.0
   (/
    (*
     (exp (- (pow cosTheta 2.0)))
     (sqrt (* cosTheta (- (/ 1.0 (* cosTheta PI)) (/ 2.0 PI)))))
    cosTheta))))
float code(float cosTheta, float c) {
	return 1.0f / (1.0f + ((expf(-powf(cosTheta, 2.0f)) * sqrtf((cosTheta * ((1.0f / (cosTheta * ((float) M_PI))) - (2.0f / ((float) M_PI)))))) / cosTheta));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(Float32(exp(Float32(-(cosTheta ^ Float32(2.0)))) * sqrt(Float32(cosTheta * Float32(Float32(Float32(1.0) / Float32(cosTheta * Float32(pi))) - Float32(Float32(2.0) / Float32(pi)))))) / cosTheta)))
end
function tmp = code(cosTheta, c)
	tmp = single(1.0) / (single(1.0) + ((exp(-(cosTheta ^ single(2.0))) * sqrt((cosTheta * ((single(1.0) / (cosTheta * single(pi))) - (single(2.0) / single(pi)))))) / cosTheta));
end
\begin{array}{l}

\\
\frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{cosTheta \cdot \left(\frac{1}{cosTheta \cdot \pi} - \frac{2}{\pi}\right)}}{cosTheta}}
\end{array}
Derivation
  1. Initial program 97.5%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. +-commutative97.5%

      \[\leadsto \frac{1}{\color{blue}{\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta} + \left(1 + c\right)}} \]
    2. fma-define97.5%

      \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)}} \]
    3. associate-*l/98.2%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\color{blue}{\frac{1 \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}}{\sqrt{\pi}}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    4. *-lft-identity98.2%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    5. associate--l-98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{\color{blue}{1 - \left(cosTheta + cosTheta\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    6. sub-neg98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{\color{blue}{1 + \left(-\left(cosTheta + cosTheta\right)\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    7. neg-mul-198.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + \color{blue}{-1 \cdot \left(cosTheta + cosTheta\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    8. distribute-lft-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + \color{blue}{\left(-1 \cdot cosTheta + -1 \cdot cosTheta\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    9. distribute-rgt-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + \color{blue}{cosTheta \cdot \left(-1 + -1\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    10. metadata-eval98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot \color{blue}{-2}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    11. distribute-lft-neg-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, e^{\color{blue}{-cosTheta \cdot cosTheta}}, 1 + c\right)} \]
    12. distribute-rgt-neg-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, e^{\color{blue}{cosTheta \cdot \left(-cosTheta\right)}}, 1 + c\right)} \]
    13. exp-prod98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, \color{blue}{{\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}}, 1 + c\right)} \]
  3. Simplified98.1%

    \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. clear-num98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{1}{\frac{cosTheta}{\sqrt{1 + cosTheta \cdot -2}}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
    2. inv-pow98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{{\left(\frac{cosTheta}{\sqrt{1 + cosTheta \cdot -2}}\right)}^{-1}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
    3. +-commutative98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{{\left(\frac{cosTheta}{\sqrt{\color{blue}{cosTheta \cdot -2 + 1}}}\right)}^{-1}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
    4. fma-define98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{{\left(\frac{cosTheta}{\sqrt{\color{blue}{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}\right)}^{-1}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  6. Applied egg-rr98.1%

    \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{{\left(\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}\right)}^{-1}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  7. Step-by-step derivation
    1. unpow-198.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{1}{\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  8. Simplified98.1%

    \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{1}{\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  9. Taylor expanded in c around 0 97.4%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{e^{-1 \cdot {cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 + -2 \cdot cosTheta}{\pi}}}} \]
  10. Step-by-step derivation
    1. associate-*l/97.7%

      \[\leadsto \frac{1}{1 + \color{blue}{\frac{e^{-1 \cdot {cosTheta}^{2}} \cdot \sqrt{\frac{1 + -2 \cdot cosTheta}{\pi}}}{cosTheta}}} \]
    2. neg-mul-197.7%

      \[\leadsto \frac{1}{1 + \frac{e^{\color{blue}{-{cosTheta}^{2}}} \cdot \sqrt{\frac{1 + -2 \cdot cosTheta}{\pi}}}{cosTheta}} \]
    3. +-commutative97.7%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\color{blue}{-2 \cdot cosTheta + 1}}{\pi}}}{cosTheta}} \]
    4. *-commutative97.7%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\color{blue}{cosTheta \cdot -2} + 1}{\pi}}}{cosTheta}} \]
    5. fma-undefine97.7%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\color{blue}{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{\pi}}}{cosTheta}} \]
  11. Simplified97.7%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta}}} \]
  12. Taylor expanded in cosTheta around inf 97.7%

    \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\color{blue}{cosTheta \cdot \left(\frac{1}{cosTheta \cdot \pi} - 2 \cdot \frac{1}{\pi}\right)}}}{cosTheta}} \]
  13. Step-by-step derivation
    1. associate-*r/97.7%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{cosTheta \cdot \left(\frac{1}{cosTheta \cdot \pi} - \color{blue}{\frac{2 \cdot 1}{\pi}}\right)}}{cosTheta}} \]
    2. metadata-eval97.7%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{cosTheta \cdot \left(\frac{1}{cosTheta \cdot \pi} - \frac{\color{blue}{2}}{\pi}\right)}}{cosTheta}} \]
  14. Simplified97.7%

    \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\color{blue}{cosTheta \cdot \left(\frac{1}{cosTheta \cdot \pi} - \frac{2}{\pi}\right)}}}{cosTheta}} \]
  15. Final simplification97.7%

    \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{cosTheta \cdot \left(\frac{1}{cosTheta \cdot \pi} - \frac{2}{\pi}\right)}}{cosTheta}} \]
  16. Add Preprocessing

Alternative 4: 97.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{-2 \cdot \frac{cosTheta}{\pi} + \frac{1}{\pi}}}{cosTheta}} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/
  1.0
  (+
   1.0
   (/
    (*
     (exp (- (pow cosTheta 2.0)))
     (sqrt (+ (* -2.0 (/ cosTheta PI)) (/ 1.0 PI))))
    cosTheta))))
float code(float cosTheta, float c) {
	return 1.0f / (1.0f + ((expf(-powf(cosTheta, 2.0f)) * sqrtf(((-2.0f * (cosTheta / ((float) M_PI))) + (1.0f / ((float) M_PI))))) / cosTheta));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(Float32(exp(Float32(-(cosTheta ^ Float32(2.0)))) * sqrt(Float32(Float32(Float32(-2.0) * Float32(cosTheta / Float32(pi))) + Float32(Float32(1.0) / Float32(pi))))) / cosTheta)))
end
function tmp = code(cosTheta, c)
	tmp = single(1.0) / (single(1.0) + ((exp(-(cosTheta ^ single(2.0))) * sqrt(((single(-2.0) * (cosTheta / single(pi))) + (single(1.0) / single(pi))))) / cosTheta));
end
\begin{array}{l}

\\
\frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{-2 \cdot \frac{cosTheta}{\pi} + \frac{1}{\pi}}}{cosTheta}}
\end{array}
Derivation
  1. Initial program 97.5%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. +-commutative97.5%

      \[\leadsto \frac{1}{\color{blue}{\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta} + \left(1 + c\right)}} \]
    2. fma-define97.5%

      \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)}} \]
    3. associate-*l/98.2%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\color{blue}{\frac{1 \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}}{\sqrt{\pi}}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    4. *-lft-identity98.2%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    5. associate--l-98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{\color{blue}{1 - \left(cosTheta + cosTheta\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    6. sub-neg98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{\color{blue}{1 + \left(-\left(cosTheta + cosTheta\right)\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    7. neg-mul-198.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + \color{blue}{-1 \cdot \left(cosTheta + cosTheta\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    8. distribute-lft-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + \color{blue}{\left(-1 \cdot cosTheta + -1 \cdot cosTheta\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    9. distribute-rgt-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + \color{blue}{cosTheta \cdot \left(-1 + -1\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    10. metadata-eval98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot \color{blue}{-2}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    11. distribute-lft-neg-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, e^{\color{blue}{-cosTheta \cdot cosTheta}}, 1 + c\right)} \]
    12. distribute-rgt-neg-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, e^{\color{blue}{cosTheta \cdot \left(-cosTheta\right)}}, 1 + c\right)} \]
    13. exp-prod98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, \color{blue}{{\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}}, 1 + c\right)} \]
  3. Simplified98.1%

    \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. clear-num98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{1}{\frac{cosTheta}{\sqrt{1 + cosTheta \cdot -2}}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
    2. inv-pow98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{{\left(\frac{cosTheta}{\sqrt{1 + cosTheta \cdot -2}}\right)}^{-1}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
    3. +-commutative98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{{\left(\frac{cosTheta}{\sqrt{\color{blue}{cosTheta \cdot -2 + 1}}}\right)}^{-1}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
    4. fma-define98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{{\left(\frac{cosTheta}{\sqrt{\color{blue}{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}\right)}^{-1}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  6. Applied egg-rr98.1%

    \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{{\left(\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}\right)}^{-1}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  7. Step-by-step derivation
    1. unpow-198.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{1}{\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  8. Simplified98.1%

    \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{1}{\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  9. Taylor expanded in c around 0 97.4%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{e^{-1 \cdot {cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 + -2 \cdot cosTheta}{\pi}}}} \]
  10. Step-by-step derivation
    1. associate-*l/97.7%

      \[\leadsto \frac{1}{1 + \color{blue}{\frac{e^{-1 \cdot {cosTheta}^{2}} \cdot \sqrt{\frac{1 + -2 \cdot cosTheta}{\pi}}}{cosTheta}}} \]
    2. neg-mul-197.7%

      \[\leadsto \frac{1}{1 + \frac{e^{\color{blue}{-{cosTheta}^{2}}} \cdot \sqrt{\frac{1 + -2 \cdot cosTheta}{\pi}}}{cosTheta}} \]
    3. +-commutative97.7%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\color{blue}{-2 \cdot cosTheta + 1}}{\pi}}}{cosTheta}} \]
    4. *-commutative97.7%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\color{blue}{cosTheta \cdot -2} + 1}{\pi}}}{cosTheta}} \]
    5. fma-undefine97.7%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\color{blue}{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{\pi}}}{cosTheta}} \]
  11. Simplified97.7%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta}}} \]
  12. Taylor expanded in cosTheta around 0 97.7%

    \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\color{blue}{-2 \cdot \frac{cosTheta}{\pi} + \frac{1}{\pi}}}}{cosTheta}} \]
  13. Final simplification97.7%

    \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{-2 \cdot \frac{cosTheta}{\pi} + \frac{1}{\pi}}}{cosTheta}} \]
  14. Add Preprocessing

Alternative 5: 97.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{1}{1 + \frac{e^{-{cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}}} \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (/
  1.0
  (+
   1.0
   (*
    (/ (exp (- (pow cosTheta 2.0))) cosTheta)
    (sqrt (/ (+ 1.0 (* cosTheta -2.0)) PI))))))
float code(float cosTheta, float c) {
	return 1.0f / (1.0f + ((expf(-powf(cosTheta, 2.0f)) / cosTheta) * sqrtf(((1.0f + (cosTheta * -2.0f)) / ((float) M_PI)))));
}
function code(cosTheta, c)
	return Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(Float32(exp(Float32(-(cosTheta ^ Float32(2.0)))) / cosTheta) * sqrt(Float32(Float32(Float32(1.0) + Float32(cosTheta * Float32(-2.0))) / Float32(pi))))))
end
function tmp = code(cosTheta, c)
	tmp = single(1.0) / (single(1.0) + ((exp(-(cosTheta ^ single(2.0))) / cosTheta) * sqrt(((single(1.0) + (cosTheta * single(-2.0))) / single(pi)))));
end
\begin{array}{l}

\\
\frac{1}{1 + \frac{e^{-{cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}}}
\end{array}
Derivation
  1. Initial program 97.5%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. +-commutative97.5%

      \[\leadsto \frac{1}{\color{blue}{\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta} + \left(1 + c\right)}} \]
    2. fma-define97.5%

      \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)}} \]
    3. associate-*l/98.2%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\color{blue}{\frac{1 \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}}{\sqrt{\pi}}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    4. *-lft-identity98.2%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    5. associate--l-98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{\color{blue}{1 - \left(cosTheta + cosTheta\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    6. sub-neg98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{\color{blue}{1 + \left(-\left(cosTheta + cosTheta\right)\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    7. neg-mul-198.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + \color{blue}{-1 \cdot \left(cosTheta + cosTheta\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    8. distribute-lft-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + \color{blue}{\left(-1 \cdot cosTheta + -1 \cdot cosTheta\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    9. distribute-rgt-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + \color{blue}{cosTheta \cdot \left(-1 + -1\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    10. metadata-eval98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot \color{blue}{-2}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    11. distribute-lft-neg-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, e^{\color{blue}{-cosTheta \cdot cosTheta}}, 1 + c\right)} \]
    12. distribute-rgt-neg-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, e^{\color{blue}{cosTheta \cdot \left(-cosTheta\right)}}, 1 + c\right)} \]
    13. exp-prod98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, \color{blue}{{\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}}, 1 + c\right)} \]
  3. Simplified98.1%

    \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. clear-num98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{1}{\frac{cosTheta}{\sqrt{1 + cosTheta \cdot -2}}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
    2. inv-pow98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{{\left(\frac{cosTheta}{\sqrt{1 + cosTheta \cdot -2}}\right)}^{-1}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
    3. +-commutative98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{{\left(\frac{cosTheta}{\sqrt{\color{blue}{cosTheta \cdot -2 + 1}}}\right)}^{-1}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
    4. fma-define98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{{\left(\frac{cosTheta}{\sqrt{\color{blue}{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}\right)}^{-1}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  6. Applied egg-rr98.1%

    \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{{\left(\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}\right)}^{-1}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  7. Step-by-step derivation
    1. unpow-198.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{1}{\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  8. Simplified98.1%

    \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{1}{\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  9. Step-by-step derivation
    1. inv-pow98.1%

      \[\leadsto \color{blue}{{\left(\mathsf{fma}\left(\frac{\frac{1}{\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)\right)}^{-1}} \]
    2. add-sqr-sqrt97.3%

      \[\leadsto {\color{blue}{\left(\sqrt{\mathsf{fma}\left(\frac{\frac{1}{\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \cdot \sqrt{\mathsf{fma}\left(\frac{\frac{1}{\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)}\right)}}^{-1} \]
    3. unpow-prod-down97.2%

      \[\leadsto \color{blue}{{\left(\sqrt{\mathsf{fma}\left(\frac{\frac{1}{\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)}\right)}^{-1} \cdot {\left(\sqrt{\mathsf{fma}\left(\frac{\frac{1}{\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)}\right)}^{-1}} \]
  10. Applied egg-rr97.2%

    \[\leadsto \color{blue}{{\left(\sqrt{\mathsf{fma}\left(\frac{\frac{1}{cosTheta} \cdot \sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{\sqrt{\pi}}, e^{-{cosTheta}^{2}}, 1 + c\right)}\right)}^{-1} \cdot {\left(\sqrt{\mathsf{fma}\left(\frac{\frac{1}{cosTheta} \cdot \sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{\sqrt{\pi}}, e^{-{cosTheta}^{2}}, 1 + c\right)}\right)}^{-1}} \]
  11. Step-by-step derivation
    1. pow-sqr97.7%

      \[\leadsto \color{blue}{{\left(\sqrt{\mathsf{fma}\left(\frac{\frac{1}{cosTheta} \cdot \sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{\sqrt{\pi}}, e^{-{cosTheta}^{2}}, 1 + c\right)}\right)}^{\left(2 \cdot -1\right)}} \]
    2. associate-*l/97.7%

      \[\leadsto {\left(\sqrt{\mathsf{fma}\left(\frac{\color{blue}{\frac{1 \cdot \sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{cosTheta}}}{\sqrt{\pi}}, e^{-{cosTheta}^{2}}, 1 + c\right)}\right)}^{\left(2 \cdot -1\right)} \]
    3. *-lft-identity97.7%

      \[\leadsto {\left(\sqrt{\mathsf{fma}\left(\frac{\frac{\color{blue}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{-{cosTheta}^{2}}, 1 + c\right)}\right)}^{\left(2 \cdot -1\right)} \]
    4. metadata-eval97.7%

      \[\leadsto {\left(\sqrt{\mathsf{fma}\left(\frac{\frac{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{cosTheta}}{\sqrt{\pi}}, e^{-{cosTheta}^{2}}, 1 + c\right)}\right)}^{\color{blue}{-2}} \]
  12. Simplified97.7%

    \[\leadsto \color{blue}{{\left(\sqrt{\mathsf{fma}\left(\frac{\frac{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{cosTheta}}{\sqrt{\pi}}, e^{-{cosTheta}^{2}}, 1 + c\right)}\right)}^{-2}} \]
  13. Taylor expanded in c around 0 97.4%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{e^{-{cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 + -2 \cdot cosTheta}{\pi}}}} \]
  14. Final simplification97.4%

    \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 + cosTheta \cdot -2}{\pi}}} \]
  15. Add Preprocessing

Alternative 6: 95.9% accurate, 1.5× speedup?

\[\begin{array}{l} \\ cosTheta \cdot \left(\sqrt{\pi} + \left(cosTheta \cdot \pi\right) \cdot \left(-1 + \left(\sqrt{\frac{1}{\pi}} - c\right)\right)\right) \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (*
  cosTheta
  (+ (sqrt PI) (* (* cosTheta PI) (+ -1.0 (- (sqrt (/ 1.0 PI)) c))))))
float code(float cosTheta, float c) {
	return cosTheta * (sqrtf(((float) M_PI)) + ((cosTheta * ((float) M_PI)) * (-1.0f + (sqrtf((1.0f / ((float) M_PI))) - c))));
}
function code(cosTheta, c)
	return Float32(cosTheta * Float32(sqrt(Float32(pi)) + Float32(Float32(cosTheta * Float32(pi)) * Float32(Float32(-1.0) + Float32(sqrt(Float32(Float32(1.0) / Float32(pi))) - c)))))
end
function tmp = code(cosTheta, c)
	tmp = cosTheta * (sqrt(single(pi)) + ((cosTheta * single(pi)) * (single(-1.0) + (sqrt((single(1.0) / single(pi))) - c))));
end
\begin{array}{l}

\\
cosTheta \cdot \left(\sqrt{\pi} + \left(cosTheta \cdot \pi\right) \cdot \left(-1 + \left(\sqrt{\frac{1}{\pi}} - c\right)\right)\right)
\end{array}
Derivation
  1. Initial program 97.5%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. associate-+l+97.5%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(c + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}} \]
    2. +-commutative97.5%

      \[\leadsto \frac{1}{1 + \color{blue}{\left(\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta} + c\right)}} \]
    3. fma-define97.5%

      \[\leadsto \frac{1}{1 + \color{blue}{\mathsf{fma}\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}, e^{\left(-cosTheta\right) \cdot cosTheta}, c\right)}} \]
  3. Simplified98.4%

    \[\leadsto \color{blue}{\frac{1}{1 + \mathsf{fma}\left(\frac{\sqrt{1 + cosTheta \cdot -2}}{\sqrt{\pi} \cdot cosTheta}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in cosTheta around 0 96.7%

    \[\leadsto \color{blue}{cosTheta \cdot \left(\sqrt{\pi} + -1 \cdot \left(cosTheta \cdot \left(\pi \cdot \left(1 + \left(c + -1 \cdot \sqrt{\frac{1}{\pi}}\right)\right)\right)\right)\right)} \]
  6. Step-by-step derivation
    1. mul-1-neg96.7%

      \[\leadsto cosTheta \cdot \left(\sqrt{\pi} + \color{blue}{\left(-cosTheta \cdot \left(\pi \cdot \left(1 + \left(c + -1 \cdot \sqrt{\frac{1}{\pi}}\right)\right)\right)\right)}\right) \]
    2. unsub-neg96.7%

      \[\leadsto cosTheta \cdot \color{blue}{\left(\sqrt{\pi} - cosTheta \cdot \left(\pi \cdot \left(1 + \left(c + -1 \cdot \sqrt{\frac{1}{\pi}}\right)\right)\right)\right)} \]
    3. *-commutative96.7%

      \[\leadsto cosTheta \cdot \left(\sqrt{\pi} - \color{blue}{\left(\pi \cdot \left(1 + \left(c + -1 \cdot \sqrt{\frac{1}{\pi}}\right)\right)\right) \cdot cosTheta}\right) \]
    4. *-commutative96.7%

      \[\leadsto cosTheta \cdot \left(\sqrt{\pi} - \color{blue}{\left(\left(1 + \left(c + -1 \cdot \sqrt{\frac{1}{\pi}}\right)\right) \cdot \pi\right)} \cdot cosTheta\right) \]
    5. associate-*l*96.7%

      \[\leadsto cosTheta \cdot \left(\sqrt{\pi} - \color{blue}{\left(1 + \left(c + -1 \cdot \sqrt{\frac{1}{\pi}}\right)\right) \cdot \left(\pi \cdot cosTheta\right)}\right) \]
    6. mul-1-neg96.7%

      \[\leadsto cosTheta \cdot \left(\sqrt{\pi} - \left(1 + \left(c + \color{blue}{\left(-\sqrt{\frac{1}{\pi}}\right)}\right)\right) \cdot \left(\pi \cdot cosTheta\right)\right) \]
    7. unsub-neg96.7%

      \[\leadsto cosTheta \cdot \left(\sqrt{\pi} - \left(1 + \color{blue}{\left(c - \sqrt{\frac{1}{\pi}}\right)}\right) \cdot \left(\pi \cdot cosTheta\right)\right) \]
    8. *-commutative96.7%

      \[\leadsto cosTheta \cdot \left(\sqrt{\pi} - \left(1 + \left(c - \sqrt{\frac{1}{\pi}}\right)\right) \cdot \color{blue}{\left(cosTheta \cdot \pi\right)}\right) \]
  7. Simplified96.7%

    \[\leadsto \color{blue}{cosTheta \cdot \left(\sqrt{\pi} - \left(1 + \left(c - \sqrt{\frac{1}{\pi}}\right)\right) \cdot \left(cosTheta \cdot \pi\right)\right)} \]
  8. Final simplification96.7%

    \[\leadsto cosTheta \cdot \left(\sqrt{\pi} + \left(cosTheta \cdot \pi\right) \cdot \left(-1 + \left(\sqrt{\frac{1}{\pi}} - c\right)\right)\right) \]
  9. Add Preprocessing

Alternative 7: 95.7% accurate, 1.5× speedup?

\[\begin{array}{l} \\ cosTheta \cdot \left(\sqrt{\pi} + \left(cosTheta \cdot \pi\right) \cdot \left(-1 + \sqrt{\frac{1}{\pi}}\right)\right) \end{array} \]
(FPCore (cosTheta c)
 :precision binary32
 (* cosTheta (+ (sqrt PI) (* (* cosTheta PI) (+ -1.0 (sqrt (/ 1.0 PI)))))))
float code(float cosTheta, float c) {
	return cosTheta * (sqrtf(((float) M_PI)) + ((cosTheta * ((float) M_PI)) * (-1.0f + sqrtf((1.0f / ((float) M_PI))))));
}
function code(cosTheta, c)
	return Float32(cosTheta * Float32(sqrt(Float32(pi)) + Float32(Float32(cosTheta * Float32(pi)) * Float32(Float32(-1.0) + sqrt(Float32(Float32(1.0) / Float32(pi)))))))
end
function tmp = code(cosTheta, c)
	tmp = cosTheta * (sqrt(single(pi)) + ((cosTheta * single(pi)) * (single(-1.0) + sqrt((single(1.0) / single(pi))))));
end
\begin{array}{l}

\\
cosTheta \cdot \left(\sqrt{\pi} + \left(cosTheta \cdot \pi\right) \cdot \left(-1 + \sqrt{\frac{1}{\pi}}\right)\right)
\end{array}
Derivation
  1. Initial program 97.5%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. +-commutative97.5%

      \[\leadsto \frac{1}{\color{blue}{\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta} + \left(1 + c\right)}} \]
    2. fma-define97.5%

      \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)}} \]
    3. associate-*l/98.2%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\color{blue}{\frac{1 \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}}{\sqrt{\pi}}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    4. *-lft-identity98.2%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    5. associate--l-98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{\color{blue}{1 - \left(cosTheta + cosTheta\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    6. sub-neg98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{\color{blue}{1 + \left(-\left(cosTheta + cosTheta\right)\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    7. neg-mul-198.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + \color{blue}{-1 \cdot \left(cosTheta + cosTheta\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    8. distribute-lft-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + \color{blue}{\left(-1 \cdot cosTheta + -1 \cdot cosTheta\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    9. distribute-rgt-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + \color{blue}{cosTheta \cdot \left(-1 + -1\right)}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    10. metadata-eval98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot \color{blue}{-2}}}{cosTheta}}{\sqrt{\pi}}, e^{\left(-cosTheta\right) \cdot cosTheta}, 1 + c\right)} \]
    11. distribute-lft-neg-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, e^{\color{blue}{-cosTheta \cdot cosTheta}}, 1 + c\right)} \]
    12. distribute-rgt-neg-out98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, e^{\color{blue}{cosTheta \cdot \left(-cosTheta\right)}}, 1 + c\right)} \]
    13. exp-prod98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, \color{blue}{{\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}}, 1 + c\right)} \]
  3. Simplified98.1%

    \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(\frac{\frac{\sqrt{1 + cosTheta \cdot -2}}{cosTheta}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. clear-num98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{1}{\frac{cosTheta}{\sqrt{1 + cosTheta \cdot -2}}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
    2. inv-pow98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{{\left(\frac{cosTheta}{\sqrt{1 + cosTheta \cdot -2}}\right)}^{-1}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
    3. +-commutative98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{{\left(\frac{cosTheta}{\sqrt{\color{blue}{cosTheta \cdot -2 + 1}}}\right)}^{-1}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
    4. fma-define98.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{{\left(\frac{cosTheta}{\sqrt{\color{blue}{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}\right)}^{-1}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  6. Applied egg-rr98.1%

    \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{{\left(\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}\right)}^{-1}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  7. Step-by-step derivation
    1. unpow-198.1%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{1}{\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  8. Simplified98.1%

    \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{\color{blue}{\frac{1}{\frac{cosTheta}{\sqrt{\mathsf{fma}\left(cosTheta, -2, 1\right)}}}}}{\sqrt{\pi}}, {\left(e^{cosTheta}\right)}^{\left(-cosTheta\right)}, 1 + c\right)} \]
  9. Taylor expanded in c around 0 97.4%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{e^{-1 \cdot {cosTheta}^{2}}}{cosTheta} \cdot \sqrt{\frac{1 + -2 \cdot cosTheta}{\pi}}}} \]
  10. Step-by-step derivation
    1. associate-*l/97.7%

      \[\leadsto \frac{1}{1 + \color{blue}{\frac{e^{-1 \cdot {cosTheta}^{2}} \cdot \sqrt{\frac{1 + -2 \cdot cosTheta}{\pi}}}{cosTheta}}} \]
    2. neg-mul-197.7%

      \[\leadsto \frac{1}{1 + \frac{e^{\color{blue}{-{cosTheta}^{2}}} \cdot \sqrt{\frac{1 + -2 \cdot cosTheta}{\pi}}}{cosTheta}} \]
    3. +-commutative97.7%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\color{blue}{-2 \cdot cosTheta + 1}}{\pi}}}{cosTheta}} \]
    4. *-commutative97.7%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\color{blue}{cosTheta \cdot -2} + 1}{\pi}}}{cosTheta}} \]
    5. fma-undefine97.7%

      \[\leadsto \frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\color{blue}{\mathsf{fma}\left(cosTheta, -2, 1\right)}}{\pi}}}{cosTheta}} \]
  11. Simplified97.7%

    \[\leadsto \color{blue}{\frac{1}{1 + \frac{e^{-{cosTheta}^{2}} \cdot \sqrt{\frac{\mathsf{fma}\left(cosTheta, -2, 1\right)}{\pi}}}{cosTheta}}} \]
  12. Taylor expanded in cosTheta around 0 96.5%

    \[\leadsto \color{blue}{cosTheta \cdot \left(\sqrt{\pi} + -1 \cdot \left(cosTheta \cdot \left(\pi \cdot \left(1 + -1 \cdot \sqrt{\frac{1}{\pi}}\right)\right)\right)\right)} \]
  13. Step-by-step derivation
    1. mul-1-neg96.5%

      \[\leadsto cosTheta \cdot \left(\sqrt{\pi} + \color{blue}{\left(-cosTheta \cdot \left(\pi \cdot \left(1 + -1 \cdot \sqrt{\frac{1}{\pi}}\right)\right)\right)}\right) \]
    2. unsub-neg96.5%

      \[\leadsto cosTheta \cdot \color{blue}{\left(\sqrt{\pi} - cosTheta \cdot \left(\pi \cdot \left(1 + -1 \cdot \sqrt{\frac{1}{\pi}}\right)\right)\right)} \]
    3. associate-*r*96.5%

      \[\leadsto cosTheta \cdot \left(\sqrt{\pi} - \color{blue}{\left(cosTheta \cdot \pi\right) \cdot \left(1 + -1 \cdot \sqrt{\frac{1}{\pi}}\right)}\right) \]
    4. mul-1-neg96.5%

      \[\leadsto cosTheta \cdot \left(\sqrt{\pi} - \left(cosTheta \cdot \pi\right) \cdot \left(1 + \color{blue}{\left(-\sqrt{\frac{1}{\pi}}\right)}\right)\right) \]
    5. unsub-neg96.5%

      \[\leadsto cosTheta \cdot \left(\sqrt{\pi} - \left(cosTheta \cdot \pi\right) \cdot \color{blue}{\left(1 - \sqrt{\frac{1}{\pi}}\right)}\right) \]
  14. Simplified96.5%

    \[\leadsto \color{blue}{cosTheta \cdot \left(\sqrt{\pi} - \left(cosTheta \cdot \pi\right) \cdot \left(1 - \sqrt{\frac{1}{\pi}}\right)\right)} \]
  15. Final simplification96.5%

    \[\leadsto cosTheta \cdot \left(\sqrt{\pi} + \left(cosTheta \cdot \pi\right) \cdot \left(-1 + \sqrt{\frac{1}{\pi}}\right)\right) \]
  16. Add Preprocessing

Alternative 8: 93.2% accurate, 3.1× speedup?

\[\begin{array}{l} \\ cosTheta \cdot \sqrt{\pi} \end{array} \]
(FPCore (cosTheta c) :precision binary32 (* cosTheta (sqrt PI)))
float code(float cosTheta, float c) {
	return cosTheta * sqrtf(((float) M_PI));
}
function code(cosTheta, c)
	return Float32(cosTheta * sqrt(Float32(pi)))
end
function tmp = code(cosTheta, c)
	tmp = cosTheta * sqrt(single(pi));
end
\begin{array}{l}

\\
cosTheta \cdot \sqrt{\pi}
\end{array}
Derivation
  1. Initial program 97.5%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Step-by-step derivation
    1. associate-+l+97.5%

      \[\leadsto \frac{1}{\color{blue}{1 + \left(c + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}\right)}} \]
    2. +-commutative97.5%

      \[\leadsto \frac{1}{1 + \color{blue}{\left(\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta} + c\right)}} \]
    3. fma-define97.5%

      \[\leadsto \frac{1}{1 + \color{blue}{\mathsf{fma}\left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}, e^{\left(-cosTheta\right) \cdot cosTheta}, c\right)}} \]
  3. Simplified98.4%

    \[\leadsto \color{blue}{\frac{1}{1 + \mathsf{fma}\left(\frac{\sqrt{1 + cosTheta \cdot -2}}{\sqrt{\pi} \cdot cosTheta}, {\left(e^{-cosTheta}\right)}^{cosTheta}, c\right)}} \]
  4. Add Preprocessing
  5. Taylor expanded in cosTheta around 0 94.4%

    \[\leadsto \color{blue}{cosTheta \cdot \sqrt{\pi}} \]
  6. Final simplification94.4%

    \[\leadsto cosTheta \cdot \sqrt{\pi} \]
  7. Add Preprocessing

Alternative 9: 10.7% accurate, 107.3× speedup?

\[\begin{array}{l} \\ 1 - c \end{array} \]
(FPCore (cosTheta c) :precision binary32 (- 1.0 c))
float code(float cosTheta, float c) {
	return 1.0f - c;
}
real(4) function code(costheta, c)
    real(4), intent (in) :: costheta
    real(4), intent (in) :: c
    code = 1.0e0 - c
end function
function code(cosTheta, c)
	return Float32(Float32(1.0) - c)
end
function tmp = code(cosTheta, c)
	tmp = single(1.0) - c;
end
\begin{array}{l}

\\
1 - c
\end{array}
Derivation
  1. Initial program 97.5%

    \[\frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 - cosTheta\right) - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. *-un-lft-identity97.5%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\color{blue}{1 \cdot \left(1 - cosTheta\right)} - cosTheta}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    2. add-cube-cbrt97.5%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{1 \cdot \left(1 - cosTheta\right) - \color{blue}{\left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right) \cdot \sqrt[3]{cosTheta}}}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    3. prod-diff97.5%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\color{blue}{\mathsf{fma}\left(1, 1 - cosTheta, -\sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right)}}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    4. sub-neg97.5%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\mathsf{fma}\left(1, \color{blue}{1 + \left(-cosTheta\right)}, -\sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    5. add-sqr-sqrt-0.0%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\mathsf{fma}\left(1, 1 + \color{blue}{\sqrt{-cosTheta} \cdot \sqrt{-cosTheta}}, -\sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    6. sqrt-unprod93.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\mathsf{fma}\left(1, 1 + \color{blue}{\sqrt{\left(-cosTheta\right) \cdot \left(-cosTheta\right)}}, -\sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    7. sqr-neg93.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\mathsf{fma}\left(1, 1 + \sqrt{\color{blue}{cosTheta \cdot cosTheta}}, -\sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    8. sqrt-unprod93.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\mathsf{fma}\left(1, 1 + \color{blue}{\sqrt{cosTheta} \cdot \sqrt{cosTheta}}, -\sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    9. add-sqr-sqrt93.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\mathsf{fma}\left(1, 1 + \color{blue}{cosTheta}, -\sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    10. pow293.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\mathsf{fma}\left(1, 1 + cosTheta, -\sqrt[3]{cosTheta} \cdot \color{blue}{{\left(\sqrt[3]{cosTheta}\right)}^{2}}\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}, \sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    11. pow293.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\mathsf{fma}\left(1, 1 + cosTheta, -\sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, \color{blue}{{\left(\sqrt[3]{cosTheta}\right)}^{2}}, \sqrt[3]{cosTheta} \cdot \left(\sqrt[3]{cosTheta} \cdot \sqrt[3]{cosTheta}\right)\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    12. pow293.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\mathsf{fma}\left(1, 1 + cosTheta, -\sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, {\left(\sqrt[3]{cosTheta}\right)}^{2}, \sqrt[3]{cosTheta} \cdot \color{blue}{{\left(\sqrt[3]{cosTheta}\right)}^{2}}\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  4. Applied egg-rr93.1%

    \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\color{blue}{\mathsf{fma}\left(1, 1 + cosTheta, -\sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, {\left(\sqrt[3]{cosTheta}\right)}^{2}, \sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right)}}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  5. Step-by-step derivation
    1. fma-undefine93.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\color{blue}{\left(1 \cdot \left(1 + cosTheta\right) + \left(-\sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right)\right)} + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, {\left(\sqrt[3]{cosTheta}\right)}^{2}, \sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    2. *-lft-identity93.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(\color{blue}{\left(1 + cosTheta\right)} + \left(-\sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right)\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, {\left(\sqrt[3]{cosTheta}\right)}^{2}, \sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    3. associate-+l+93.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\color{blue}{\left(1 + cosTheta\right) + \left(\left(-\sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, {\left(\sqrt[3]{cosTheta}\right)}^{2}, \sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right)\right)}}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    4. metadata-eval93.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(\color{blue}{1 \cdot 1} + cosTheta\right) + \left(\left(-\sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, {\left(\sqrt[3]{cosTheta}\right)}^{2}, \sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right)\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    5. rem-square-sqrt93.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\left(1 \cdot 1 + \color{blue}{\sqrt{cosTheta} \cdot \sqrt{cosTheta}}\right) + \left(\left(-\sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, {\left(\sqrt[3]{cosTheta}\right)}^{2}, \sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right)\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    6. rem-square-sqrt93.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\color{blue}{\sqrt{1 \cdot 1 + \sqrt{cosTheta} \cdot \sqrt{cosTheta}} \cdot \sqrt{1 \cdot 1 + \sqrt{cosTheta} \cdot \sqrt{cosTheta}}} + \left(\left(-\sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, {\left(\sqrt[3]{cosTheta}\right)}^{2}, \sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right)\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    7. hypot-undefine93.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\color{blue}{\mathsf{hypot}\left(1, \sqrt{cosTheta}\right)} \cdot \sqrt{1 \cdot 1 + \sqrt{cosTheta} \cdot \sqrt{cosTheta}} + \left(\left(-\sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, {\left(\sqrt[3]{cosTheta}\right)}^{2}, \sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right)\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    8. hypot-undefine93.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\mathsf{hypot}\left(1, \sqrt{cosTheta}\right) \cdot \color{blue}{\mathsf{hypot}\left(1, \sqrt{cosTheta}\right)} + \left(\left(-\sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, {\left(\sqrt[3]{cosTheta}\right)}^{2}, \sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right)\right)}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
    9. associate-+l+93.1%

      \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\color{blue}{\left(\mathsf{hypot}\left(1, \sqrt{cosTheta}\right) \cdot \mathsf{hypot}\left(1, \sqrt{cosTheta}\right) + \left(-\sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right)\right) + \mathsf{fma}\left(-\sqrt[3]{cosTheta}, {\left(\sqrt[3]{cosTheta}\right)}^{2}, \sqrt[3]{cosTheta} \cdot {\left(\sqrt[3]{cosTheta}\right)}^{2}\right)}}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  6. Simplified93.1%

    \[\leadsto \frac{1}{\left(1 + c\right) + \left(\frac{1}{\sqrt{\pi}} \cdot \frac{\sqrt{\color{blue}{\left(\left(cosTheta + 1\right) - cosTheta\right) + 0 \cdot cosTheta}}}{cosTheta}\right) \cdot e^{\left(-cosTheta\right) \cdot cosTheta}} \]
  7. Taylor expanded in cosTheta around inf 10.2%

    \[\leadsto \color{blue}{\frac{1}{1 + c}} \]
  8. Taylor expanded in c around 0 10.2%

    \[\leadsto \color{blue}{1 + -1 \cdot c} \]
  9. Step-by-step derivation
    1. mul-1-neg10.2%

      \[\leadsto 1 + \color{blue}{\left(-c\right)} \]
    2. unsub-neg10.2%

      \[\leadsto \color{blue}{1 - c} \]
  10. Simplified10.2%

    \[\leadsto \color{blue}{1 - c} \]
  11. Final simplification10.2%

    \[\leadsto 1 - c \]
  12. Add Preprocessing

Reproduce

?
herbie shell --seed 2024067 
(FPCore (cosTheta c)
  :name "Beckmann Sample, normalization factor"
  :precision binary32
  :pre (and (and (< 0.0 cosTheta) (< cosTheta 0.9999)) (and (< -1.0 c) (< c 1.0)))
  (/ 1.0 (+ (+ 1.0 c) (* (* (/ 1.0 (sqrt PI)) (/ (sqrt (- (- 1.0 cosTheta) cosTheta)) cosTheta)) (exp (* (- cosTheta) cosTheta))))))