
(FPCore (s r) :precision binary32 (+ (/ (* 0.25 (exp (/ (- r) s))) (* (* (* 2.0 PI) s) r)) (/ (* 0.75 (exp (/ (- r) (* 3.0 s)))) (* (* (* 6.0 PI) s) r))))
float code(float s, float r) {
return ((0.25f * expf((-r / s))) / (((2.0f * ((float) M_PI)) * s) * r)) + ((0.75f * expf((-r / (3.0f * s)))) / (((6.0f * ((float) M_PI)) * s) * r));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) * exp(Float32(Float32(-r) / s))) / Float32(Float32(Float32(Float32(2.0) * Float32(pi)) * s) * r)) + Float32(Float32(Float32(0.75) * exp(Float32(Float32(-r) / Float32(Float32(3.0) * s)))) / Float32(Float32(Float32(Float32(6.0) * Float32(pi)) * s) * r))) end
function tmp = code(s, r) tmp = ((single(0.25) * exp((-r / s))) / (((single(2.0) * single(pi)) * s) * r)) + ((single(0.75) * exp((-r / (single(3.0) * s)))) / (((single(6.0) * single(pi)) * s) * r)); end
\begin{array}{l}
\\
\frac{0.25 \cdot e^{\frac{-r}{s}}}{\left(\left(2 \cdot \pi\right) \cdot s\right) \cdot r} + \frac{0.75 \cdot e^{\frac{-r}{3 \cdot s}}}{\left(\left(6 \cdot \pi\right) \cdot s\right) \cdot r}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 15 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (s r) :precision binary32 (+ (/ (* 0.25 (exp (/ (- r) s))) (* (* (* 2.0 PI) s) r)) (/ (* 0.75 (exp (/ (- r) (* 3.0 s)))) (* (* (* 6.0 PI) s) r))))
float code(float s, float r) {
return ((0.25f * expf((-r / s))) / (((2.0f * ((float) M_PI)) * s) * r)) + ((0.75f * expf((-r / (3.0f * s)))) / (((6.0f * ((float) M_PI)) * s) * r));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) * exp(Float32(Float32(-r) / s))) / Float32(Float32(Float32(Float32(2.0) * Float32(pi)) * s) * r)) + Float32(Float32(Float32(0.75) * exp(Float32(Float32(-r) / Float32(Float32(3.0) * s)))) / Float32(Float32(Float32(Float32(6.0) * Float32(pi)) * s) * r))) end
function tmp = code(s, r) tmp = ((single(0.25) * exp((-r / s))) / (((single(2.0) * single(pi)) * s) * r)) + ((single(0.75) * exp((-r / (single(3.0) * s)))) / (((single(6.0) * single(pi)) * s) * r)); end
\begin{array}{l}
\\
\frac{0.25 \cdot e^{\frac{-r}{s}}}{\left(\left(2 \cdot \pi\right) \cdot s\right) \cdot r} + \frac{0.75 \cdot e^{\frac{-r}{3 \cdot s}}}{\left(\left(6 \cdot \pi\right) \cdot s\right) \cdot r}
\end{array}
(FPCore (s r)
:precision binary32
(+
(* (/ 0.25 (* s (* 2.0 PI))) (/ (exp (/ r (- s))) r))
(*
0.75
(/
(pow E (* (/ r s) -0.3333333333333333))
(* 6.0 (expm1 (log1p (* s (* PI r)))))))))
float code(float s, float r) {
return ((0.25f / (s * (2.0f * ((float) M_PI)))) * (expf((r / -s)) / r)) + (0.75f * (powf(((float) M_E), ((r / s) * -0.3333333333333333f)) / (6.0f * expm1f(log1pf((s * (((float) M_PI) * r)))))));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) / Float32(s * Float32(Float32(2.0) * Float32(pi)))) * Float32(exp(Float32(r / Float32(-s))) / r)) + Float32(Float32(0.75) * Float32((Float32(exp(1)) ^ Float32(Float32(r / s) * Float32(-0.3333333333333333))) / Float32(Float32(6.0) * expm1(log1p(Float32(s * Float32(Float32(pi) * r)))))))) end
\begin{array}{l}
\\
\frac{0.25}{s \cdot \left(2 \cdot \pi\right)} \cdot \frac{e^{\frac{r}{-s}}}{r} + 0.75 \cdot \frac{{e}^{\left(\frac{r}{s} \cdot -0.3333333333333333\right)}}{6 \cdot \mathsf{expm1}\left(\mathsf{log1p}\left(s \cdot \left(\pi \cdot r\right)\right)\right)}
\end{array}
Initial program 99.6%
times-frac99.6%
*-commutative99.6%
distribute-frac-neg99.6%
associate-/l*99.5%
*-commutative99.5%
*-commutative99.5%
associate-*l*99.5%
Simplified99.5%
Taylor expanded in r around 0 99.5%
*-un-lft-identity99.5%
exp-prod99.5%
neg-mul-199.5%
*-commutative99.5%
times-frac99.6%
metadata-eval99.6%
add-log-exp98.0%
log-pow98.0%
pow-exp99.6%
rem-log-exp99.6%
Applied egg-rr99.6%
expm1-log1p-u99.6%
expm1-undefine23.0%
*-commutative23.0%
associate-*l*23.0%
Applied egg-rr23.0%
expm1-define99.7%
Simplified99.7%
Final simplification99.7%
(FPCore (s r)
:precision binary32
(let* ((t_0 (/ 0.125 (* s PI))))
(fma
t_0
(/ (pow (exp -0.6666666666666666) (/ (* r 0.5) s)) r)
(* t_0 (/ (exp (/ r (- s))) r)))))
float code(float s, float r) {
float t_0 = 0.125f / (s * ((float) M_PI));
return fmaf(t_0, (powf(expf(-0.6666666666666666f), ((r * 0.5f) / s)) / r), (t_0 * (expf((r / -s)) / r)));
}
function code(s, r) t_0 = Float32(Float32(0.125) / Float32(s * Float32(pi))) return fma(t_0, Float32((exp(Float32(-0.6666666666666666)) ^ Float32(Float32(r * Float32(0.5)) / s)) / r), Float32(t_0 * Float32(exp(Float32(r / Float32(-s))) / r))) end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{0.125}{s \cdot \pi}\\
\mathsf{fma}\left(t\_0, \frac{{\left(e^{-0.6666666666666666}\right)}^{\left(\frac{r \cdot 0.5}{s}\right)}}{r}, t\_0 \cdot \frac{e^{\frac{r}{-s}}}{r}\right)
\end{array}
\end{array}
Initial program 99.6%
+-commutative99.6%
times-frac99.6%
fma-define99.6%
associate-*l*99.6%
associate-/r*99.6%
metadata-eval99.6%
*-commutative99.6%
neg-mul-199.6%
times-frac99.5%
metadata-eval99.5%
times-frac99.5%
Simplified99.5%
pow-exp99.4%
sqr-pow99.4%
pow-prod-down99.4%
prod-exp99.6%
metadata-eval99.6%
div-inv99.6%
metadata-eval99.6%
Applied egg-rr99.6%
associate-*l/99.6%
Simplified99.6%
(FPCore (s r) :precision binary32 (+ (* (/ 0.25 (* s (* 2.0 PI))) (/ (exp (/ r (- s))) r)) (* 0.75 (/ (pow E (* (/ r s) -0.3333333333333333)) (* (* s r) (* PI 6.0))))))
float code(float s, float r) {
return ((0.25f / (s * (2.0f * ((float) M_PI)))) * (expf((r / -s)) / r)) + (0.75f * (powf(((float) M_E), ((r / s) * -0.3333333333333333f)) / ((s * r) * (((float) M_PI) * 6.0f))));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) / Float32(s * Float32(Float32(2.0) * Float32(pi)))) * Float32(exp(Float32(r / Float32(-s))) / r)) + Float32(Float32(0.75) * Float32((Float32(exp(1)) ^ Float32(Float32(r / s) * Float32(-0.3333333333333333))) / Float32(Float32(s * r) * Float32(Float32(pi) * Float32(6.0)))))) end
function tmp = code(s, r) tmp = ((single(0.25) / (s * (single(2.0) * single(pi)))) * (exp((r / -s)) / r)) + (single(0.75) * ((single(2.71828182845904523536) ^ ((r / s) * single(-0.3333333333333333))) / ((s * r) * (single(pi) * single(6.0))))); end
\begin{array}{l}
\\
\frac{0.25}{s \cdot \left(2 \cdot \pi\right)} \cdot \frac{e^{\frac{r}{-s}}}{r} + 0.75 \cdot \frac{{e}^{\left(\frac{r}{s} \cdot -0.3333333333333333\right)}}{\left(s \cdot r\right) \cdot \left(\pi \cdot 6\right)}
\end{array}
Initial program 99.6%
times-frac99.6%
*-commutative99.6%
distribute-frac-neg99.6%
associate-/l*99.5%
*-commutative99.5%
*-commutative99.5%
associate-*l*99.5%
Simplified99.5%
Taylor expanded in r around 0 99.5%
*-un-lft-identity99.5%
exp-prod99.5%
neg-mul-199.5%
*-commutative99.5%
times-frac99.6%
metadata-eval99.6%
add-log-exp98.0%
log-pow98.0%
pow-exp99.6%
rem-log-exp99.6%
Applied egg-rr99.6%
expm1-log1p-u99.6%
expm1-undefine23.0%
*-commutative23.0%
associate-*l*23.0%
Applied egg-rr23.0%
expm1-define99.7%
Simplified99.7%
Taylor expanded in s around 0 99.6%
*-commutative99.6%
associate-*r*99.6%
associate-*l*99.6%
Simplified99.6%
Final simplification99.6%
(FPCore (s r) :precision binary32 (+ (* (/ 0.25 (* s (* 2.0 PI))) (/ (exp (/ r (- s))) r)) (* 0.75 (/ (pow E (* (/ r s) -0.3333333333333333)) (* 6.0 (* r (* s PI)))))))
float code(float s, float r) {
return ((0.25f / (s * (2.0f * ((float) M_PI)))) * (expf((r / -s)) / r)) + (0.75f * (powf(((float) M_E), ((r / s) * -0.3333333333333333f)) / (6.0f * (r * (s * ((float) M_PI))))));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) / Float32(s * Float32(Float32(2.0) * Float32(pi)))) * Float32(exp(Float32(r / Float32(-s))) / r)) + Float32(Float32(0.75) * Float32((Float32(exp(1)) ^ Float32(Float32(r / s) * Float32(-0.3333333333333333))) / Float32(Float32(6.0) * Float32(r * Float32(s * Float32(pi))))))) end
function tmp = code(s, r) tmp = ((single(0.25) / (s * (single(2.0) * single(pi)))) * (exp((r / -s)) / r)) + (single(0.75) * ((single(2.71828182845904523536) ^ ((r / s) * single(-0.3333333333333333))) / (single(6.0) * (r * (s * single(pi)))))); end
\begin{array}{l}
\\
\frac{0.25}{s \cdot \left(2 \cdot \pi\right)} \cdot \frac{e^{\frac{r}{-s}}}{r} + 0.75 \cdot \frac{{e}^{\left(\frac{r}{s} \cdot -0.3333333333333333\right)}}{6 \cdot \left(r \cdot \left(s \cdot \pi\right)\right)}
\end{array}
Initial program 99.6%
times-frac99.6%
*-commutative99.6%
distribute-frac-neg99.6%
associate-/l*99.5%
*-commutative99.5%
*-commutative99.5%
associate-*l*99.5%
Simplified99.5%
Taylor expanded in r around 0 99.5%
*-un-lft-identity99.5%
exp-prod99.5%
neg-mul-199.5%
*-commutative99.5%
times-frac99.6%
metadata-eval99.6%
add-log-exp98.0%
log-pow98.0%
pow-exp99.6%
rem-log-exp99.6%
Applied egg-rr99.6%
Final simplification99.6%
(FPCore (s r) :precision binary32 (+ (/ (* 0.25 (exp (/ r (- s)))) (* r (* s (* 2.0 PI)))) (/ (* 0.75 (exp (/ r (* s -3.0)))) (* r (* s (* PI 6.0))))))
float code(float s, float r) {
return ((0.25f * expf((r / -s))) / (r * (s * (2.0f * ((float) M_PI))))) + ((0.75f * expf((r / (s * -3.0f)))) / (r * (s * (((float) M_PI) * 6.0f))));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) * exp(Float32(r / Float32(-s)))) / Float32(r * Float32(s * Float32(Float32(2.0) * Float32(pi))))) + Float32(Float32(Float32(0.75) * exp(Float32(r / Float32(s * Float32(-3.0))))) / Float32(r * Float32(s * Float32(Float32(pi) * Float32(6.0)))))) end
function tmp = code(s, r) tmp = ((single(0.25) * exp((r / -s))) / (r * (s * (single(2.0) * single(pi))))) + ((single(0.75) * exp((r / (s * single(-3.0))))) / (r * (s * (single(pi) * single(6.0))))); end
\begin{array}{l}
\\
\frac{0.25 \cdot e^{\frac{r}{-s}}}{r \cdot \left(s \cdot \left(2 \cdot \pi\right)\right)} + \frac{0.75 \cdot e^{\frac{r}{s \cdot -3}}}{r \cdot \left(s \cdot \left(\pi \cdot 6\right)\right)}
\end{array}
Initial program 99.6%
Taylor expanded in r around 0 99.5%
*-commutative99.5%
metadata-eval99.5%
times-frac99.6%
*-rgt-identity99.6%
Simplified99.6%
Final simplification99.6%
(FPCore (s r) :precision binary32 (* (* (/ 0.125 s) (/ 1.0 PI)) (+ (/ (exp (/ r (- s))) r) (/ (exp (/ -0.3333333333333333 (/ s r))) r))))
float code(float s, float r) {
return ((0.125f / s) * (1.0f / ((float) M_PI))) * ((expf((r / -s)) / r) + (expf((-0.3333333333333333f / (s / r))) / r));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.125) / s) * Float32(Float32(1.0) / Float32(pi))) * Float32(Float32(exp(Float32(r / Float32(-s))) / r) + Float32(exp(Float32(Float32(-0.3333333333333333) / Float32(s / r))) / r))) end
function tmp = code(s, r) tmp = ((single(0.125) / s) * (single(1.0) / single(pi))) * ((exp((r / -s)) / r) + (exp((single(-0.3333333333333333) / (s / r))) / r)); end
\begin{array}{l}
\\
\left(\frac{0.125}{s} \cdot \frac{1}{\pi}\right) \cdot \left(\frac{e^{\frac{r}{-s}}}{r} + \frac{e^{\frac{-0.3333333333333333}{\frac{s}{r}}}}{r}\right)
\end{array}
Initial program 99.6%
Simplified99.4%
Taylor expanded in r around inf 99.5%
associate-*r/99.5%
associate-*l/99.5%
associate-/r/99.5%
Simplified99.5%
associate-/r*99.5%
div-inv99.6%
Applied egg-rr99.6%
(FPCore (s r) :precision binary32 (* (/ 0.125 (* s PI)) (+ (/ (exp (/ r (- s))) r) (/ (pow E (/ (* r -0.3333333333333333) s)) r))))
float code(float s, float r) {
return (0.125f / (s * ((float) M_PI))) * ((expf((r / -s)) / r) + (powf(((float) M_E), ((r * -0.3333333333333333f) / s)) / r));
}
function code(s, r) return Float32(Float32(Float32(0.125) / Float32(s * Float32(pi))) * Float32(Float32(exp(Float32(r / Float32(-s))) / r) + Float32((Float32(exp(1)) ^ Float32(Float32(r * Float32(-0.3333333333333333)) / s)) / r))) end
function tmp = code(s, r) tmp = (single(0.125) / (s * single(pi))) * ((exp((r / -s)) / r) + ((single(2.71828182845904523536) ^ ((r * single(-0.3333333333333333)) / s)) / r)); end
\begin{array}{l}
\\
\frac{0.125}{s \cdot \pi} \cdot \left(\frac{e^{\frac{r}{-s}}}{r} + \frac{{e}^{\left(\frac{r \cdot -0.3333333333333333}{s}\right)}}{r}\right)
\end{array}
Initial program 99.6%
Simplified99.4%
Taylor expanded in r around inf 99.5%
associate-*r/99.5%
associate-*l/99.5%
associate-/r/99.5%
Simplified99.5%
*-un-lft-identity99.5%
exp-prod99.6%
associate-/r/99.6%
*-commutative99.6%
associate-/l*99.6%
Applied egg-rr99.6%
Final simplification99.6%
(FPCore (s r) :precision binary32 (* (/ 0.125 (* s PI)) (+ (/ (exp (/ r (- s))) r) (/ (exp (/ -0.3333333333333333 (/ s r))) r))))
float code(float s, float r) {
return (0.125f / (s * ((float) M_PI))) * ((expf((r / -s)) / r) + (expf((-0.3333333333333333f / (s / r))) / r));
}
function code(s, r) return Float32(Float32(Float32(0.125) / Float32(s * Float32(pi))) * Float32(Float32(exp(Float32(r / Float32(-s))) / r) + Float32(exp(Float32(Float32(-0.3333333333333333) / Float32(s / r))) / r))) end
function tmp = code(s, r) tmp = (single(0.125) / (s * single(pi))) * ((exp((r / -s)) / r) + (exp((single(-0.3333333333333333) / (s / r))) / r)); end
\begin{array}{l}
\\
\frac{0.125}{s \cdot \pi} \cdot \left(\frac{e^{\frac{r}{-s}}}{r} + \frac{e^{\frac{-0.3333333333333333}{\frac{s}{r}}}}{r}\right)
\end{array}
Initial program 99.6%
Simplified99.4%
Taylor expanded in r around inf 99.5%
associate-*r/99.5%
associate-*l/99.5%
associate-/r/99.5%
Simplified99.5%
(FPCore (s r) :precision binary32 (/ 0.25 (* s (log1p (expm1 (* PI r))))))
float code(float s, float r) {
return 0.25f / (s * log1pf(expm1f((((float) M_PI) * r))));
}
function code(s, r) return Float32(Float32(0.25) / Float32(s * log1p(expm1(Float32(Float32(pi) * r))))) end
\begin{array}{l}
\\
\frac{0.25}{s \cdot \mathsf{log1p}\left(\mathsf{expm1}\left(\pi \cdot r\right)\right)}
\end{array}
Initial program 99.6%
Simplified99.4%
Taylor expanded in r around 0 7.0%
Taylor expanded in s around 0 7.0%
mul-1-neg7.0%
Simplified7.0%
Taylor expanded in r around 0 6.8%
*-commutative6.8%
associate-*r*6.8%
Simplified6.8%
log1p-expm1-u44.8%
Applied egg-rr44.8%
(FPCore (s r) :precision binary32 (/ 0.25 (log1p (expm1 (* s (* PI r))))))
float code(float s, float r) {
return 0.25f / log1pf(expm1f((s * (((float) M_PI) * r))));
}
function code(s, r) return Float32(Float32(0.25) / log1p(expm1(Float32(s * Float32(Float32(pi) * r))))) end
\begin{array}{l}
\\
\frac{0.25}{\mathsf{log1p}\left(\mathsf{expm1}\left(s \cdot \left(\pi \cdot r\right)\right)\right)}
\end{array}
Initial program 99.6%
Simplified99.4%
Taylor expanded in r around 0 7.0%
Taylor expanded in s around inf 6.8%
log1p-expm1-u9.9%
*-commutative9.9%
associate-*l*9.9%
Applied egg-rr9.9%
(FPCore (s r) :precision binary32 (/ (+ 0.125 (* -0.125 (/ -1.0 (exp (/ r s))))) (* r (* s PI))))
float code(float s, float r) {
return (0.125f + (-0.125f * (-1.0f / expf((r / s))))) / (r * (s * ((float) M_PI)));
}
function code(s, r) return Float32(Float32(Float32(0.125) + Float32(Float32(-0.125) * Float32(Float32(-1.0) / exp(Float32(r / s))))) / Float32(r * Float32(s * Float32(pi)))) end
function tmp = code(s, r) tmp = (single(0.125) + (single(-0.125) * (single(-1.0) / exp((r / s))))) / (r * (s * single(pi))); end
\begin{array}{l}
\\
\frac{0.125 + -0.125 \cdot \frac{-1}{e^{\frac{r}{s}}}}{r \cdot \left(s \cdot \pi\right)}
\end{array}
Initial program 99.6%
Simplified99.4%
Taylor expanded in r around 0 7.0%
Taylor expanded in r around -inf 7.0%
associate-*r/7.0%
sub-neg7.0%
metadata-eval7.0%
distribute-lft-in7.0%
mul-1-neg7.0%
rec-exp7.0%
associate-*r/7.0%
metadata-eval7.0%
metadata-eval7.0%
Simplified7.0%
Final simplification7.0%
(FPCore (s r) :precision binary32 (* 0.125 (/ (+ 1.0 (exp (/ r (- s)))) (* PI (* s r)))))
float code(float s, float r) {
return 0.125f * ((1.0f + expf((r / -s))) / (((float) M_PI) * (s * r)));
}
function code(s, r) return Float32(Float32(0.125) * Float32(Float32(Float32(1.0) + exp(Float32(r / Float32(-s)))) / Float32(Float32(pi) * Float32(s * r)))) end
function tmp = code(s, r) tmp = single(0.125) * ((single(1.0) + exp((r / -s))) / (single(pi) * (s * r))); end
\begin{array}{l}
\\
0.125 \cdot \frac{1 + e^{\frac{r}{-s}}}{\pi \cdot \left(s \cdot r\right)}
\end{array}
Initial program 99.6%
Simplified99.4%
Taylor expanded in r around 0 7.0%
Taylor expanded in r around inf 7.0%
mul-1-neg7.0%
associate-*r*7.0%
Simplified7.0%
Final simplification7.0%
(FPCore (s r) :precision binary32 (* 0.125 (/ (+ 1.0 (exp (/ r (- s)))) (* r (* s PI)))))
float code(float s, float r) {
return 0.125f * ((1.0f + expf((r / -s))) / (r * (s * ((float) M_PI))));
}
function code(s, r) return Float32(Float32(0.125) * Float32(Float32(Float32(1.0) + exp(Float32(r / Float32(-s)))) / Float32(r * Float32(s * Float32(pi))))) end
function tmp = code(s, r) tmp = single(0.125) * ((single(1.0) + exp((r / -s))) / (r * (s * single(pi)))); end
\begin{array}{l}
\\
0.125 \cdot \frac{1 + e^{\frac{r}{-s}}}{r \cdot \left(s \cdot \pi\right)}
\end{array}
Initial program 99.6%
Simplified99.4%
Taylor expanded in r around 0 7.0%
Taylor expanded in s around 0 7.0%
mul-1-neg7.0%
Simplified7.0%
Taylor expanded in r around inf 7.0%
Final simplification7.0%
(FPCore (s r) :precision binary32 (/ 0.25 (* PI (* s r))))
float code(float s, float r) {
return 0.25f / (((float) M_PI) * (s * r));
}
function code(s, r) return Float32(Float32(0.25) / Float32(Float32(pi) * Float32(s * r))) end
function tmp = code(s, r) tmp = single(0.25) / (single(pi) * (s * r)); end
\begin{array}{l}
\\
\frac{0.25}{\pi \cdot \left(s \cdot r\right)}
\end{array}
Initial program 99.6%
Simplified99.4%
Taylor expanded in r around 0 7.0%
Taylor expanded in s around inf 6.8%
associate-*r*6.8%
Simplified6.8%
Final simplification6.8%
(FPCore (s r) :precision binary32 (/ 0.25 (* r (* s PI))))
float code(float s, float r) {
return 0.25f / (r * (s * ((float) M_PI)));
}
function code(s, r) return Float32(Float32(0.25) / Float32(r * Float32(s * Float32(pi)))) end
function tmp = code(s, r) tmp = single(0.25) / (r * (s * single(pi))); end
\begin{array}{l}
\\
\frac{0.25}{r \cdot \left(s \cdot \pi\right)}
\end{array}
Initial program 99.6%
Simplified99.4%
Taylor expanded in r around 0 7.0%
Taylor expanded in s around inf 6.8%
herbie shell --seed 2024098
(FPCore (s r)
:name "Disney BSSRDF, PDF of scattering profile"
:precision binary32
:pre (and (and (<= 0.0 s) (<= s 256.0)) (and (< 1e-6 r) (< r 1000000.0)))
(+ (/ (* 0.25 (exp (/ (- r) s))) (* (* (* 2.0 PI) s) r)) (/ (* 0.75 (exp (/ (- r) (* 3.0 s)))) (* (* (* 6.0 PI) s) r))))