\frac{\frac{\left(\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)}{x-scale}}{y-scale} \cdot \frac{\frac{\left(\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)}{x-scale}}{y-scale} - \left(4 \cdot \frac{\frac{{\left(a \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{x-scale}}{x-scale}\right) \cdot \frac{\frac{{\left(a \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{y-scale}}{y-scale}\begin{array}{l}
\mathbf{if}\;x-scale \leq -6.821398003204381 \cdot 10^{-145}:\\
\;\;\;\;-\frac{8 \cdot \frac{{a}^{2} \cdot \left({\sin \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{2} \cdot \left({\cos \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{2} \cdot {b}^{2}\right)\right)}{{y-scale}^{2}} + \left(4 \cdot \frac{{a}^{2} \cdot \left({b}^{2} \cdot {\sin \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{4}\right)}{{y-scale}^{2}} + 4 \cdot \frac{{a}^{2} \cdot \left({b}^{2} \cdot {\cos \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{4}\right)}{{y-scale}^{2}}\right)}{{x-scale}^{2}}\\
\mathbf{elif}\;x-scale \leq 2.3598969122018188 \cdot 10^{-119}:\\
\;\;\;\;\frac{x-scale \cdot \frac{\frac{\frac{4 \cdot \left(\left(\left(b \cdot b - a \cdot a\right) \cdot \left(\sin \left(\pi \cdot \frac{angle}{180}\right) \cdot \cos \left(\pi \cdot \frac{angle}{180}\right)\right)\right) \cdot \left(\left(b \cdot b - a \cdot a\right) \cdot \left(\sin \left(\pi \cdot \frac{angle}{180}\right) \cdot \cos \left(\pi \cdot \frac{angle}{180}\right)\right)\right)\right)}{x-scale}}{x-scale}}{y-scale} + y-scale \cdot \left(-4 \cdot \left(\frac{{\left(a \cdot \sin \left(\pi \cdot \frac{angle}{180}\right)\right)}^{2} + {\left(b \cdot \cos \left(\pi \cdot \frac{angle}{180}\right)\right)}^{2}}{x-scale} \cdot \frac{{\left(a \cdot \cos \left(\pi \cdot \frac{angle}{180}\right)\right)}^{2} + {\left(b \cdot \sin \left(\pi \cdot \frac{angle}{180}\right)\right)}^{2}}{y-scale \cdot y-scale}\right)\right)}{x-scale \cdot y-scale}\\
\mathbf{else}:\\
\;\;\;\;-{a}^{2} \cdot \left(4 \cdot \frac{{b}^{2} \cdot {\cos \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{4}}{{y-scale}^{2} \cdot {x-scale}^{2}} + \left(8 \cdot \frac{{\sin \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{2} \cdot \left({\cos \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{2} \cdot {b}^{2}\right)}{{y-scale}^{2} \cdot {x-scale}^{2}} + 4 \cdot \frac{{b}^{2} \cdot {\sin \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{4}}{{y-scale}^{2} \cdot {x-scale}^{2}}\right)\right)\\
\end{array}(FPCore (a b angle x-scale y-scale)
:precision binary64
(-
(*
(/
(/
(*
(* (* 2.0 (- (pow b 2.0) (pow a 2.0))) (sin (* (/ angle 180.0) PI)))
(cos (* (/ angle 180.0) PI)))
x-scale)
y-scale)
(/
(/
(*
(* (* 2.0 (- (pow b 2.0) (pow a 2.0))) (sin (* (/ angle 180.0) PI)))
(cos (* (/ angle 180.0) PI)))
x-scale)
y-scale))
(*
(*
4.0
(/
(/
(+
(pow (* a (sin (* (/ angle 180.0) PI))) 2.0)
(pow (* b (cos (* (/ angle 180.0) PI))) 2.0))
x-scale)
x-scale))
(/
(/
(+
(pow (* a (cos (* (/ angle 180.0) PI))) 2.0)
(pow (* b (sin (* (/ angle 180.0) PI))) 2.0))
y-scale)
y-scale))))(FPCore (a b angle x-scale y-scale)
:precision binary64
(if (<= x-scale -6.821398003204381e-145)
(-
(/
(+
(*
8.0
(/
(*
(pow a 2.0)
(*
(pow (sin (* 0.005555555555555556 (* angle PI))) 2.0)
(*
(pow (cos (* 0.005555555555555556 (* angle PI))) 2.0)
(pow b 2.0))))
(pow y-scale 2.0)))
(+
(*
4.0
(/
(*
(pow a 2.0)
(*
(pow b 2.0)
(pow (sin (* 0.005555555555555556 (* angle PI))) 4.0)))
(pow y-scale 2.0)))
(*
4.0
(/
(*
(pow a 2.0)
(*
(pow b 2.0)
(pow (cos (* 0.005555555555555556 (* angle PI))) 4.0)))
(pow y-scale 2.0)))))
(pow x-scale 2.0)))
(if (<= x-scale 2.3598969122018188e-119)
(/
(+
(*
x-scale
(/
(/
(/
(*
4.0
(*
(*
(- (* b b) (* a a))
(* (sin (* PI (/ angle 180.0))) (cos (* PI (/ angle 180.0)))))
(*
(- (* b b) (* a a))
(* (sin (* PI (/ angle 180.0))) (cos (* PI (/ angle 180.0)))))))
x-scale)
x-scale)
y-scale))
(*
y-scale
(*
-4.0
(*
(/
(+
(pow (* a (sin (* PI (/ angle 180.0)))) 2.0)
(pow (* b (cos (* PI (/ angle 180.0)))) 2.0))
x-scale)
(/
(+
(pow (* a (cos (* PI (/ angle 180.0)))) 2.0)
(pow (* b (sin (* PI (/ angle 180.0)))) 2.0))
(* y-scale y-scale))))))
(* x-scale y-scale))
(-
(*
(pow a 2.0)
(+
(*
4.0
(/
(* (pow b 2.0) (pow (cos (* 0.005555555555555556 (* angle PI))) 4.0))
(* (pow y-scale 2.0) (pow x-scale 2.0))))
(+
(*
8.0
(/
(*
(pow (sin (* 0.005555555555555556 (* angle PI))) 2.0)
(*
(pow (cos (* 0.005555555555555556 (* angle PI))) 2.0)
(pow b 2.0)))
(* (pow y-scale 2.0) (pow x-scale 2.0))))
(*
4.0
(/
(*
(pow b 2.0)
(pow (sin (* 0.005555555555555556 (* angle PI))) 4.0))
(* (pow y-scale 2.0) (pow x-scale 2.0)))))))))))double code(double a, double b, double angle, double x_45_scale, double y_45_scale) {
return ((((((2.0 * (pow(b, 2.0) - pow(a, 2.0))) * sin((angle / 180.0) * ((double) M_PI))) * cos((angle / 180.0) * ((double) M_PI))) / x_45_scale) / y_45_scale) * (((((2.0 * (pow(b, 2.0) - pow(a, 2.0))) * sin((angle / 180.0) * ((double) M_PI))) * cos((angle / 180.0) * ((double) M_PI))) / x_45_scale) / y_45_scale)) - ((4.0 * (((pow((a * sin((angle / 180.0) * ((double) M_PI))), 2.0) + pow((b * cos((angle / 180.0) * ((double) M_PI))), 2.0)) / x_45_scale) / x_45_scale)) * (((pow((a * cos((angle / 180.0) * ((double) M_PI))), 2.0) + pow((b * sin((angle / 180.0) * ((double) M_PI))), 2.0)) / y_45_scale) / y_45_scale));
}
double code(double a, double b, double angle, double x_45_scale, double y_45_scale) {
double tmp;
if (x_45_scale <= -6.821398003204381e-145) {
tmp = -(((8.0 * ((pow(a, 2.0) * (pow(sin(0.005555555555555556 * (angle * ((double) M_PI))), 2.0) * (pow(cos(0.005555555555555556 * (angle * ((double) M_PI))), 2.0) * pow(b, 2.0)))) / pow(y_45_scale, 2.0))) + ((4.0 * ((pow(a, 2.0) * (pow(b, 2.0) * pow(sin(0.005555555555555556 * (angle * ((double) M_PI))), 4.0))) / pow(y_45_scale, 2.0))) + (4.0 * ((pow(a, 2.0) * (pow(b, 2.0) * pow(cos(0.005555555555555556 * (angle * ((double) M_PI))), 4.0))) / pow(y_45_scale, 2.0))))) / pow(x_45_scale, 2.0));
} else if (x_45_scale <= 2.3598969122018188e-119) {
tmp = ((x_45_scale * ((((4.0 * ((((b * b) - (a * a)) * (sin(((double) M_PI) * (angle / 180.0)) * cos(((double) M_PI) * (angle / 180.0)))) * (((b * b) - (a * a)) * (sin(((double) M_PI) * (angle / 180.0)) * cos(((double) M_PI) * (angle / 180.0)))))) / x_45_scale) / x_45_scale) / y_45_scale)) + (y_45_scale * (-4.0 * (((pow((a * sin(((double) M_PI) * (angle / 180.0))), 2.0) + pow((b * cos(((double) M_PI) * (angle / 180.0))), 2.0)) / x_45_scale) * ((pow((a * cos(((double) M_PI) * (angle / 180.0))), 2.0) + pow((b * sin(((double) M_PI) * (angle / 180.0))), 2.0)) / (y_45_scale * y_45_scale)))))) / (x_45_scale * y_45_scale);
} else {
tmp = -(pow(a, 2.0) * ((4.0 * ((pow(b, 2.0) * pow(cos(0.005555555555555556 * (angle * ((double) M_PI))), 4.0)) / (pow(y_45_scale, 2.0) * pow(x_45_scale, 2.0)))) + ((8.0 * ((pow(sin(0.005555555555555556 * (angle * ((double) M_PI))), 2.0) * (pow(cos(0.005555555555555556 * (angle * ((double) M_PI))), 2.0) * pow(b, 2.0))) / (pow(y_45_scale, 2.0) * pow(x_45_scale, 2.0)))) + (4.0 * ((pow(b, 2.0) * pow(sin(0.005555555555555556 * (angle * ((double) M_PI))), 4.0)) / (pow(y_45_scale, 2.0) * pow(x_45_scale, 2.0)))))));
}
return tmp;
}



Bits error versus a



Bits error versus b



Bits error versus angle



Bits error versus x-scale



Bits error versus y-scale
Results
if x-scale < -6.8213980032043814e-145Initial program 39.3
Taylor expanded around 0 35.5
if -6.8213980032043814e-145 < x-scale < 2.35989691220181881e-119Initial program 50.9
rmApplied associate-*r/_binary64_2050.9
Applied associate-*l/_binary64_2148.9
Applied associate-*l/_binary64_2149.0
Applied frac-sub_binary64_8749.0
Simplified49.2
Simplified49.2
if 2.35989691220181881e-119 < x-scale Initial program 38.8
Taylor expanded around 0 35.2
Final simplification37.9
herbie shell --seed 2021013
(FPCore (a b angle x-scale y-scale)
:name "Simplification of discriminant from scale-rotated-ellipse"
:precision binary64
(- (* (/ (/ (* (* (* 2.0 (- (pow b 2.0) (pow a 2.0))) (sin (* (/ angle 180.0) PI))) (cos (* (/ angle 180.0) PI))) x-scale) y-scale) (/ (/ (* (* (* 2.0 (- (pow b 2.0) (pow a 2.0))) (sin (* (/ angle 180.0) PI))) (cos (* (/ angle 180.0) PI))) x-scale) y-scale)) (* (* 4.0 (/ (/ (+ (pow (* a (sin (* (/ angle 180.0) PI))) 2.0) (pow (* b (cos (* (/ angle 180.0) PI))) 2.0)) x-scale) x-scale)) (/ (/ (+ (pow (* a (cos (* (/ angle 180.0) PI))) 2.0) (pow (* b (sin (* (/ angle 180.0) PI))) 2.0)) y-scale) y-scale))))