\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}\;\frac{angle}{180} \leq -3.3897871477879634 \cdot 10^{-42}:\\
\;\;\;\;-\left(4 \cdot \frac{{\cos \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{4} \cdot {b}^{2}}{{x-scale}^{2} \cdot {y-scale}^{2}} + \left(8 \cdot \frac{{\sin \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{2} \cdot \left({b}^{2} \cdot {\cos \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{2}\right)}{{x-scale}^{2} \cdot {y-scale}^{2}} + 4 \cdot \frac{{b}^{2} \cdot {\sin \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{4}}{{x-scale}^{2} \cdot {y-scale}^{2}}\right)\right) \cdot {a}^{2}\\
\mathbf{elif}\;\frac{angle}{180} \leq 1.8020255516154388 \cdot 10^{-244}:\\
\;\;\;\;\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} \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{{\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}\\
\mathbf{else}:\\
\;\;\;\;\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 \left(b \cdot b\right)\right)}{\left(x-scale \cdot x-scale\right) \cdot \left(y-scale \cdot y-scale\right)} + \left(4 \cdot \frac{b \cdot b}{y-scale \cdot y-scale}\right) \cdot \left(\frac{{\sin \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{4}}{x-scale \cdot x-scale} + \frac{{\cos \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{4}}{x-scale \cdot x-scale}\right)\right) \cdot \left(-a \cdot a\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 (<= (/ angle 180.0) -3.3897871477879634e-42)
(-
(*
(+
(*
4.0
(/
(* (pow (cos (* 0.005555555555555556 (* angle PI))) 4.0) (pow b 2.0))
(* (pow x-scale 2.0) (pow y-scale 2.0))))
(+
(*
8.0
(/
(*
(pow (sin (* 0.005555555555555556 (* angle PI))) 2.0)
(*
(pow b 2.0)
(pow (cos (* 0.005555555555555556 (* angle PI))) 2.0)))
(* (pow x-scale 2.0) (pow y-scale 2.0))))
(*
4.0
(/
(* (pow b 2.0) (pow (sin (* 0.005555555555555556 (* angle PI))) 4.0))
(* (pow x-scale 2.0) (pow y-scale 2.0))))))
(pow a 2.0)))
(if (<= (/ angle 180.0) 1.8020255516154388e-244)
(/
(-
(*
(/
(*
(* (* 2.0 (- (pow b 2.0) (pow a 2.0))) (sin (* (/ angle 180.0) PI)))
(cos (* (/ angle 180.0) PI)))
x-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)
(*
(+
(*
8.0
(/
(*
(pow (sin (* 0.005555555555555556 (* angle PI))) 2.0)
(* (pow (cos (* 0.005555555555555556 (* angle PI))) 2.0) (* b b)))
(* (* x-scale x-scale) (* y-scale y-scale))))
(*
(* 4.0 (/ (* b b) (* y-scale y-scale)))
(+
(/
(pow (sin (* 0.005555555555555556 (* angle PI))) 4.0)
(* x-scale x-scale))
(/
(pow (cos (* 0.005555555555555556 (* angle PI))) 4.0)
(* x-scale x-scale)))))
(- (* a a))))))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 ((angle / 180.0) <= -3.3897871477879634e-42) {
tmp = -(((4.0 * ((pow(cos(0.005555555555555556 * (angle * ((double) M_PI))), 4.0) * pow(b, 2.0)) / (pow(x_45_scale, 2.0) * pow(y_45_scale, 2.0)))) + ((8.0 * ((pow(sin(0.005555555555555556 * (angle * ((double) M_PI))), 2.0) * (pow(b, 2.0) * pow(cos(0.005555555555555556 * (angle * ((double) M_PI))), 2.0))) / (pow(x_45_scale, 2.0) * pow(y_45_scale, 2.0)))) + (4.0 * ((pow(b, 2.0) * pow(sin(0.005555555555555556 * (angle * ((double) M_PI))), 4.0)) / (pow(x_45_scale, 2.0) * pow(y_45_scale, 2.0)))))) * pow(a, 2.0));
} else if ((angle / 180.0) <= 1.8020255516154388e-244) {
tmp = ((((((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) * (((((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;
} else {
tmp = ((8.0 * ((pow(sin(0.005555555555555556 * (angle * ((double) M_PI))), 2.0) * (pow(cos(0.005555555555555556 * (angle * ((double) M_PI))), 2.0) * (b * b))) / ((x_45_scale * x_45_scale) * (y_45_scale * y_45_scale)))) + ((4.0 * ((b * b) / (y_45_scale * y_45_scale))) * ((pow(sin(0.005555555555555556 * (angle * ((double) M_PI))), 4.0) / (x_45_scale * x_45_scale)) + (pow(cos(0.005555555555555556 * (angle * ((double) M_PI))), 4.0) / (x_45_scale * x_45_scale))))) * -(a * a);
}
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 (/.f64 angle 180) < -3.38978714778796341e-42Initial program 44.9
Taylor expanded around 0 39.6
if -3.38978714778796341e-42 < (/.f64 angle 180) < 1.8020255516154388e-244Initial program 36.4
rmApplied associate-*r/_binary64_2035.3
Applied associate-*l/_binary64_2135.1
Applied sub-div_binary64_8535.1
if 1.8020255516154388e-244 < (/.f64 angle 180) Initial program 42.6
Taylor expanded around 0 39.2
Simplified39.9
Final simplification38.5
herbie shell --seed 2021023
(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))))