Simplification of discriminant from scale-rotated-ellipse

Percentage Accurate: 25.3% → 77.6%
Time: 1.8min
Alternatives: 4
Speedup: 2485.0×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{angle}{180} \cdot \pi\\ t_1 := \sin t_0\\ t_2 := \cos t_0\\ t_3 := \frac{\frac{\left(\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot t_1\right) \cdot t_2}{x-scale}}{y-scale}\\ t_3 \cdot t_3 - \left(4 \cdot \frac{\frac{{\left(a \cdot t_1\right)}^{2} + {\left(b \cdot t_2\right)}^{2}}{x-scale}}{x-scale}\right) \cdot \frac{\frac{{\left(a \cdot t_2\right)}^{2} + {\left(b \cdot t_1\right)}^{2}}{y-scale}}{y-scale} \end{array} \end{array} \]
(FPCore (a b angle x-scale y-scale)
 :precision binary64
 (let* ((t_0 (* (/ angle 180.0) PI))
        (t_1 (sin t_0))
        (t_2 (cos t_0))
        (t_3
         (/
          (/ (* (* (* 2.0 (- (pow b 2.0) (pow a 2.0))) t_1) t_2) x-scale)
          y-scale)))
   (-
    (* t_3 t_3)
    (*
     (*
      4.0
      (/ (/ (+ (pow (* a t_1) 2.0) (pow (* b t_2) 2.0)) x-scale) x-scale))
     (/ (/ (+ (pow (* a t_2) 2.0) (pow (* b t_1) 2.0)) y-scale) y-scale)))))
double code(double a, double b, double angle, double x_45_scale, double y_45_scale) {
	double t_0 = (angle / 180.0) * ((double) M_PI);
	double t_1 = sin(t_0);
	double t_2 = cos(t_0);
	double t_3 = ((((2.0 * (pow(b, 2.0) - pow(a, 2.0))) * t_1) * t_2) / x_45_scale) / y_45_scale;
	return (t_3 * t_3) - ((4.0 * (((pow((a * t_1), 2.0) + pow((b * t_2), 2.0)) / x_45_scale) / x_45_scale)) * (((pow((a * t_2), 2.0) + pow((b * t_1), 2.0)) / y_45_scale) / y_45_scale));
}
public static double code(double a, double b, double angle, double x_45_scale, double y_45_scale) {
	double t_0 = (angle / 180.0) * Math.PI;
	double t_1 = Math.sin(t_0);
	double t_2 = Math.cos(t_0);
	double t_3 = ((((2.0 * (Math.pow(b, 2.0) - Math.pow(a, 2.0))) * t_1) * t_2) / x_45_scale) / y_45_scale;
	return (t_3 * t_3) - ((4.0 * (((Math.pow((a * t_1), 2.0) + Math.pow((b * t_2), 2.0)) / x_45_scale) / x_45_scale)) * (((Math.pow((a * t_2), 2.0) + Math.pow((b * t_1), 2.0)) / y_45_scale) / y_45_scale));
}
def code(a, b, angle, x_45_scale, y_45_scale):
	t_0 = (angle / 180.0) * math.pi
	t_1 = math.sin(t_0)
	t_2 = math.cos(t_0)
	t_3 = ((((2.0 * (math.pow(b, 2.0) - math.pow(a, 2.0))) * t_1) * t_2) / x_45_scale) / y_45_scale
	return (t_3 * t_3) - ((4.0 * (((math.pow((a * t_1), 2.0) + math.pow((b * t_2), 2.0)) / x_45_scale) / x_45_scale)) * (((math.pow((a * t_2), 2.0) + math.pow((b * t_1), 2.0)) / y_45_scale) / y_45_scale))
function code(a, b, angle, x_45_scale, y_45_scale)
	t_0 = Float64(Float64(angle / 180.0) * pi)
	t_1 = sin(t_0)
	t_2 = cos(t_0)
	t_3 = Float64(Float64(Float64(Float64(Float64(2.0 * Float64((b ^ 2.0) - (a ^ 2.0))) * t_1) * t_2) / x_45_scale) / y_45_scale)
	return Float64(Float64(t_3 * t_3) - Float64(Float64(4.0 * Float64(Float64(Float64((Float64(a * t_1) ^ 2.0) + (Float64(b * t_2) ^ 2.0)) / x_45_scale) / x_45_scale)) * Float64(Float64(Float64((Float64(a * t_2) ^ 2.0) + (Float64(b * t_1) ^ 2.0)) / y_45_scale) / y_45_scale)))
end
function tmp = code(a, b, angle, x_45_scale, y_45_scale)
	t_0 = (angle / 180.0) * pi;
	t_1 = sin(t_0);
	t_2 = cos(t_0);
	t_3 = ((((2.0 * ((b ^ 2.0) - (a ^ 2.0))) * t_1) * t_2) / x_45_scale) / y_45_scale;
	tmp = (t_3 * t_3) - ((4.0 * (((((a * t_1) ^ 2.0) + ((b * t_2) ^ 2.0)) / x_45_scale) / x_45_scale)) * (((((a * t_2) ^ 2.0) + ((b * t_1) ^ 2.0)) / y_45_scale) / y_45_scale));
end
code[a_, b_, angle_, x$45$scale_, y$45$scale_] := Block[{t$95$0 = N[(N[(angle / 180.0), $MachinePrecision] * Pi), $MachinePrecision]}, Block[{t$95$1 = N[Sin[t$95$0], $MachinePrecision]}, Block[{t$95$2 = N[Cos[t$95$0], $MachinePrecision]}, Block[{t$95$3 = N[(N[(N[(N[(N[(2.0 * N[(N[Power[b, 2.0], $MachinePrecision] - N[Power[a, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * t$95$1), $MachinePrecision] * t$95$2), $MachinePrecision] / x$45$scale), $MachinePrecision] / y$45$scale), $MachinePrecision]}, N[(N[(t$95$3 * t$95$3), $MachinePrecision] - N[(N[(4.0 * N[(N[(N[(N[Power[N[(a * t$95$1), $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[(b * t$95$2), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] / x$45$scale), $MachinePrecision] / x$45$scale), $MachinePrecision]), $MachinePrecision] * N[(N[(N[(N[Power[N[(a * t$95$2), $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[(b * t$95$1), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] / y$45$scale), $MachinePrecision] / y$45$scale), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{angle}{180} \cdot \pi\\
t_1 := \sin t_0\\
t_2 := \cos t_0\\
t_3 := \frac{\frac{\left(\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot t_1\right) \cdot t_2}{x-scale}}{y-scale}\\
t_3 \cdot t_3 - \left(4 \cdot \frac{\frac{{\left(a \cdot t_1\right)}^{2} + {\left(b \cdot t_2\right)}^{2}}{x-scale}}{x-scale}\right) \cdot \frac{\frac{{\left(a \cdot t_2\right)}^{2} + {\left(b \cdot t_1\right)}^{2}}{y-scale}}{y-scale}
\end{array}
\end{array}

Sampling outcomes in binary64 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 4 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: 25.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{angle}{180} \cdot \pi\\ t_1 := \sin t_0\\ t_2 := \cos t_0\\ t_3 := \frac{\frac{\left(\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot t_1\right) \cdot t_2}{x-scale}}{y-scale}\\ t_3 \cdot t_3 - \left(4 \cdot \frac{\frac{{\left(a \cdot t_1\right)}^{2} + {\left(b \cdot t_2\right)}^{2}}{x-scale}}{x-scale}\right) \cdot \frac{\frac{{\left(a \cdot t_2\right)}^{2} + {\left(b \cdot t_1\right)}^{2}}{y-scale}}{y-scale} \end{array} \end{array} \]
(FPCore (a b angle x-scale y-scale)
 :precision binary64
 (let* ((t_0 (* (/ angle 180.0) PI))
        (t_1 (sin t_0))
        (t_2 (cos t_0))
        (t_3
         (/
          (/ (* (* (* 2.0 (- (pow b 2.0) (pow a 2.0))) t_1) t_2) x-scale)
          y-scale)))
   (-
    (* t_3 t_3)
    (*
     (*
      4.0
      (/ (/ (+ (pow (* a t_1) 2.0) (pow (* b t_2) 2.0)) x-scale) x-scale))
     (/ (/ (+ (pow (* a t_2) 2.0) (pow (* b t_1) 2.0)) y-scale) y-scale)))))
double code(double a, double b, double angle, double x_45_scale, double y_45_scale) {
	double t_0 = (angle / 180.0) * ((double) M_PI);
	double t_1 = sin(t_0);
	double t_2 = cos(t_0);
	double t_3 = ((((2.0 * (pow(b, 2.0) - pow(a, 2.0))) * t_1) * t_2) / x_45_scale) / y_45_scale;
	return (t_3 * t_3) - ((4.0 * (((pow((a * t_1), 2.0) + pow((b * t_2), 2.0)) / x_45_scale) / x_45_scale)) * (((pow((a * t_2), 2.0) + pow((b * t_1), 2.0)) / y_45_scale) / y_45_scale));
}
public static double code(double a, double b, double angle, double x_45_scale, double y_45_scale) {
	double t_0 = (angle / 180.0) * Math.PI;
	double t_1 = Math.sin(t_0);
	double t_2 = Math.cos(t_0);
	double t_3 = ((((2.0 * (Math.pow(b, 2.0) - Math.pow(a, 2.0))) * t_1) * t_2) / x_45_scale) / y_45_scale;
	return (t_3 * t_3) - ((4.0 * (((Math.pow((a * t_1), 2.0) + Math.pow((b * t_2), 2.0)) / x_45_scale) / x_45_scale)) * (((Math.pow((a * t_2), 2.0) + Math.pow((b * t_1), 2.0)) / y_45_scale) / y_45_scale));
}
def code(a, b, angle, x_45_scale, y_45_scale):
	t_0 = (angle / 180.0) * math.pi
	t_1 = math.sin(t_0)
	t_2 = math.cos(t_0)
	t_3 = ((((2.0 * (math.pow(b, 2.0) - math.pow(a, 2.0))) * t_1) * t_2) / x_45_scale) / y_45_scale
	return (t_3 * t_3) - ((4.0 * (((math.pow((a * t_1), 2.0) + math.pow((b * t_2), 2.0)) / x_45_scale) / x_45_scale)) * (((math.pow((a * t_2), 2.0) + math.pow((b * t_1), 2.0)) / y_45_scale) / y_45_scale))
function code(a, b, angle, x_45_scale, y_45_scale)
	t_0 = Float64(Float64(angle / 180.0) * pi)
	t_1 = sin(t_0)
	t_2 = cos(t_0)
	t_3 = Float64(Float64(Float64(Float64(Float64(2.0 * Float64((b ^ 2.0) - (a ^ 2.0))) * t_1) * t_2) / x_45_scale) / y_45_scale)
	return Float64(Float64(t_3 * t_3) - Float64(Float64(4.0 * Float64(Float64(Float64((Float64(a * t_1) ^ 2.0) + (Float64(b * t_2) ^ 2.0)) / x_45_scale) / x_45_scale)) * Float64(Float64(Float64((Float64(a * t_2) ^ 2.0) + (Float64(b * t_1) ^ 2.0)) / y_45_scale) / y_45_scale)))
end
function tmp = code(a, b, angle, x_45_scale, y_45_scale)
	t_0 = (angle / 180.0) * pi;
	t_1 = sin(t_0);
	t_2 = cos(t_0);
	t_3 = ((((2.0 * ((b ^ 2.0) - (a ^ 2.0))) * t_1) * t_2) / x_45_scale) / y_45_scale;
	tmp = (t_3 * t_3) - ((4.0 * (((((a * t_1) ^ 2.0) + ((b * t_2) ^ 2.0)) / x_45_scale) / x_45_scale)) * (((((a * t_2) ^ 2.0) + ((b * t_1) ^ 2.0)) / y_45_scale) / y_45_scale));
end
code[a_, b_, angle_, x$45$scale_, y$45$scale_] := Block[{t$95$0 = N[(N[(angle / 180.0), $MachinePrecision] * Pi), $MachinePrecision]}, Block[{t$95$1 = N[Sin[t$95$0], $MachinePrecision]}, Block[{t$95$2 = N[Cos[t$95$0], $MachinePrecision]}, Block[{t$95$3 = N[(N[(N[(N[(N[(2.0 * N[(N[Power[b, 2.0], $MachinePrecision] - N[Power[a, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * t$95$1), $MachinePrecision] * t$95$2), $MachinePrecision] / x$45$scale), $MachinePrecision] / y$45$scale), $MachinePrecision]}, N[(N[(t$95$3 * t$95$3), $MachinePrecision] - N[(N[(4.0 * N[(N[(N[(N[Power[N[(a * t$95$1), $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[(b * t$95$2), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] / x$45$scale), $MachinePrecision] / x$45$scale), $MachinePrecision]), $MachinePrecision] * N[(N[(N[(N[Power[N[(a * t$95$2), $MachinePrecision], 2.0], $MachinePrecision] + N[Power[N[(b * t$95$1), $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] / y$45$scale), $MachinePrecision] / y$45$scale), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{angle}{180} \cdot \pi\\
t_1 := \sin t_0\\
t_2 := \cos t_0\\
t_3 := \frac{\frac{\left(\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot t_1\right) \cdot t_2}{x-scale}}{y-scale}\\
t_3 \cdot t_3 - \left(4 \cdot \frac{\frac{{\left(a \cdot t_1\right)}^{2} + {\left(b \cdot t_2\right)}^{2}}{x-scale}}{x-scale}\right) \cdot \frac{\frac{{\left(a \cdot t_2\right)}^{2} + {\left(b \cdot t_1\right)}^{2}}{y-scale}}{y-scale}
\end{array}
\end{array}

Alternative 1: 77.6% accurate, 21.8× speedup?

\[\begin{array}{l} \\ \left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \left({\left(x-scale \cdot y-scale\right)}^{-2} \cdot -4\right) \end{array} \]
(FPCore (a b angle x-scale y-scale)
 :precision binary64
 (* (* (* a b) (* a b)) (* (pow (* x-scale y-scale) -2.0) -4.0)))
double code(double a, double b, double angle, double x_45_scale, double y_45_scale) {
	return ((a * b) * (a * b)) * (pow((x_45_scale * y_45_scale), -2.0) * -4.0);
}
real(8) function code(a, b, angle, x_45scale, y_45scale)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: angle
    real(8), intent (in) :: x_45scale
    real(8), intent (in) :: y_45scale
    code = ((a * b) * (a * b)) * (((x_45scale * y_45scale) ** (-2.0d0)) * (-4.0d0))
end function
public static double code(double a, double b, double angle, double x_45_scale, double y_45_scale) {
	return ((a * b) * (a * b)) * (Math.pow((x_45_scale * y_45_scale), -2.0) * -4.0);
}
def code(a, b, angle, x_45_scale, y_45_scale):
	return ((a * b) * (a * b)) * (math.pow((x_45_scale * y_45_scale), -2.0) * -4.0)
function code(a, b, angle, x_45_scale, y_45_scale)
	return Float64(Float64(Float64(a * b) * Float64(a * b)) * Float64((Float64(x_45_scale * y_45_scale) ^ -2.0) * -4.0))
end
function tmp = code(a, b, angle, x_45_scale, y_45_scale)
	tmp = ((a * b) * (a * b)) * (((x_45_scale * y_45_scale) ^ -2.0) * -4.0);
end
code[a_, b_, angle_, x$45$scale_, y$45$scale_] := N[(N[(N[(a * b), $MachinePrecision] * N[(a * b), $MachinePrecision]), $MachinePrecision] * N[(N[Power[N[(x$45$scale * y$45$scale), $MachinePrecision], -2.0], $MachinePrecision] * -4.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \left({\left(x-scale \cdot y-scale\right)}^{-2} \cdot -4\right)
\end{array}
Derivation
  1. Initial program 22.6%

    \[\frac{\frac{\left(\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)}{x-scale}}{y-scale} \cdot \frac{\frac{\left(\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)}{x-scale}}{y-scale} - \left(4 \cdot \frac{\frac{{\left(a \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{x-scale}}{x-scale}\right) \cdot \frac{\frac{{\left(a \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{y-scale}}{y-scale} \]
  2. Simplified20.5%

    \[\leadsto \color{blue}{\frac{\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \left(\sin \left(\frac{angle}{180} \cdot \pi\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}{y-scale \cdot x-scale} \cdot \frac{\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \left(\sin \left(\frac{angle}{180} \cdot \pi\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}{y-scale \cdot x-scale} - 4 \cdot \left(\frac{{\left(a \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{{x-scale}^{2}} \cdot \frac{{\left(a \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{{y-scale}^{2}}\right)} \]
  3. Taylor expanded in angle around 0 53.5%

    \[\leadsto \color{blue}{-4 \cdot \frac{{a}^{2} \cdot {b}^{2}}{{x-scale}^{2} \cdot {y-scale}^{2}}} \]
  4. Step-by-step derivation
    1. associate-*r/53.5%

      \[\leadsto \color{blue}{\frac{-4 \cdot \left({a}^{2} \cdot {b}^{2}\right)}{{x-scale}^{2} \cdot {y-scale}^{2}}} \]
    2. *-commutative53.5%

      \[\leadsto \frac{-4 \cdot \color{blue}{\left({b}^{2} \cdot {a}^{2}\right)}}{{x-scale}^{2} \cdot {y-scale}^{2}} \]
    3. unpow253.5%

      \[\leadsto \frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{\color{blue}{\left(x-scale \cdot x-scale\right)} \cdot {y-scale}^{2}} \]
    4. unpow253.5%

      \[\leadsto \frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{\left(x-scale \cdot x-scale\right) \cdot \color{blue}{\left(y-scale \cdot y-scale\right)}} \]
    5. swap-sqr66.4%

      \[\leadsto \frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{\color{blue}{\left(x-scale \cdot y-scale\right) \cdot \left(x-scale \cdot y-scale\right)}} \]
    6. unpow266.4%

      \[\leadsto \frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{\color{blue}{{\left(x-scale \cdot y-scale\right)}^{2}}} \]
  5. Simplified66.4%

    \[\leadsto \color{blue}{\frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{{\left(x-scale \cdot y-scale\right)}^{2}}} \]
  6. Step-by-step derivation
    1. expm1-log1p-u28.0%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{{\left(x-scale \cdot y-scale\right)}^{2}}\right)\right)} \]
    2. expm1-udef23.8%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{{\left(x-scale \cdot y-scale\right)}^{2}}\right)} - 1} \]
    3. div-inv23.8%

      \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{\left(-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)\right) \cdot \frac{1}{{\left(x-scale \cdot y-scale\right)}^{2}}}\right)} - 1 \]
    4. pow-prod-down28.4%

      \[\leadsto e^{\mathsf{log1p}\left(\left(-4 \cdot \color{blue}{{\left(b \cdot a\right)}^{2}}\right) \cdot \frac{1}{{\left(x-scale \cdot y-scale\right)}^{2}}\right)} - 1 \]
    5. *-commutative28.4%

      \[\leadsto e^{\mathsf{log1p}\left(\left(-4 \cdot {\left(b \cdot a\right)}^{2}\right) \cdot \frac{1}{{\color{blue}{\left(y-scale \cdot x-scale\right)}}^{2}}\right)} - 1 \]
    6. pow-flip28.4%

      \[\leadsto e^{\mathsf{log1p}\left(\left(-4 \cdot {\left(b \cdot a\right)}^{2}\right) \cdot \color{blue}{{\left(y-scale \cdot x-scale\right)}^{\left(-2\right)}}\right)} - 1 \]
    7. *-commutative28.4%

      \[\leadsto e^{\mathsf{log1p}\left(\left(-4 \cdot {\left(b \cdot a\right)}^{2}\right) \cdot {\color{blue}{\left(x-scale \cdot y-scale\right)}}^{\left(-2\right)}\right)} - 1 \]
    8. metadata-eval28.4%

      \[\leadsto e^{\mathsf{log1p}\left(\left(-4 \cdot {\left(b \cdot a\right)}^{2}\right) \cdot {\left(x-scale \cdot y-scale\right)}^{\color{blue}{-2}}\right)} - 1 \]
  7. Applied egg-rr28.4%

    \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\left(-4 \cdot {\left(b \cdot a\right)}^{2}\right) \cdot {\left(x-scale \cdot y-scale\right)}^{-2}\right)} - 1} \]
  8. Step-by-step derivation
    1. expm1-def36.4%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\left(-4 \cdot {\left(b \cdot a\right)}^{2}\right) \cdot {\left(x-scale \cdot y-scale\right)}^{-2}\right)\right)} \]
    2. expm1-log1p83.0%

      \[\leadsto \color{blue}{\left(-4 \cdot {\left(b \cdot a\right)}^{2}\right) \cdot {\left(x-scale \cdot y-scale\right)}^{-2}} \]
    3. associate-*r*83.0%

      \[\leadsto \color{blue}{-4 \cdot \left({\left(b \cdot a\right)}^{2} \cdot {\left(x-scale \cdot y-scale\right)}^{-2}\right)} \]
    4. *-commutative83.0%

      \[\leadsto \color{blue}{\left({\left(b \cdot a\right)}^{2} \cdot {\left(x-scale \cdot y-scale\right)}^{-2}\right) \cdot -4} \]
    5. associate-*l*83.0%

      \[\leadsto \color{blue}{{\left(b \cdot a\right)}^{2} \cdot \left({\left(x-scale \cdot y-scale\right)}^{-2} \cdot -4\right)} \]
    6. *-commutative83.0%

      \[\leadsto {\color{blue}{\left(a \cdot b\right)}}^{2} \cdot \left({\left(x-scale \cdot y-scale\right)}^{-2} \cdot -4\right) \]
  9. Simplified83.0%

    \[\leadsto \color{blue}{{\left(a \cdot b\right)}^{2} \cdot \left({\left(x-scale \cdot y-scale\right)}^{-2} \cdot -4\right)} \]
  10. Step-by-step derivation
    1. unpow283.0%

      \[\leadsto \color{blue}{\left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right)} \cdot \left({\left(x-scale \cdot y-scale\right)}^{-2} \cdot -4\right) \]
  11. Applied egg-rr83.0%

    \[\leadsto \color{blue}{\left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right)} \cdot \left({\left(x-scale \cdot y-scale\right)}^{-2} \cdot -4\right) \]
  12. Final simplification83.0%

    \[\leadsto \left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \left({\left(x-scale \cdot y-scale\right)}^{-2} \cdot -4\right) \]

Alternative 2: 77.6% accurate, 118.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{x-scale \cdot y-scale}\\ \left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \left(-4 \cdot \left(t_0 \cdot t_0\right)\right) \end{array} \end{array} \]
(FPCore (a b angle x-scale y-scale)
 :precision binary64
 (let* ((t_0 (/ 1.0 (* x-scale y-scale))))
   (* (* (* a b) (* a b)) (* -4.0 (* t_0 t_0)))))
double code(double a, double b, double angle, double x_45_scale, double y_45_scale) {
	double t_0 = 1.0 / (x_45_scale * y_45_scale);
	return ((a * b) * (a * b)) * (-4.0 * (t_0 * t_0));
}
real(8) function code(a, b, angle, x_45scale, y_45scale)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: angle
    real(8), intent (in) :: x_45scale
    real(8), intent (in) :: y_45scale
    real(8) :: t_0
    t_0 = 1.0d0 / (x_45scale * y_45scale)
    code = ((a * b) * (a * b)) * ((-4.0d0) * (t_0 * t_0))
end function
public static double code(double a, double b, double angle, double x_45_scale, double y_45_scale) {
	double t_0 = 1.0 / (x_45_scale * y_45_scale);
	return ((a * b) * (a * b)) * (-4.0 * (t_0 * t_0));
}
def code(a, b, angle, x_45_scale, y_45_scale):
	t_0 = 1.0 / (x_45_scale * y_45_scale)
	return ((a * b) * (a * b)) * (-4.0 * (t_0 * t_0))
function code(a, b, angle, x_45_scale, y_45_scale)
	t_0 = Float64(1.0 / Float64(x_45_scale * y_45_scale))
	return Float64(Float64(Float64(a * b) * Float64(a * b)) * Float64(-4.0 * Float64(t_0 * t_0)))
end
function tmp = code(a, b, angle, x_45_scale, y_45_scale)
	t_0 = 1.0 / (x_45_scale * y_45_scale);
	tmp = ((a * b) * (a * b)) * (-4.0 * (t_0 * t_0));
end
code[a_, b_, angle_, x$45$scale_, y$45$scale_] := Block[{t$95$0 = N[(1.0 / N[(x$45$scale * y$45$scale), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(a * b), $MachinePrecision] * N[(a * b), $MachinePrecision]), $MachinePrecision] * N[(-4.0 * N[(t$95$0 * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1}{x-scale \cdot y-scale}\\
\left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \left(-4 \cdot \left(t_0 \cdot t_0\right)\right)
\end{array}
\end{array}
Derivation
  1. Initial program 22.6%

    \[\frac{\frac{\left(\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)}{x-scale}}{y-scale} \cdot \frac{\frac{\left(\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)}{x-scale}}{y-scale} - \left(4 \cdot \frac{\frac{{\left(a \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{x-scale}}{x-scale}\right) \cdot \frac{\frac{{\left(a \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{y-scale}}{y-scale} \]
  2. Simplified20.5%

    \[\leadsto \color{blue}{\frac{\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \left(\sin \left(\frac{angle}{180} \cdot \pi\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}{y-scale \cdot x-scale} \cdot \frac{\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \left(\sin \left(\frac{angle}{180} \cdot \pi\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}{y-scale \cdot x-scale} - 4 \cdot \left(\frac{{\left(a \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{{x-scale}^{2}} \cdot \frac{{\left(a \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{{y-scale}^{2}}\right)} \]
  3. Taylor expanded in angle around 0 53.5%

    \[\leadsto \color{blue}{-4 \cdot \frac{{a}^{2} \cdot {b}^{2}}{{x-scale}^{2} \cdot {y-scale}^{2}}} \]
  4. Step-by-step derivation
    1. associate-*r/53.5%

      \[\leadsto \color{blue}{\frac{-4 \cdot \left({a}^{2} \cdot {b}^{2}\right)}{{x-scale}^{2} \cdot {y-scale}^{2}}} \]
    2. *-commutative53.5%

      \[\leadsto \frac{-4 \cdot \color{blue}{\left({b}^{2} \cdot {a}^{2}\right)}}{{x-scale}^{2} \cdot {y-scale}^{2}} \]
    3. unpow253.5%

      \[\leadsto \frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{\color{blue}{\left(x-scale \cdot x-scale\right)} \cdot {y-scale}^{2}} \]
    4. unpow253.5%

      \[\leadsto \frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{\left(x-scale \cdot x-scale\right) \cdot \color{blue}{\left(y-scale \cdot y-scale\right)}} \]
    5. swap-sqr66.4%

      \[\leadsto \frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{\color{blue}{\left(x-scale \cdot y-scale\right) \cdot \left(x-scale \cdot y-scale\right)}} \]
    6. unpow266.4%

      \[\leadsto \frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{\color{blue}{{\left(x-scale \cdot y-scale\right)}^{2}}} \]
  5. Simplified66.4%

    \[\leadsto \color{blue}{\frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{{\left(x-scale \cdot y-scale\right)}^{2}}} \]
  6. Step-by-step derivation
    1. expm1-log1p-u28.0%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{{\left(x-scale \cdot y-scale\right)}^{2}}\right)\right)} \]
    2. expm1-udef23.8%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{{\left(x-scale \cdot y-scale\right)}^{2}}\right)} - 1} \]
    3. div-inv23.8%

      \[\leadsto e^{\mathsf{log1p}\left(\color{blue}{\left(-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)\right) \cdot \frac{1}{{\left(x-scale \cdot y-scale\right)}^{2}}}\right)} - 1 \]
    4. pow-prod-down28.4%

      \[\leadsto e^{\mathsf{log1p}\left(\left(-4 \cdot \color{blue}{{\left(b \cdot a\right)}^{2}}\right) \cdot \frac{1}{{\left(x-scale \cdot y-scale\right)}^{2}}\right)} - 1 \]
    5. *-commutative28.4%

      \[\leadsto e^{\mathsf{log1p}\left(\left(-4 \cdot {\left(b \cdot a\right)}^{2}\right) \cdot \frac{1}{{\color{blue}{\left(y-scale \cdot x-scale\right)}}^{2}}\right)} - 1 \]
    6. pow-flip28.4%

      \[\leadsto e^{\mathsf{log1p}\left(\left(-4 \cdot {\left(b \cdot a\right)}^{2}\right) \cdot \color{blue}{{\left(y-scale \cdot x-scale\right)}^{\left(-2\right)}}\right)} - 1 \]
    7. *-commutative28.4%

      \[\leadsto e^{\mathsf{log1p}\left(\left(-4 \cdot {\left(b \cdot a\right)}^{2}\right) \cdot {\color{blue}{\left(x-scale \cdot y-scale\right)}}^{\left(-2\right)}\right)} - 1 \]
    8. metadata-eval28.4%

      \[\leadsto e^{\mathsf{log1p}\left(\left(-4 \cdot {\left(b \cdot a\right)}^{2}\right) \cdot {\left(x-scale \cdot y-scale\right)}^{\color{blue}{-2}}\right)} - 1 \]
  7. Applied egg-rr28.4%

    \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(\left(-4 \cdot {\left(b \cdot a\right)}^{2}\right) \cdot {\left(x-scale \cdot y-scale\right)}^{-2}\right)} - 1} \]
  8. Step-by-step derivation
    1. expm1-def36.4%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\left(-4 \cdot {\left(b \cdot a\right)}^{2}\right) \cdot {\left(x-scale \cdot y-scale\right)}^{-2}\right)\right)} \]
    2. expm1-log1p83.0%

      \[\leadsto \color{blue}{\left(-4 \cdot {\left(b \cdot a\right)}^{2}\right) \cdot {\left(x-scale \cdot y-scale\right)}^{-2}} \]
    3. associate-*r*83.0%

      \[\leadsto \color{blue}{-4 \cdot \left({\left(b \cdot a\right)}^{2} \cdot {\left(x-scale \cdot y-scale\right)}^{-2}\right)} \]
    4. *-commutative83.0%

      \[\leadsto \color{blue}{\left({\left(b \cdot a\right)}^{2} \cdot {\left(x-scale \cdot y-scale\right)}^{-2}\right) \cdot -4} \]
    5. associate-*l*83.0%

      \[\leadsto \color{blue}{{\left(b \cdot a\right)}^{2} \cdot \left({\left(x-scale \cdot y-scale\right)}^{-2} \cdot -4\right)} \]
    6. *-commutative83.0%

      \[\leadsto {\color{blue}{\left(a \cdot b\right)}}^{2} \cdot \left({\left(x-scale \cdot y-scale\right)}^{-2} \cdot -4\right) \]
  9. Simplified83.0%

    \[\leadsto \color{blue}{{\left(a \cdot b\right)}^{2} \cdot \left({\left(x-scale \cdot y-scale\right)}^{-2} \cdot -4\right)} \]
  10. Step-by-step derivation
    1. unpow283.0%

      \[\leadsto \color{blue}{\left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right)} \cdot \left({\left(x-scale \cdot y-scale\right)}^{-2} \cdot -4\right) \]
  11. Applied egg-rr83.0%

    \[\leadsto \color{blue}{\left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right)} \cdot \left({\left(x-scale \cdot y-scale\right)}^{-2} \cdot -4\right) \]
  12. Step-by-step derivation
    1. sqr-pow82.9%

      \[\leadsto \left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \left(\color{blue}{\left({\left(x-scale \cdot y-scale\right)}^{\left(\frac{-2}{2}\right)} \cdot {\left(x-scale \cdot y-scale\right)}^{\left(\frac{-2}{2}\right)}\right)} \cdot -4\right) \]
    2. metadata-eval82.9%

      \[\leadsto \left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \left(\left({\left(x-scale \cdot y-scale\right)}^{\color{blue}{-1}} \cdot {\left(x-scale \cdot y-scale\right)}^{\left(\frac{-2}{2}\right)}\right) \cdot -4\right) \]
    3. unpow-182.9%

      \[\leadsto \left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \left(\left(\color{blue}{\frac{1}{x-scale \cdot y-scale}} \cdot {\left(x-scale \cdot y-scale\right)}^{\left(\frac{-2}{2}\right)}\right) \cdot -4\right) \]
    4. metadata-eval82.9%

      \[\leadsto \left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \left(\left(\frac{1}{x-scale \cdot y-scale} \cdot {\left(x-scale \cdot y-scale\right)}^{\color{blue}{-1}}\right) \cdot -4\right) \]
    5. unpow-182.9%

      \[\leadsto \left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \left(\left(\frac{1}{x-scale \cdot y-scale} \cdot \color{blue}{\frac{1}{x-scale \cdot y-scale}}\right) \cdot -4\right) \]
  13. Applied egg-rr82.9%

    \[\leadsto \left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \left(\color{blue}{\left(\frac{1}{x-scale \cdot y-scale} \cdot \frac{1}{x-scale \cdot y-scale}\right)} \cdot -4\right) \]
  14. Final simplification82.9%

    \[\leadsto \left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \left(-4 \cdot \left(\frac{1}{x-scale \cdot y-scale} \cdot \frac{1}{x-scale \cdot y-scale}\right)\right) \]

Alternative 3: 77.4% accurate, 146.2× speedup?

\[\begin{array}{l} \\ \left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \frac{-4}{\left(x-scale \cdot y-scale\right) \cdot \left(x-scale \cdot y-scale\right)} \end{array} \]
(FPCore (a b angle x-scale y-scale)
 :precision binary64
 (* (* (* a b) (* a b)) (/ -4.0 (* (* x-scale y-scale) (* x-scale y-scale)))))
double code(double a, double b, double angle, double x_45_scale, double y_45_scale) {
	return ((a * b) * (a * b)) * (-4.0 / ((x_45_scale * y_45_scale) * (x_45_scale * y_45_scale)));
}
real(8) function code(a, b, angle, x_45scale, y_45scale)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: angle
    real(8), intent (in) :: x_45scale
    real(8), intent (in) :: y_45scale
    code = ((a * b) * (a * b)) * ((-4.0d0) / ((x_45scale * y_45scale) * (x_45scale * y_45scale)))
end function
public static double code(double a, double b, double angle, double x_45_scale, double y_45_scale) {
	return ((a * b) * (a * b)) * (-4.0 / ((x_45_scale * y_45_scale) * (x_45_scale * y_45_scale)));
}
def code(a, b, angle, x_45_scale, y_45_scale):
	return ((a * b) * (a * b)) * (-4.0 / ((x_45_scale * y_45_scale) * (x_45_scale * y_45_scale)))
function code(a, b, angle, x_45_scale, y_45_scale)
	return Float64(Float64(Float64(a * b) * Float64(a * b)) * Float64(-4.0 / Float64(Float64(x_45_scale * y_45_scale) * Float64(x_45_scale * y_45_scale))))
end
function tmp = code(a, b, angle, x_45_scale, y_45_scale)
	tmp = ((a * b) * (a * b)) * (-4.0 / ((x_45_scale * y_45_scale) * (x_45_scale * y_45_scale)));
end
code[a_, b_, angle_, x$45$scale_, y$45$scale_] := N[(N[(N[(a * b), $MachinePrecision] * N[(a * b), $MachinePrecision]), $MachinePrecision] * N[(-4.0 / N[(N[(x$45$scale * y$45$scale), $MachinePrecision] * N[(x$45$scale * y$45$scale), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \frac{-4}{\left(x-scale \cdot y-scale\right) \cdot \left(x-scale \cdot y-scale\right)}
\end{array}
Derivation
  1. Initial program 22.6%

    \[\frac{\frac{\left(\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)}{x-scale}}{y-scale} \cdot \frac{\frac{\left(\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)}{x-scale}}{y-scale} - \left(4 \cdot \frac{\frac{{\left(a \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{x-scale}}{x-scale}\right) \cdot \frac{\frac{{\left(a \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{y-scale}}{y-scale} \]
  2. Simplified20.5%

    \[\leadsto \color{blue}{\frac{\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \left(\sin \left(\frac{angle}{180} \cdot \pi\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}{y-scale \cdot x-scale} \cdot \frac{\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \left(\sin \left(\frac{angle}{180} \cdot \pi\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}{y-scale \cdot x-scale} - 4 \cdot \left(\frac{{\left(a \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{{x-scale}^{2}} \cdot \frac{{\left(a \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{{y-scale}^{2}}\right)} \]
  3. Taylor expanded in angle around 0 53.5%

    \[\leadsto \color{blue}{-4 \cdot \frac{{a}^{2} \cdot {b}^{2}}{{x-scale}^{2} \cdot {y-scale}^{2}}} \]
  4. Step-by-step derivation
    1. associate-*r/53.5%

      \[\leadsto \color{blue}{\frac{-4 \cdot \left({a}^{2} \cdot {b}^{2}\right)}{{x-scale}^{2} \cdot {y-scale}^{2}}} \]
    2. *-commutative53.5%

      \[\leadsto \frac{-4 \cdot \color{blue}{\left({b}^{2} \cdot {a}^{2}\right)}}{{x-scale}^{2} \cdot {y-scale}^{2}} \]
    3. unpow253.5%

      \[\leadsto \frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{\color{blue}{\left(x-scale \cdot x-scale\right)} \cdot {y-scale}^{2}} \]
    4. unpow253.5%

      \[\leadsto \frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{\left(x-scale \cdot x-scale\right) \cdot \color{blue}{\left(y-scale \cdot y-scale\right)}} \]
    5. swap-sqr66.4%

      \[\leadsto \frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{\color{blue}{\left(x-scale \cdot y-scale\right) \cdot \left(x-scale \cdot y-scale\right)}} \]
    6. unpow266.4%

      \[\leadsto \frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{\color{blue}{{\left(x-scale \cdot y-scale\right)}^{2}}} \]
  5. Simplified66.4%

    \[\leadsto \color{blue}{\frac{-4 \cdot \left({b}^{2} \cdot {a}^{2}\right)}{{\left(x-scale \cdot y-scale\right)}^{2}}} \]
  6. Taylor expanded in b around 0 53.5%

    \[\leadsto \color{blue}{-4 \cdot \frac{{a}^{2} \cdot {b}^{2}}{{x-scale}^{2} \cdot {y-scale}^{2}}} \]
  7. Step-by-step derivation
    1. associate-*r/53.5%

      \[\leadsto \color{blue}{\frac{-4 \cdot \left({a}^{2} \cdot {b}^{2}\right)}{{x-scale}^{2} \cdot {y-scale}^{2}}} \]
    2. *-commutative53.5%

      \[\leadsto \frac{-4 \cdot \color{blue}{\left({b}^{2} \cdot {a}^{2}\right)}}{{x-scale}^{2} \cdot {y-scale}^{2}} \]
    3. unpow253.5%

      \[\leadsto \frac{-4 \cdot \left(\color{blue}{\left(b \cdot b\right)} \cdot {a}^{2}\right)}{{x-scale}^{2} \cdot {y-scale}^{2}} \]
    4. unpow253.5%

      \[\leadsto \frac{-4 \cdot \left(\left(b \cdot b\right) \cdot \color{blue}{\left(a \cdot a\right)}\right)}{{x-scale}^{2} \cdot {y-scale}^{2}} \]
    5. swap-sqr66.3%

      \[\leadsto \frac{-4 \cdot \color{blue}{\left(\left(b \cdot a\right) \cdot \left(b \cdot a\right)\right)}}{{x-scale}^{2} \cdot {y-scale}^{2}} \]
    6. unpow266.3%

      \[\leadsto \frac{-4 \cdot \color{blue}{{\left(b \cdot a\right)}^{2}}}{{x-scale}^{2} \cdot {y-scale}^{2}} \]
    7. associate-/l*66.3%

      \[\leadsto \color{blue}{\frac{-4}{\frac{{x-scale}^{2} \cdot {y-scale}^{2}}{{\left(b \cdot a\right)}^{2}}}} \]
    8. associate-/r/66.4%

      \[\leadsto \color{blue}{\frac{-4}{{x-scale}^{2} \cdot {y-scale}^{2}} \cdot {\left(b \cdot a\right)}^{2}} \]
    9. unpow266.4%

      \[\leadsto \frac{-4}{\color{blue}{\left(x-scale \cdot x-scale\right)} \cdot {y-scale}^{2}} \cdot {\left(b \cdot a\right)}^{2} \]
    10. unpow266.4%

      \[\leadsto \frac{-4}{\left(x-scale \cdot x-scale\right) \cdot \color{blue}{\left(y-scale \cdot y-scale\right)}} \cdot {\left(b \cdot a\right)}^{2} \]
    11. swap-sqr82.6%

      \[\leadsto \frac{-4}{\color{blue}{\left(x-scale \cdot y-scale\right) \cdot \left(x-scale \cdot y-scale\right)}} \cdot {\left(b \cdot a\right)}^{2} \]
    12. unpow282.6%

      \[\leadsto \frac{-4}{\color{blue}{{\left(x-scale \cdot y-scale\right)}^{2}}} \cdot {\left(b \cdot a\right)}^{2} \]
    13. *-commutative82.6%

      \[\leadsto \frac{-4}{{\left(x-scale \cdot y-scale\right)}^{2}} \cdot {\color{blue}{\left(a \cdot b\right)}}^{2} \]
  8. Simplified82.6%

    \[\leadsto \color{blue}{\frac{-4}{{\left(x-scale \cdot y-scale\right)}^{2}} \cdot {\left(a \cdot b\right)}^{2}} \]
  9. Step-by-step derivation
    1. unpow283.0%

      \[\leadsto \color{blue}{\left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right)} \cdot \left({\left(x-scale \cdot y-scale\right)}^{-2} \cdot -4\right) \]
  10. Applied egg-rr82.6%

    \[\leadsto \frac{-4}{{\left(x-scale \cdot y-scale\right)}^{2}} \cdot \color{blue}{\left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right)} \]
  11. Step-by-step derivation
    1. unpow282.6%

      \[\leadsto \frac{-4}{\color{blue}{\left(x-scale \cdot y-scale\right) \cdot \left(x-scale \cdot y-scale\right)}} \cdot \left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \]
  12. Applied egg-rr82.6%

    \[\leadsto \frac{-4}{\color{blue}{\left(x-scale \cdot y-scale\right) \cdot \left(x-scale \cdot y-scale\right)}} \cdot \left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \]
  13. Final simplification82.6%

    \[\leadsto \left(\left(a \cdot b\right) \cdot \left(a \cdot b\right)\right) \cdot \frac{-4}{\left(x-scale \cdot y-scale\right) \cdot \left(x-scale \cdot y-scale\right)} \]

Alternative 4: 35.1% accurate, 2485.0× speedup?

\[\begin{array}{l} \\ 0 \end{array} \]
(FPCore (a b angle x-scale y-scale) :precision binary64 0.0)
double code(double a, double b, double angle, double x_45_scale, double y_45_scale) {
	return 0.0;
}
real(8) function code(a, b, angle, x_45scale, y_45scale)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: angle
    real(8), intent (in) :: x_45scale
    real(8), intent (in) :: y_45scale
    code = 0.0d0
end function
public static double code(double a, double b, double angle, double x_45_scale, double y_45_scale) {
	return 0.0;
}
def code(a, b, angle, x_45_scale, y_45_scale):
	return 0.0
function code(a, b, angle, x_45_scale, y_45_scale)
	return 0.0
end
function tmp = code(a, b, angle, x_45_scale, y_45_scale)
	tmp = 0.0;
end
code[a_, b_, angle_, x$45$scale_, y$45$scale_] := 0.0
\begin{array}{l}

\\
0
\end{array}
Derivation
  1. Initial program 22.6%

    \[\frac{\frac{\left(\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)}{x-scale}}{y-scale} \cdot \frac{\frac{\left(\left(2 \cdot \left({b}^{2} - {a}^{2}\right)\right) \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)}{x-scale}}{y-scale} - \left(4 \cdot \frac{\frac{{\left(a \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{x-scale}}{x-scale}\right) \cdot \frac{\frac{{\left(a \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{y-scale}}{y-scale} \]
  2. Simplified21.4%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{2 \cdot \left({b}^{2} - {a}^{2}\right)}{x-scale \cdot y-scale} \cdot \left(\sin \left(\frac{angle}{180} \cdot \pi\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right), \frac{2 \cdot \left({b}^{2} - {a}^{2}\right)}{x-scale \cdot y-scale} \cdot \left(\sin \left(\frac{angle}{180} \cdot \pi\right) \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right), \frac{{\left(a \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{{y-scale}^{2}} \cdot \left(\frac{{\left(a \cdot \sin \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2} + {\left(b \cdot \cos \left(\frac{angle}{180} \cdot \pi\right)\right)}^{2}}{{x-scale}^{2}} \cdot -4\right)\right)} \]
  3. Taylor expanded in b around 0 22.7%

    \[\leadsto \color{blue}{-4 \cdot \frac{{a}^{4} \cdot \left({\cos \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{2} \cdot {\sin \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{2}\right)}{{x-scale}^{2} \cdot {y-scale}^{2}} + 4 \cdot \frac{{a}^{4} \cdot \left({\cos \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{2} \cdot {\sin \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{2}\right)}{{x-scale}^{2} \cdot {y-scale}^{2}}} \]
  4. Step-by-step derivation
    1. distribute-rgt-out22.7%

      \[\leadsto \color{blue}{\frac{{a}^{4} \cdot \left({\cos \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{2} \cdot {\sin \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{2}\right)}{{x-scale}^{2} \cdot {y-scale}^{2}} \cdot \left(-4 + 4\right)} \]
    2. metadata-eval22.7%

      \[\leadsto \frac{{a}^{4} \cdot \left({\cos \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{2} \cdot {\sin \left(0.005555555555555556 \cdot \left(angle \cdot \pi\right)\right)}^{2}\right)}{{x-scale}^{2} \cdot {y-scale}^{2}} \cdot \color{blue}{0} \]
    3. mul0-rgt30.3%

      \[\leadsto \color{blue}{0} \]
  5. Simplified30.3%

    \[\leadsto \color{blue}{0} \]
  6. Final simplification30.3%

    \[\leadsto 0 \]

Reproduce

?
herbie shell --seed 2023318 
(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))))