
(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:
Herbie found 3 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(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}
x-scale_m = (fabs.f64 x-scale) y-scale_m = (fabs.f64 y-scale) (FPCore (a b angle x-scale_m y-scale_m) :precision binary64 (let* ((t_0 (/ (* b a) (sqrt (* x-scale_m y-scale_m))))) (* t_0 (* t_0 (/ (/ -4.0 x-scale_m) y-scale_m)))))
x-scale_m = fabs(x_45_scale);
y-scale_m = fabs(y_45_scale);
double code(double a, double b, double angle, double x_45_scale_m, double y_45_scale_m) {
double t_0 = (b * a) / sqrt((x_45_scale_m * y_45_scale_m));
return t_0 * (t_0 * ((-4.0 / x_45_scale_m) / y_45_scale_m));
}
x-scale_m = abs(x_45scale)
y-scale_m = abs(y_45scale)
real(8) function code(a, b, angle, x_45scale_m, y_45scale_m)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: angle
real(8), intent (in) :: x_45scale_m
real(8), intent (in) :: y_45scale_m
real(8) :: t_0
t_0 = (b * a) / sqrt((x_45scale_m * y_45scale_m))
code = t_0 * (t_0 * (((-4.0d0) / x_45scale_m) / y_45scale_m))
end function
x-scale_m = Math.abs(x_45_scale);
y-scale_m = Math.abs(y_45_scale);
public static double code(double a, double b, double angle, double x_45_scale_m, double y_45_scale_m) {
double t_0 = (b * a) / Math.sqrt((x_45_scale_m * y_45_scale_m));
return t_0 * (t_0 * ((-4.0 / x_45_scale_m) / y_45_scale_m));
}
x-scale_m = math.fabs(x_45_scale) y-scale_m = math.fabs(y_45_scale) def code(a, b, angle, x_45_scale_m, y_45_scale_m): t_0 = (b * a) / math.sqrt((x_45_scale_m * y_45_scale_m)) return t_0 * (t_0 * ((-4.0 / x_45_scale_m) / y_45_scale_m))
x-scale_m = abs(x_45_scale) y-scale_m = abs(y_45_scale) function code(a, b, angle, x_45_scale_m, y_45_scale_m) t_0 = Float64(Float64(b * a) / sqrt(Float64(x_45_scale_m * y_45_scale_m))) return Float64(t_0 * Float64(t_0 * Float64(Float64(-4.0 / x_45_scale_m) / y_45_scale_m))) end
x-scale_m = abs(x_45_scale); y-scale_m = abs(y_45_scale); function tmp = code(a, b, angle, x_45_scale_m, y_45_scale_m) t_0 = (b * a) / sqrt((x_45_scale_m * y_45_scale_m)); tmp = t_0 * (t_0 * ((-4.0 / x_45_scale_m) / y_45_scale_m)); end
x-scale_m = N[Abs[x$45$scale], $MachinePrecision]
y-scale_m = N[Abs[y$45$scale], $MachinePrecision]
code[a_, b_, angle_, x$45$scale$95$m_, y$45$scale$95$m_] := Block[{t$95$0 = N[(N[(b * a), $MachinePrecision] / N[Sqrt[N[(x$45$scale$95$m * y$45$scale$95$m), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, N[(t$95$0 * N[(t$95$0 * N[(N[(-4.0 / x$45$scale$95$m), $MachinePrecision] / y$45$scale$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
x-scale_m = \left|x-scale\right|
\\
y-scale_m = \left|y-scale\right|
\\
\begin{array}{l}
t_0 := \frac{b \cdot a}{\sqrt{x-scale\_m \cdot y-scale\_m}}\\
t\_0 \cdot \left(t\_0 \cdot \frac{\frac{-4}{x-scale\_m}}{y-scale\_m}\right)
\end{array}
\end{array}
Initial program 29.6%
Simplified27.3%
Taylor expanded in angle around 0 51.3%
associate-*r/51.3%
*-commutative51.3%
*-commutative51.3%
unpow251.3%
unpow251.3%
swap-sqr60.9%
unpow260.9%
*-commutative60.9%
Simplified60.9%
pow-prod-down77.6%
Applied egg-rr77.6%
unpow277.6%
*-commutative77.6%
associate-*r*74.8%
Applied egg-rr74.8%
*-commutative74.8%
associate-*l*77.6%
*-commutative77.6%
unpow277.6%
unpow277.6%
frac-times82.3%
add-sqr-sqrt57.8%
associate-*l*57.8%
sqrt-div40.9%
sqrt-pow128.1%
metadata-eval28.1%
pow128.1%
sqrt-div30.5%
sqrt-pow146.1%
metadata-eval46.1%
pow146.1%
associate-/r*46.1%
Applied egg-rr46.1%
Final simplification46.1%
x-scale_m = (fabs.f64 x-scale) y-scale_m = (fabs.f64 y-scale) (FPCore (a b angle x-scale_m y-scale_m) :precision binary64 (* (* (* b a) (/ (* b a) (* x-scale_m y-scale_m))) (/ -4.0 (* x-scale_m y-scale_m))))
x-scale_m = fabs(x_45_scale);
y-scale_m = fabs(y_45_scale);
double code(double a, double b, double angle, double x_45_scale_m, double y_45_scale_m) {
return ((b * a) * ((b * a) / (x_45_scale_m * y_45_scale_m))) * (-4.0 / (x_45_scale_m * y_45_scale_m));
}
x-scale_m = abs(x_45scale)
y-scale_m = abs(y_45scale)
real(8) function code(a, b, angle, x_45scale_m, y_45scale_m)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: angle
real(8), intent (in) :: x_45scale_m
real(8), intent (in) :: y_45scale_m
code = ((b * a) * ((b * a) / (x_45scale_m * y_45scale_m))) * ((-4.0d0) / (x_45scale_m * y_45scale_m))
end function
x-scale_m = Math.abs(x_45_scale);
y-scale_m = Math.abs(y_45_scale);
public static double code(double a, double b, double angle, double x_45_scale_m, double y_45_scale_m) {
return ((b * a) * ((b * a) / (x_45_scale_m * y_45_scale_m))) * (-4.0 / (x_45_scale_m * y_45_scale_m));
}
x-scale_m = math.fabs(x_45_scale) y-scale_m = math.fabs(y_45_scale) def code(a, b, angle, x_45_scale_m, y_45_scale_m): return ((b * a) * ((b * a) / (x_45_scale_m * y_45_scale_m))) * (-4.0 / (x_45_scale_m * y_45_scale_m))
x-scale_m = abs(x_45_scale) y-scale_m = abs(y_45_scale) function code(a, b, angle, x_45_scale_m, y_45_scale_m) return Float64(Float64(Float64(b * a) * Float64(Float64(b * a) / Float64(x_45_scale_m * y_45_scale_m))) * Float64(-4.0 / Float64(x_45_scale_m * y_45_scale_m))) end
x-scale_m = abs(x_45_scale); y-scale_m = abs(y_45_scale); function tmp = code(a, b, angle, x_45_scale_m, y_45_scale_m) tmp = ((b * a) * ((b * a) / (x_45_scale_m * y_45_scale_m))) * (-4.0 / (x_45_scale_m * y_45_scale_m)); end
x-scale_m = N[Abs[x$45$scale], $MachinePrecision] y-scale_m = N[Abs[y$45$scale], $MachinePrecision] code[a_, b_, angle_, x$45$scale$95$m_, y$45$scale$95$m_] := N[(N[(N[(b * a), $MachinePrecision] * N[(N[(b * a), $MachinePrecision] / N[(x$45$scale$95$m * y$45$scale$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(-4.0 / N[(x$45$scale$95$m * y$45$scale$95$m), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x-scale_m = \left|x-scale\right|
\\
y-scale_m = \left|y-scale\right|
\\
\left(\left(b \cdot a\right) \cdot \frac{b \cdot a}{x-scale\_m \cdot y-scale\_m}\right) \cdot \frac{-4}{x-scale\_m \cdot y-scale\_m}
\end{array}
Initial program 29.6%
Simplified27.3%
Taylor expanded in angle around 0 51.3%
associate-*r/51.3%
*-commutative51.3%
*-commutative51.3%
unpow251.3%
unpow251.3%
swap-sqr60.9%
unpow260.9%
*-commutative60.9%
Simplified60.9%
pow-prod-down77.6%
Applied egg-rr77.6%
*-commutative77.6%
unpow277.6%
times-frac82.3%
Applied egg-rr82.3%
unpow282.3%
associate-/l*88.7%
Applied egg-rr88.7%
Final simplification88.7%
x-scale_m = (fabs.f64 x-scale) y-scale_m = (fabs.f64 y-scale) (FPCore (a b angle x-scale_m y-scale_m) :precision binary64 0.0)
x-scale_m = fabs(x_45_scale);
y-scale_m = fabs(y_45_scale);
double code(double a, double b, double angle, double x_45_scale_m, double y_45_scale_m) {
return 0.0;
}
x-scale_m = abs(x_45scale)
y-scale_m = abs(y_45scale)
real(8) function code(a, b, angle, x_45scale_m, y_45scale_m)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: angle
real(8), intent (in) :: x_45scale_m
real(8), intent (in) :: y_45scale_m
code = 0.0d0
end function
x-scale_m = Math.abs(x_45_scale);
y-scale_m = Math.abs(y_45_scale);
public static double code(double a, double b, double angle, double x_45_scale_m, double y_45_scale_m) {
return 0.0;
}
x-scale_m = math.fabs(x_45_scale) y-scale_m = math.fabs(y_45_scale) def code(a, b, angle, x_45_scale_m, y_45_scale_m): return 0.0
x-scale_m = abs(x_45_scale) y-scale_m = abs(y_45_scale) function code(a, b, angle, x_45_scale_m, y_45_scale_m) return 0.0 end
x-scale_m = abs(x_45_scale); y-scale_m = abs(y_45_scale); function tmp = code(a, b, angle, x_45_scale_m, y_45_scale_m) tmp = 0.0; end
x-scale_m = N[Abs[x$45$scale], $MachinePrecision] y-scale_m = N[Abs[y$45$scale], $MachinePrecision] code[a_, b_, angle_, x$45$scale$95$m_, y$45$scale$95$m_] := 0.0
\begin{array}{l}
x-scale_m = \left|x-scale\right|
\\
y-scale_m = \left|y-scale\right|
\\
0
\end{array}
Initial program 29.6%
Simplified27.8%
Taylor expanded in b around 0 30.5%
distribute-rgt-out30.5%
metadata-eval30.5%
mul0-rgt40.4%
Simplified40.4%
Final simplification40.4%
herbie shell --seed 2024055
(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))))