Eccentricity of an ellipse

Percentage Accurate: 77.6% → 100.0%
Time: 6.0s
Alternatives: 5
Speedup: 211.0×

Specification

?
\[\left(0 \leq b \land b \leq a\right) \land a \leq 1\]
\[\begin{array}{l} \\ \sqrt{\left|\frac{a \cdot a - b \cdot b}{a \cdot a}\right|} \end{array} \]
(FPCore (a b)
 :precision binary64
 (sqrt (fabs (/ (- (* a a) (* b b)) (* a a)))))
double code(double a, double b) {
	return sqrt(fabs((((a * a) - (b * b)) / (a * a))));
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = sqrt(abs((((a * a) - (b * b)) / (a * a))))
end function
public static double code(double a, double b) {
	return Math.sqrt(Math.abs((((a * a) - (b * b)) / (a * a))));
}
def code(a, b):
	return math.sqrt(math.fabs((((a * a) - (b * b)) / (a * a))))
function code(a, b)
	return sqrt(abs(Float64(Float64(Float64(a * a) - Float64(b * b)) / Float64(a * a))))
end
function tmp = code(a, b)
	tmp = sqrt(abs((((a * a) - (b * b)) / (a * a))));
end
code[a_, b_] := N[Sqrt[N[Abs[N[(N[(N[(a * a), $MachinePrecision] - N[(b * b), $MachinePrecision]), $MachinePrecision] / N[(a * a), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{\left|\frac{a \cdot a - b \cdot b}{a \cdot a}\right|}
\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 5 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: 77.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \sqrt{\left|\frac{a \cdot a - b \cdot b}{a \cdot a}\right|} \end{array} \]
(FPCore (a b)
 :precision binary64
 (sqrt (fabs (/ (- (* a a) (* b b)) (* a a)))))
double code(double a, double b) {
	return sqrt(fabs((((a * a) - (b * b)) / (a * a))));
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = sqrt(abs((((a * a) - (b * b)) / (a * a))))
end function
public static double code(double a, double b) {
	return Math.sqrt(Math.abs((((a * a) - (b * b)) / (a * a))));
}
def code(a, b):
	return math.sqrt(math.fabs((((a * a) - (b * b)) / (a * a))))
function code(a, b)
	return sqrt(abs(Float64(Float64(Float64(a * a) - Float64(b * b)) / Float64(a * a))))
end
function tmp = code(a, b)
	tmp = sqrt(abs((((a * a) - (b * b)) / (a * a))));
end
code[a_, b_] := N[Sqrt[N[Abs[N[(N[(N[(a * a), $MachinePrecision] - N[(b * b), $MachinePrecision]), $MachinePrecision] / N[(a * a), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{\left|\frac{a \cdot a - b \cdot b}{a \cdot a}\right|}
\end{array}

Alternative 1: 100.0% accurate, 0.7× speedup?

\[\begin{array}{l} \\ e^{\mathsf{log1p}\left(-{\left(\frac{b}{a}\right)}^{2}\right) \cdot 0.5} \end{array} \]
(FPCore (a b) :precision binary64 (exp (* (log1p (- (pow (/ b a) 2.0))) 0.5)))
double code(double a, double b) {
	return exp((log1p(-pow((b / a), 2.0)) * 0.5));
}
public static double code(double a, double b) {
	return Math.exp((Math.log1p(-Math.pow((b / a), 2.0)) * 0.5));
}
def code(a, b):
	return math.exp((math.log1p(-math.pow((b / a), 2.0)) * 0.5))
function code(a, b)
	return exp(Float64(log1p(Float64(-(Float64(b / a) ^ 2.0))) * 0.5))
end
code[a_, b_] := N[Exp[N[(N[Log[1 + (-N[Power[N[(b / a), $MachinePrecision], 2.0], $MachinePrecision])], $MachinePrecision] * 0.5), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
e^{\mathsf{log1p}\left(-{\left(\frac{b}{a}\right)}^{2}\right) \cdot 0.5}
\end{array}
Derivation
  1. Initial program 79.3%

    \[\sqrt{\left|\frac{a \cdot a - b \cdot b}{a \cdot a}\right|} \]
  2. Step-by-step derivation
    1. sqr-neg79.3%

      \[\leadsto \sqrt{\left|\frac{a \cdot a - \color{blue}{\left(-b\right) \cdot \left(-b\right)}}{a \cdot a}\right|} \]
    2. fabs-div79.3%

      \[\leadsto \sqrt{\color{blue}{\frac{\left|a \cdot a - \left(-b\right) \cdot \left(-b\right)\right|}{\left|a \cdot a\right|}}} \]
    3. sqr-neg79.3%

      \[\leadsto \sqrt{\frac{\left|a \cdot a - \color{blue}{b \cdot b}\right|}{\left|a \cdot a\right|}} \]
    4. fabs-sub79.3%

      \[\leadsto \sqrt{\frac{\color{blue}{\left|b \cdot b - a \cdot a\right|}}{\left|a \cdot a\right|}} \]
    5. sqr-neg79.3%

      \[\leadsto \sqrt{\frac{\left|b \cdot b - a \cdot a\right|}{\left|\color{blue}{\left(-a\right) \cdot \left(-a\right)}\right|}} \]
    6. distribute-rgt-neg-out79.3%

      \[\leadsto \sqrt{\frac{\left|b \cdot b - a \cdot a\right|}{\left|\color{blue}{-\left(-a\right) \cdot a}\right|}} \]
    7. fabs-neg79.3%

      \[\leadsto \sqrt{\frac{\left|b \cdot b - a \cdot a\right|}{\color{blue}{\left|\left(-a\right) \cdot a\right|}}} \]
    8. fabs-div79.3%

      \[\leadsto \sqrt{\color{blue}{\left|\frac{b \cdot b - a \cdot a}{\left(-a\right) \cdot a}\right|}} \]
    9. cancel-sign-sub-inv79.3%

      \[\leadsto \sqrt{\left|\frac{\color{blue}{b \cdot b + \left(-a\right) \cdot a}}{\left(-a\right) \cdot a}\right|} \]
    10. +-commutative79.3%

      \[\leadsto \sqrt{\left|\frac{\color{blue}{\left(-a\right) \cdot a + b \cdot b}}{\left(-a\right) \cdot a}\right|} \]
    11. sqr-neg79.3%

      \[\leadsto \sqrt{\left|\frac{\left(-a\right) \cdot a + \color{blue}{\left(-b\right) \cdot \left(-b\right)}}{\left(-a\right) \cdot a}\right|} \]
    12. cancel-sign-sub-inv79.3%

      \[\leadsto \sqrt{\left|\frac{\color{blue}{\left(-a\right) \cdot a - b \cdot \left(-b\right)}}{\left(-a\right) \cdot a}\right|} \]
    13. div-sub79.3%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{\left(-a\right) \cdot a}{\left(-a\right) \cdot a} - \frac{b \cdot \left(-b\right)}{\left(-a\right) \cdot a}}\right|} \]
  3. Simplified79.9%

    \[\leadsto \color{blue}{\sqrt{\left|1 - b \cdot \frac{b}{a \cdot a}\right|}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. pow1/279.9%

      \[\leadsto \color{blue}{{\left(\left|1 - b \cdot \frac{b}{a \cdot a}\right|\right)}^{0.5}} \]
    2. pow-to-exp79.9%

      \[\leadsto \color{blue}{e^{\log \left(\left|1 - b \cdot \frac{b}{a \cdot a}\right|\right) \cdot 0.5}} \]
    3. add-sqr-sqrt79.3%

      \[\leadsto e^{\log \left(\left|\color{blue}{\sqrt{1 - b \cdot \frac{b}{a \cdot a}} \cdot \sqrt{1 - b \cdot \frac{b}{a \cdot a}}}\right|\right) \cdot 0.5} \]
    4. fabs-sqr79.3%

      \[\leadsto e^{\log \color{blue}{\left(\sqrt{1 - b \cdot \frac{b}{a \cdot a}} \cdot \sqrt{1 - b \cdot \frac{b}{a \cdot a}}\right)} \cdot 0.5} \]
    5. add-sqr-sqrt79.3%

      \[\leadsto e^{\log \color{blue}{\left(1 - b \cdot \frac{b}{a \cdot a}\right)} \cdot 0.5} \]
    6. sub-neg79.3%

      \[\leadsto e^{\log \color{blue}{\left(1 + \left(-b \cdot \frac{b}{a \cdot a}\right)\right)} \cdot 0.5} \]
    7. log1p-define79.3%

      \[\leadsto e^{\color{blue}{\mathsf{log1p}\left(-b \cdot \frac{b}{a \cdot a}\right)} \cdot 0.5} \]
    8. associate-*r/79.3%

      \[\leadsto e^{\mathsf{log1p}\left(-\color{blue}{\frac{b \cdot b}{a \cdot a}}\right) \cdot 0.5} \]
    9. frac-times100.0%

      \[\leadsto e^{\mathsf{log1p}\left(-\color{blue}{\frac{b}{a} \cdot \frac{b}{a}}\right) \cdot 0.5} \]
    10. pow2100.0%

      \[\leadsto e^{\mathsf{log1p}\left(-\color{blue}{{\left(\frac{b}{a}\right)}^{2}}\right) \cdot 0.5} \]
  6. Applied egg-rr100.0%

    \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(-{\left(\frac{b}{a}\right)}^{2}\right) \cdot 0.5}} \]
  7. Add Preprocessing

Alternative 2: 100.0% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \sqrt{\frac{a - b}{a \cdot \frac{a}{b + a}}} \end{array} \]
(FPCore (a b) :precision binary64 (sqrt (/ (- a b) (* a (/ a (+ b a))))))
double code(double a, double b) {
	return sqrt(((a - b) / (a * (a / (b + a)))));
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = sqrt(((a - b) / (a * (a / (b + a)))))
end function
public static double code(double a, double b) {
	return Math.sqrt(((a - b) / (a * (a / (b + a)))));
}
def code(a, b):
	return math.sqrt(((a - b) / (a * (a / (b + a)))))
function code(a, b)
	return sqrt(Float64(Float64(a - b) / Float64(a * Float64(a / Float64(b + a)))))
end
function tmp = code(a, b)
	tmp = sqrt(((a - b) / (a * (a / (b + a)))));
end
code[a_, b_] := N[Sqrt[N[(N[(a - b), $MachinePrecision] / N[(a * N[(a / N[(b + a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{\frac{a - b}{a \cdot \frac{a}{b + a}}}
\end{array}
Derivation
  1. Initial program 79.3%

    \[\sqrt{\left|\frac{a \cdot a - b \cdot b}{a \cdot a}\right|} \]
  2. Step-by-step derivation
    1. sqr-neg79.3%

      \[\leadsto \sqrt{\left|\frac{a \cdot a - \color{blue}{\left(-b\right) \cdot \left(-b\right)}}{a \cdot a}\right|} \]
    2. associate-/r*78.7%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{\frac{a \cdot a - \left(-b\right) \cdot \left(-b\right)}{a}}{a}}\right|} \]
    3. sqr-neg78.7%

      \[\leadsto \sqrt{\left|\frac{\frac{a \cdot a - \color{blue}{b \cdot b}}{a}}{a}\right|} \]
    4. associate-/r*79.3%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{a \cdot a - b \cdot b}{a \cdot a}}\right|} \]
    5. div-sub79.3%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{a \cdot a}{a \cdot a} - \frac{b \cdot b}{a \cdot a}}\right|} \]
    6. fabs-sub79.3%

      \[\leadsto \sqrt{\color{blue}{\left|\frac{b \cdot b}{a \cdot a} - \frac{a \cdot a}{a \cdot a}\right|}} \]
    7. times-frac79.3%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{b}{a} \cdot \frac{b}{a}} - \frac{a \cdot a}{a \cdot a}\right|} \]
    8. *-inverses100.0%

      \[\leadsto \sqrt{\left|\frac{b}{a} \cdot \frac{b}{a} - \color{blue}{1}\right|} \]
    9. difference-of-sqr-199.9%

      \[\leadsto \sqrt{\left|\color{blue}{\left(\frac{b}{a} + 1\right) \cdot \left(\frac{b}{a} - 1\right)}\right|} \]
    10. difference-of-sqr--1100.0%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{b}{a} \cdot \frac{b}{a} + -1}\right|} \]
    11. fma-define100.0%

      \[\leadsto \sqrt{\left|\color{blue}{\mathsf{fma}\left(\frac{b}{a}, \frac{b}{a}, -1\right)}\right|} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\sqrt{\left|\mathsf{fma}\left(\frac{b}{a}, \frac{b}{a}, -1\right)\right|}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. add-sqr-sqrt100.0%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\frac{\color{blue}{\sqrt{b} \cdot \sqrt{b}}}{a}, \frac{b}{a}, -1\right)\right|} \]
    2. associate-/l*100.0%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\color{blue}{\sqrt{b} \cdot \frac{\sqrt{b}}{a}}, \frac{b}{a}, -1\right)\right|} \]
    3. add-sqr-sqrt100.0%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b} \cdot \frac{\sqrt{b}}{\color{blue}{\sqrt{a} \cdot \sqrt{a}}}, \frac{b}{a}, -1\right)\right|} \]
    4. sqrt-prod79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b} \cdot \frac{\sqrt{b}}{\color{blue}{\sqrt{a \cdot a}}}, \frac{b}{a}, -1\right)\right|} \]
    5. sqrt-div79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b} \cdot \color{blue}{\sqrt{\frac{b}{a \cdot a}}}, \frac{b}{a}, -1\right)\right|} \]
    6. sqrt-prod79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\color{blue}{\sqrt{b \cdot \frac{b}{a \cdot a}}}, \frac{b}{a}, -1\right)\right|} \]
    7. add-sqr-sqrt79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \frac{\color{blue}{\sqrt{b} \cdot \sqrt{b}}}{a}, -1\right)\right|} \]
    8. associate-/l*79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \color{blue}{\sqrt{b} \cdot \frac{\sqrt{b}}{a}}, -1\right)\right|} \]
    9. add-sqr-sqrt79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \sqrt{b} \cdot \frac{\sqrt{b}}{\color{blue}{\sqrt{a} \cdot \sqrt{a}}}, -1\right)\right|} \]
    10. sqrt-prod79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \sqrt{b} \cdot \frac{\sqrt{b}}{\color{blue}{\sqrt{a \cdot a}}}, -1\right)\right|} \]
    11. sqrt-div79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \sqrt{b} \cdot \color{blue}{\sqrt{\frac{b}{a \cdot a}}}, -1\right)\right|} \]
    12. sqrt-prod79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \color{blue}{\sqrt{b \cdot \frac{b}{a \cdot a}}}, -1\right)\right|} \]
    13. metadata-eval79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \sqrt{b \cdot \frac{b}{a \cdot a}}, \color{blue}{-1}\right)\right|} \]
    14. fmm-def79.9%

      \[\leadsto \sqrt{\left|\color{blue}{\sqrt{b \cdot \frac{b}{a \cdot a}} \cdot \sqrt{b \cdot \frac{b}{a \cdot a}} - 1}\right|} \]
    15. add-sqr-sqrt79.9%

      \[\leadsto \sqrt{\left|\color{blue}{b \cdot \frac{b}{a \cdot a}} - 1\right|} \]
    16. fabs-sub79.9%

      \[\leadsto \sqrt{\color{blue}{\left|1 - b \cdot \frac{b}{a \cdot a}\right|}} \]
    17. *-inverses79.3%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{a \cdot a}{a \cdot a}} - b \cdot \frac{b}{a \cdot a}\right|} \]
    18. associate-*r/79.3%

      \[\leadsto \sqrt{\left|\frac{a \cdot a}{a \cdot a} - \color{blue}{\frac{b \cdot b}{a \cdot a}}\right|} \]
  6. Applied egg-rr99.9%

    \[\leadsto \sqrt{\color{blue}{\frac{b + a}{a} \cdot \frac{a - b}{a}}} \]
  7. Step-by-step derivation
    1. clear-num100.0%

      \[\leadsto \sqrt{\color{blue}{\frac{1}{\frac{a}{b + a}}} \cdot \frac{a - b}{a}} \]
    2. frac-times100.0%

      \[\leadsto \sqrt{\color{blue}{\frac{1 \cdot \left(a - b\right)}{\frac{a}{b + a} \cdot a}}} \]
    3. *-un-lft-identity100.0%

      \[\leadsto \sqrt{\frac{\color{blue}{a - b}}{\frac{a}{b + a} \cdot a}} \]
  8. Applied egg-rr100.0%

    \[\leadsto \sqrt{\color{blue}{\frac{a - b}{\frac{a}{b + a} \cdot a}}} \]
  9. Final simplification100.0%

    \[\leadsto \sqrt{\frac{a - b}{a \cdot \frac{a}{b + a}}} \]
  10. Add Preprocessing

Alternative 3: 100.0% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \sqrt{\frac{b + a}{a \cdot \frac{a}{a - b}}} \end{array} \]
(FPCore (a b) :precision binary64 (sqrt (/ (+ b a) (* a (/ a (- a b))))))
double code(double a, double b) {
	return sqrt(((b + a) / (a * (a / (a - b)))));
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = sqrt(((b + a) / (a * (a / (a - b)))))
end function
public static double code(double a, double b) {
	return Math.sqrt(((b + a) / (a * (a / (a - b)))));
}
def code(a, b):
	return math.sqrt(((b + a) / (a * (a / (a - b)))))
function code(a, b)
	return sqrt(Float64(Float64(b + a) / Float64(a * Float64(a / Float64(a - b)))))
end
function tmp = code(a, b)
	tmp = sqrt(((b + a) / (a * (a / (a - b)))));
end
code[a_, b_] := N[Sqrt[N[(N[(b + a), $MachinePrecision] / N[(a * N[(a / N[(a - b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{\frac{b + a}{a \cdot \frac{a}{a - b}}}
\end{array}
Derivation
  1. Initial program 79.3%

    \[\sqrt{\left|\frac{a \cdot a - b \cdot b}{a \cdot a}\right|} \]
  2. Step-by-step derivation
    1. sqr-neg79.3%

      \[\leadsto \sqrt{\left|\frac{a \cdot a - \color{blue}{\left(-b\right) \cdot \left(-b\right)}}{a \cdot a}\right|} \]
    2. associate-/r*78.7%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{\frac{a \cdot a - \left(-b\right) \cdot \left(-b\right)}{a}}{a}}\right|} \]
    3. sqr-neg78.7%

      \[\leadsto \sqrt{\left|\frac{\frac{a \cdot a - \color{blue}{b \cdot b}}{a}}{a}\right|} \]
    4. associate-/r*79.3%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{a \cdot a - b \cdot b}{a \cdot a}}\right|} \]
    5. div-sub79.3%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{a \cdot a}{a \cdot a} - \frac{b \cdot b}{a \cdot a}}\right|} \]
    6. fabs-sub79.3%

      \[\leadsto \sqrt{\color{blue}{\left|\frac{b \cdot b}{a \cdot a} - \frac{a \cdot a}{a \cdot a}\right|}} \]
    7. times-frac79.3%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{b}{a} \cdot \frac{b}{a}} - \frac{a \cdot a}{a \cdot a}\right|} \]
    8. *-inverses100.0%

      \[\leadsto \sqrt{\left|\frac{b}{a} \cdot \frac{b}{a} - \color{blue}{1}\right|} \]
    9. difference-of-sqr-199.9%

      \[\leadsto \sqrt{\left|\color{blue}{\left(\frac{b}{a} + 1\right) \cdot \left(\frac{b}{a} - 1\right)}\right|} \]
    10. difference-of-sqr--1100.0%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{b}{a} \cdot \frac{b}{a} + -1}\right|} \]
    11. fma-define100.0%

      \[\leadsto \sqrt{\left|\color{blue}{\mathsf{fma}\left(\frac{b}{a}, \frac{b}{a}, -1\right)}\right|} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\sqrt{\left|\mathsf{fma}\left(\frac{b}{a}, \frac{b}{a}, -1\right)\right|}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. add-sqr-sqrt100.0%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\frac{\color{blue}{\sqrt{b} \cdot \sqrt{b}}}{a}, \frac{b}{a}, -1\right)\right|} \]
    2. associate-/l*100.0%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\color{blue}{\sqrt{b} \cdot \frac{\sqrt{b}}{a}}, \frac{b}{a}, -1\right)\right|} \]
    3. add-sqr-sqrt100.0%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b} \cdot \frac{\sqrt{b}}{\color{blue}{\sqrt{a} \cdot \sqrt{a}}}, \frac{b}{a}, -1\right)\right|} \]
    4. sqrt-prod79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b} \cdot \frac{\sqrt{b}}{\color{blue}{\sqrt{a \cdot a}}}, \frac{b}{a}, -1\right)\right|} \]
    5. sqrt-div79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b} \cdot \color{blue}{\sqrt{\frac{b}{a \cdot a}}}, \frac{b}{a}, -1\right)\right|} \]
    6. sqrt-prod79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\color{blue}{\sqrt{b \cdot \frac{b}{a \cdot a}}}, \frac{b}{a}, -1\right)\right|} \]
    7. add-sqr-sqrt79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \frac{\color{blue}{\sqrt{b} \cdot \sqrt{b}}}{a}, -1\right)\right|} \]
    8. associate-/l*79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \color{blue}{\sqrt{b} \cdot \frac{\sqrt{b}}{a}}, -1\right)\right|} \]
    9. add-sqr-sqrt79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \sqrt{b} \cdot \frac{\sqrt{b}}{\color{blue}{\sqrt{a} \cdot \sqrt{a}}}, -1\right)\right|} \]
    10. sqrt-prod79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \sqrt{b} \cdot \frac{\sqrt{b}}{\color{blue}{\sqrt{a \cdot a}}}, -1\right)\right|} \]
    11. sqrt-div79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \sqrt{b} \cdot \color{blue}{\sqrt{\frac{b}{a \cdot a}}}, -1\right)\right|} \]
    12. sqrt-prod79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \color{blue}{\sqrt{b \cdot \frac{b}{a \cdot a}}}, -1\right)\right|} \]
    13. metadata-eval79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \sqrt{b \cdot \frac{b}{a \cdot a}}, \color{blue}{-1}\right)\right|} \]
    14. fmm-def79.9%

      \[\leadsto \sqrt{\left|\color{blue}{\sqrt{b \cdot \frac{b}{a \cdot a}} \cdot \sqrt{b \cdot \frac{b}{a \cdot a}} - 1}\right|} \]
    15. add-sqr-sqrt79.9%

      \[\leadsto \sqrt{\left|\color{blue}{b \cdot \frac{b}{a \cdot a}} - 1\right|} \]
    16. fabs-sub79.9%

      \[\leadsto \sqrt{\color{blue}{\left|1 - b \cdot \frac{b}{a \cdot a}\right|}} \]
    17. *-inverses79.3%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{a \cdot a}{a \cdot a}} - b \cdot \frac{b}{a \cdot a}\right|} \]
    18. associate-*r/79.3%

      \[\leadsto \sqrt{\left|\frac{a \cdot a}{a \cdot a} - \color{blue}{\frac{b \cdot b}{a \cdot a}}\right|} \]
  6. Applied egg-rr99.9%

    \[\leadsto \sqrt{\color{blue}{\frac{b + a}{a} \cdot \frac{a - b}{a}}} \]
  7. Step-by-step derivation
    1. *-commutative99.9%

      \[\leadsto \sqrt{\color{blue}{\frac{a - b}{a} \cdot \frac{b + a}{a}}} \]
    2. clear-num100.0%

      \[\leadsto \sqrt{\color{blue}{\frac{1}{\frac{a}{a - b}}} \cdot \frac{b + a}{a}} \]
    3. frac-times100.0%

      \[\leadsto \sqrt{\color{blue}{\frac{1 \cdot \left(b + a\right)}{\frac{a}{a - b} \cdot a}}} \]
    4. *-un-lft-identity100.0%

      \[\leadsto \sqrt{\frac{\color{blue}{b + a}}{\frac{a}{a - b} \cdot a}} \]
  8. Applied egg-rr100.0%

    \[\leadsto \sqrt{\color{blue}{\frac{b + a}{\frac{a}{a - b} \cdot a}}} \]
  9. Final simplification100.0%

    \[\leadsto \sqrt{\frac{b + a}{a \cdot \frac{a}{a - b}}} \]
  10. Add Preprocessing

Alternative 4: 100.0% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \sqrt{\frac{b + a}{a} \cdot \frac{a - b}{a}} \end{array} \]
(FPCore (a b) :precision binary64 (sqrt (* (/ (+ b a) a) (/ (- a b) a))))
double code(double a, double b) {
	return sqrt((((b + a) / a) * ((a - b) / a)));
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = sqrt((((b + a) / a) * ((a - b) / a)))
end function
public static double code(double a, double b) {
	return Math.sqrt((((b + a) / a) * ((a - b) / a)));
}
def code(a, b):
	return math.sqrt((((b + a) / a) * ((a - b) / a)))
function code(a, b)
	return sqrt(Float64(Float64(Float64(b + a) / a) * Float64(Float64(a - b) / a)))
end
function tmp = code(a, b)
	tmp = sqrt((((b + a) / a) * ((a - b) / a)));
end
code[a_, b_] := N[Sqrt[N[(N[(N[(b + a), $MachinePrecision] / a), $MachinePrecision] * N[(N[(a - b), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\sqrt{\frac{b + a}{a} \cdot \frac{a - b}{a}}
\end{array}
Derivation
  1. Initial program 79.3%

    \[\sqrt{\left|\frac{a \cdot a - b \cdot b}{a \cdot a}\right|} \]
  2. Step-by-step derivation
    1. sqr-neg79.3%

      \[\leadsto \sqrt{\left|\frac{a \cdot a - \color{blue}{\left(-b\right) \cdot \left(-b\right)}}{a \cdot a}\right|} \]
    2. associate-/r*78.7%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{\frac{a \cdot a - \left(-b\right) \cdot \left(-b\right)}{a}}{a}}\right|} \]
    3. sqr-neg78.7%

      \[\leadsto \sqrt{\left|\frac{\frac{a \cdot a - \color{blue}{b \cdot b}}{a}}{a}\right|} \]
    4. associate-/r*79.3%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{a \cdot a - b \cdot b}{a \cdot a}}\right|} \]
    5. div-sub79.3%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{a \cdot a}{a \cdot a} - \frac{b \cdot b}{a \cdot a}}\right|} \]
    6. fabs-sub79.3%

      \[\leadsto \sqrt{\color{blue}{\left|\frac{b \cdot b}{a \cdot a} - \frac{a \cdot a}{a \cdot a}\right|}} \]
    7. times-frac79.3%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{b}{a} \cdot \frac{b}{a}} - \frac{a \cdot a}{a \cdot a}\right|} \]
    8. *-inverses100.0%

      \[\leadsto \sqrt{\left|\frac{b}{a} \cdot \frac{b}{a} - \color{blue}{1}\right|} \]
    9. difference-of-sqr-199.9%

      \[\leadsto \sqrt{\left|\color{blue}{\left(\frac{b}{a} + 1\right) \cdot \left(\frac{b}{a} - 1\right)}\right|} \]
    10. difference-of-sqr--1100.0%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{b}{a} \cdot \frac{b}{a} + -1}\right|} \]
    11. fma-define100.0%

      \[\leadsto \sqrt{\left|\color{blue}{\mathsf{fma}\left(\frac{b}{a}, \frac{b}{a}, -1\right)}\right|} \]
  3. Simplified100.0%

    \[\leadsto \color{blue}{\sqrt{\left|\mathsf{fma}\left(\frac{b}{a}, \frac{b}{a}, -1\right)\right|}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. add-sqr-sqrt100.0%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\frac{\color{blue}{\sqrt{b} \cdot \sqrt{b}}}{a}, \frac{b}{a}, -1\right)\right|} \]
    2. associate-/l*100.0%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\color{blue}{\sqrt{b} \cdot \frac{\sqrt{b}}{a}}, \frac{b}{a}, -1\right)\right|} \]
    3. add-sqr-sqrt100.0%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b} \cdot \frac{\sqrt{b}}{\color{blue}{\sqrt{a} \cdot \sqrt{a}}}, \frac{b}{a}, -1\right)\right|} \]
    4. sqrt-prod79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b} \cdot \frac{\sqrt{b}}{\color{blue}{\sqrt{a \cdot a}}}, \frac{b}{a}, -1\right)\right|} \]
    5. sqrt-div79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b} \cdot \color{blue}{\sqrt{\frac{b}{a \cdot a}}}, \frac{b}{a}, -1\right)\right|} \]
    6. sqrt-prod79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\color{blue}{\sqrt{b \cdot \frac{b}{a \cdot a}}}, \frac{b}{a}, -1\right)\right|} \]
    7. add-sqr-sqrt79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \frac{\color{blue}{\sqrt{b} \cdot \sqrt{b}}}{a}, -1\right)\right|} \]
    8. associate-/l*79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \color{blue}{\sqrt{b} \cdot \frac{\sqrt{b}}{a}}, -1\right)\right|} \]
    9. add-sqr-sqrt79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \sqrt{b} \cdot \frac{\sqrt{b}}{\color{blue}{\sqrt{a} \cdot \sqrt{a}}}, -1\right)\right|} \]
    10. sqrt-prod79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \sqrt{b} \cdot \frac{\sqrt{b}}{\color{blue}{\sqrt{a \cdot a}}}, -1\right)\right|} \]
    11. sqrt-div79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \sqrt{b} \cdot \color{blue}{\sqrt{\frac{b}{a \cdot a}}}, -1\right)\right|} \]
    12. sqrt-prod79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \color{blue}{\sqrt{b \cdot \frac{b}{a \cdot a}}}, -1\right)\right|} \]
    13. metadata-eval79.9%

      \[\leadsto \sqrt{\left|\mathsf{fma}\left(\sqrt{b \cdot \frac{b}{a \cdot a}}, \sqrt{b \cdot \frac{b}{a \cdot a}}, \color{blue}{-1}\right)\right|} \]
    14. fmm-def79.9%

      \[\leadsto \sqrt{\left|\color{blue}{\sqrt{b \cdot \frac{b}{a \cdot a}} \cdot \sqrt{b \cdot \frac{b}{a \cdot a}} - 1}\right|} \]
    15. add-sqr-sqrt79.9%

      \[\leadsto \sqrt{\left|\color{blue}{b \cdot \frac{b}{a \cdot a}} - 1\right|} \]
    16. fabs-sub79.9%

      \[\leadsto \sqrt{\color{blue}{\left|1 - b \cdot \frac{b}{a \cdot a}\right|}} \]
    17. *-inverses79.3%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{a \cdot a}{a \cdot a}} - b \cdot \frac{b}{a \cdot a}\right|} \]
    18. associate-*r/79.3%

      \[\leadsto \sqrt{\left|\frac{a \cdot a}{a \cdot a} - \color{blue}{\frac{b \cdot b}{a \cdot a}}\right|} \]
  6. Applied egg-rr99.9%

    \[\leadsto \sqrt{\color{blue}{\frac{b + a}{a} \cdot \frac{a - b}{a}}} \]
  7. Add Preprocessing

Alternative 5: 98.0% accurate, 211.0× speedup?

\[\begin{array}{l} \\ 1 \end{array} \]
(FPCore (a b) :precision binary64 1.0)
double code(double a, double b) {
	return 1.0;
}
real(8) function code(a, b)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    code = 1.0d0
end function
public static double code(double a, double b) {
	return 1.0;
}
def code(a, b):
	return 1.0
function code(a, b)
	return 1.0
end
function tmp = code(a, b)
	tmp = 1.0;
end
code[a_, b_] := 1.0
\begin{array}{l}

\\
1
\end{array}
Derivation
  1. Initial program 79.3%

    \[\sqrt{\left|\frac{a \cdot a - b \cdot b}{a \cdot a}\right|} \]
  2. Step-by-step derivation
    1. sqr-neg79.3%

      \[\leadsto \sqrt{\left|\frac{a \cdot a - \color{blue}{\left(-b\right) \cdot \left(-b\right)}}{a \cdot a}\right|} \]
    2. fabs-div79.3%

      \[\leadsto \sqrt{\color{blue}{\frac{\left|a \cdot a - \left(-b\right) \cdot \left(-b\right)\right|}{\left|a \cdot a\right|}}} \]
    3. sqr-neg79.3%

      \[\leadsto \sqrt{\frac{\left|a \cdot a - \color{blue}{b \cdot b}\right|}{\left|a \cdot a\right|}} \]
    4. fabs-sub79.3%

      \[\leadsto \sqrt{\frac{\color{blue}{\left|b \cdot b - a \cdot a\right|}}{\left|a \cdot a\right|}} \]
    5. sqr-neg79.3%

      \[\leadsto \sqrt{\frac{\left|b \cdot b - a \cdot a\right|}{\left|\color{blue}{\left(-a\right) \cdot \left(-a\right)}\right|}} \]
    6. distribute-rgt-neg-out79.3%

      \[\leadsto \sqrt{\frac{\left|b \cdot b - a \cdot a\right|}{\left|\color{blue}{-\left(-a\right) \cdot a}\right|}} \]
    7. fabs-neg79.3%

      \[\leadsto \sqrt{\frac{\left|b \cdot b - a \cdot a\right|}{\color{blue}{\left|\left(-a\right) \cdot a\right|}}} \]
    8. fabs-div79.3%

      \[\leadsto \sqrt{\color{blue}{\left|\frac{b \cdot b - a \cdot a}{\left(-a\right) \cdot a}\right|}} \]
    9. cancel-sign-sub-inv79.3%

      \[\leadsto \sqrt{\left|\frac{\color{blue}{b \cdot b + \left(-a\right) \cdot a}}{\left(-a\right) \cdot a}\right|} \]
    10. +-commutative79.3%

      \[\leadsto \sqrt{\left|\frac{\color{blue}{\left(-a\right) \cdot a + b \cdot b}}{\left(-a\right) \cdot a}\right|} \]
    11. sqr-neg79.3%

      \[\leadsto \sqrt{\left|\frac{\left(-a\right) \cdot a + \color{blue}{\left(-b\right) \cdot \left(-b\right)}}{\left(-a\right) \cdot a}\right|} \]
    12. cancel-sign-sub-inv79.3%

      \[\leadsto \sqrt{\left|\frac{\color{blue}{\left(-a\right) \cdot a - b \cdot \left(-b\right)}}{\left(-a\right) \cdot a}\right|} \]
    13. div-sub79.3%

      \[\leadsto \sqrt{\left|\color{blue}{\frac{\left(-a\right) \cdot a}{\left(-a\right) \cdot a} - \frac{b \cdot \left(-b\right)}{\left(-a\right) \cdot a}}\right|} \]
  3. Simplified79.9%

    \[\leadsto \color{blue}{\sqrt{\left|1 - b \cdot \frac{b}{a \cdot a}\right|}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. pow1/279.9%

      \[\leadsto \color{blue}{{\left(\left|1 - b \cdot \frac{b}{a \cdot a}\right|\right)}^{0.5}} \]
    2. pow-to-exp79.9%

      \[\leadsto \color{blue}{e^{\log \left(\left|1 - b \cdot \frac{b}{a \cdot a}\right|\right) \cdot 0.5}} \]
    3. add-sqr-sqrt79.3%

      \[\leadsto e^{\log \left(\left|\color{blue}{\sqrt{1 - b \cdot \frac{b}{a \cdot a}} \cdot \sqrt{1 - b \cdot \frac{b}{a \cdot a}}}\right|\right) \cdot 0.5} \]
    4. fabs-sqr79.3%

      \[\leadsto e^{\log \color{blue}{\left(\sqrt{1 - b \cdot \frac{b}{a \cdot a}} \cdot \sqrt{1 - b \cdot \frac{b}{a \cdot a}}\right)} \cdot 0.5} \]
    5. add-sqr-sqrt79.3%

      \[\leadsto e^{\log \color{blue}{\left(1 - b \cdot \frac{b}{a \cdot a}\right)} \cdot 0.5} \]
    6. sub-neg79.3%

      \[\leadsto e^{\log \color{blue}{\left(1 + \left(-b \cdot \frac{b}{a \cdot a}\right)\right)} \cdot 0.5} \]
    7. log1p-define79.3%

      \[\leadsto e^{\color{blue}{\mathsf{log1p}\left(-b \cdot \frac{b}{a \cdot a}\right)} \cdot 0.5} \]
    8. associate-*r/79.3%

      \[\leadsto e^{\mathsf{log1p}\left(-\color{blue}{\frac{b \cdot b}{a \cdot a}}\right) \cdot 0.5} \]
    9. frac-times100.0%

      \[\leadsto e^{\mathsf{log1p}\left(-\color{blue}{\frac{b}{a} \cdot \frac{b}{a}}\right) \cdot 0.5} \]
    10. pow2100.0%

      \[\leadsto e^{\mathsf{log1p}\left(-\color{blue}{{\left(\frac{b}{a}\right)}^{2}}\right) \cdot 0.5} \]
  6. Applied egg-rr100.0%

    \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(-{\left(\frac{b}{a}\right)}^{2}\right) \cdot 0.5}} \]
  7. Taylor expanded in b around 0 98.0%

    \[\leadsto \color{blue}{1} \]
  8. Add Preprocessing

Reproduce

?
herbie shell --seed 2024186 
(FPCore (a b)
  :name "Eccentricity of an ellipse"
  :precision binary64
  :pre (and (and (<= 0.0 b) (<= b a)) (<= a 1.0))
  (sqrt (fabs (/ (- (* a a) (* b b)) (* a a)))))