Optimal throwing angle

Percentage Accurate: 67.0% → 99.6%
Time: 6.3s
Alternatives: 6
Speedup: 1.3×

Specification

?
\[\begin{array}{l} \\ \tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \end{array} \]
(FPCore (v H)
 :precision binary64
 (atan (/ v (sqrt (- (* v v) (* (* 2.0 9.8) H))))))
double code(double v, double H) {
	return atan((v / sqrt(((v * v) - ((2.0 * 9.8) * H)))));
}
real(8) function code(v, h)
    real(8), intent (in) :: v
    real(8), intent (in) :: h
    code = atan((v / sqrt(((v * v) - ((2.0d0 * 9.8d0) * h)))))
end function
public static double code(double v, double H) {
	return Math.atan((v / Math.sqrt(((v * v) - ((2.0 * 9.8) * H)))));
}
def code(v, H):
	return math.atan((v / math.sqrt(((v * v) - ((2.0 * 9.8) * H)))))
function code(v, H)
	return atan(Float64(v / sqrt(Float64(Float64(v * v) - Float64(Float64(2.0 * 9.8) * H)))))
end
function tmp = code(v, H)
	tmp = atan((v / sqrt(((v * v) - ((2.0 * 9.8) * H)))));
end
code[v_, H_] := N[ArcTan[N[(v / N[Sqrt[N[(N[(v * v), $MachinePrecision] - N[(N[(2.0 * 9.8), $MachinePrecision] * H), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\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 6 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: 67.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \end{array} \]
(FPCore (v H)
 :precision binary64
 (atan (/ v (sqrt (- (* v v) (* (* 2.0 9.8) H))))))
double code(double v, double H) {
	return atan((v / sqrt(((v * v) - ((2.0 * 9.8) * H)))));
}
real(8) function code(v, h)
    real(8), intent (in) :: v
    real(8), intent (in) :: h
    code = atan((v / sqrt(((v * v) - ((2.0d0 * 9.8d0) * h)))))
end function
public static double code(double v, double H) {
	return Math.atan((v / Math.sqrt(((v * v) - ((2.0 * 9.8) * H)))));
}
def code(v, H):
	return math.atan((v / math.sqrt(((v * v) - ((2.0 * 9.8) * H)))))
function code(v, H)
	return atan(Float64(v / sqrt(Float64(Float64(v * v) - Float64(Float64(2.0 * 9.8) * H)))))
end
function tmp = code(v, H)
	tmp = atan((v / sqrt(((v * v) - ((2.0 * 9.8) * H)))));
end
code[v_, H_] := N[ArcTan[N[(v / N[Sqrt[N[(N[(v * v), $MachinePrecision] - N[(N[(2.0 * 9.8), $MachinePrecision] * H), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right)
\end{array}

Alternative 1: 99.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;v \leq -2 \cdot 10^{+155}:\\ \;\;\;\;\tan^{-1} -1\\ \mathbf{elif}\;v \leq 2.5 \cdot 10^{+136}:\\ \;\;\;\;\tan^{-1} \left(\frac{v}{\sqrt{\mathsf{fma}\left(v, v, -19.6 \cdot H\right)}}\right)\\ \mathbf{else}:\\ \;\;\;\;\tan^{-1} 1\\ \end{array} \end{array} \]
(FPCore (v H)
 :precision binary64
 (if (<= v -2e+155)
   (atan -1.0)
   (if (<= v 2.5e+136) (atan (/ v (sqrt (fma v v (* -19.6 H))))) (atan 1.0))))
double code(double v, double H) {
	double tmp;
	if (v <= -2e+155) {
		tmp = atan(-1.0);
	} else if (v <= 2.5e+136) {
		tmp = atan((v / sqrt(fma(v, v, (-19.6 * H)))));
	} else {
		tmp = atan(1.0);
	}
	return tmp;
}
function code(v, H)
	tmp = 0.0
	if (v <= -2e+155)
		tmp = atan(-1.0);
	elseif (v <= 2.5e+136)
		tmp = atan(Float64(v / sqrt(fma(v, v, Float64(-19.6 * H)))));
	else
		tmp = atan(1.0);
	end
	return tmp
end
code[v_, H_] := If[LessEqual[v, -2e+155], N[ArcTan[-1.0], $MachinePrecision], If[LessEqual[v, 2.5e+136], N[ArcTan[N[(v / N[Sqrt[N[(v * v + N[(-19.6 * H), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[ArcTan[1.0], $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;v \leq -2 \cdot 10^{+155}:\\
\;\;\;\;\tan^{-1} -1\\

\mathbf{elif}\;v \leq 2.5 \cdot 10^{+136}:\\
\;\;\;\;\tan^{-1} \left(\frac{v}{\sqrt{\mathsf{fma}\left(v, v, -19.6 \cdot H\right)}}\right)\\

\mathbf{else}:\\
\;\;\;\;\tan^{-1} 1\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if v < -2.00000000000000001e155

    1. Initial program 3.1%

      \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in v around -inf

      \[\leadsto \tan^{-1} \color{blue}{-1} \]
    4. Step-by-step derivation
      1. Applied rewrites100.0%

        \[\leadsto \tan^{-1} \color{blue}{-1} \]

      if -2.00000000000000001e155 < v < 2.5000000000000001e136

      1. Initial program 99.7%

        \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift--.f64N/A

          \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\color{blue}{v \cdot v - \left(2 \cdot \frac{49}{5}\right) \cdot H}}}\right) \]
        2. sub-negN/A

          \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\color{blue}{v \cdot v + \left(\mathsf{neg}\left(\left(2 \cdot \frac{49}{5}\right) \cdot H\right)\right)}}}\right) \]
        3. lift-*.f64N/A

          \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\color{blue}{v \cdot v} + \left(\mathsf{neg}\left(\left(2 \cdot \frac{49}{5}\right) \cdot H\right)\right)}}\right) \]
        4. lower-fma.f64N/A

          \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\color{blue}{\mathsf{fma}\left(v, v, \mathsf{neg}\left(\left(2 \cdot \frac{49}{5}\right) \cdot H\right)\right)}}}\right) \]
        5. lift-*.f64N/A

          \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\mathsf{fma}\left(v, v, \mathsf{neg}\left(\color{blue}{\left(2 \cdot \frac{49}{5}\right) \cdot H}\right)\right)}}\right) \]
        6. distribute-lft-neg-inN/A

          \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\mathsf{fma}\left(v, v, \color{blue}{\left(\mathsf{neg}\left(2 \cdot \frac{49}{5}\right)\right) \cdot H}\right)}}\right) \]
        7. lower-*.f64N/A

          \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\mathsf{fma}\left(v, v, \color{blue}{\left(\mathsf{neg}\left(2 \cdot \frac{49}{5}\right)\right) \cdot H}\right)}}\right) \]
        8. lift-*.f64N/A

          \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\mathsf{fma}\left(v, v, \left(\mathsf{neg}\left(\color{blue}{2 \cdot \frac{49}{5}}\right)\right) \cdot H\right)}}\right) \]
        9. metadata-evalN/A

          \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\mathsf{fma}\left(v, v, \left(\mathsf{neg}\left(\color{blue}{\frac{98}{5}}\right)\right) \cdot H\right)}}\right) \]
        10. metadata-eval99.7

          \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\mathsf{fma}\left(v, v, \color{blue}{-19.6} \cdot H\right)}}\right) \]
      4. Applied rewrites99.7%

        \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\color{blue}{\mathsf{fma}\left(v, v, -19.6 \cdot H\right)}}}\right) \]

      if 2.5000000000000001e136 < v

      1. Initial program 9.4%

        \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
      2. Add Preprocessing
      3. Taylor expanded in v around inf

        \[\leadsto \tan^{-1} \color{blue}{1} \]
      4. Step-by-step derivation
        1. Applied rewrites100.0%

          \[\leadsto \tan^{-1} \color{blue}{1} \]
      5. Recombined 3 regimes into one program.
      6. Add Preprocessing

      Alternative 2: 88.2% accurate, 1.0× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;v \leq -1.7 \cdot 10^{-114}:\\ \;\;\;\;\tan^{-1} -1\\ \mathbf{elif}\;v \leq 1.45 \cdot 10^{-37}:\\ \;\;\;\;\tan^{-1} \left(\frac{v}{\sqrt{-19.6 \cdot H}}\right)\\ \mathbf{else}:\\ \;\;\;\;\tan^{-1} \left(\frac{v}{\mathsf{fma}\left(\frac{-9.8}{v}, H, v\right)}\right)\\ \end{array} \end{array} \]
      (FPCore (v H)
       :precision binary64
       (if (<= v -1.7e-114)
         (atan -1.0)
         (if (<= v 1.45e-37)
           (atan (/ v (sqrt (* -19.6 H))))
           (atan (/ v (fma (/ -9.8 v) H v))))))
      double code(double v, double H) {
      	double tmp;
      	if (v <= -1.7e-114) {
      		tmp = atan(-1.0);
      	} else if (v <= 1.45e-37) {
      		tmp = atan((v / sqrt((-19.6 * H))));
      	} else {
      		tmp = atan((v / fma((-9.8 / v), H, v)));
      	}
      	return tmp;
      }
      
      function code(v, H)
      	tmp = 0.0
      	if (v <= -1.7e-114)
      		tmp = atan(-1.0);
      	elseif (v <= 1.45e-37)
      		tmp = atan(Float64(v / sqrt(Float64(-19.6 * H))));
      	else
      		tmp = atan(Float64(v / fma(Float64(-9.8 / v), H, v)));
      	end
      	return tmp
      end
      
      code[v_, H_] := If[LessEqual[v, -1.7e-114], N[ArcTan[-1.0], $MachinePrecision], If[LessEqual[v, 1.45e-37], N[ArcTan[N[(v / N[Sqrt[N[(-19.6 * H), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[ArcTan[N[(v / N[(N[(-9.8 / v), $MachinePrecision] * H + v), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;v \leq -1.7 \cdot 10^{-114}:\\
      \;\;\;\;\tan^{-1} -1\\
      
      \mathbf{elif}\;v \leq 1.45 \cdot 10^{-37}:\\
      \;\;\;\;\tan^{-1} \left(\frac{v}{\sqrt{-19.6 \cdot H}}\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\tan^{-1} \left(\frac{v}{\mathsf{fma}\left(\frac{-9.8}{v}, H, v\right)}\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 3 regimes
      2. if v < -1.69999999999999991e-114

        1. Initial program 59.7%

          \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
        2. Add Preprocessing
        3. Taylor expanded in v around -inf

          \[\leadsto \tan^{-1} \color{blue}{-1} \]
        4. Step-by-step derivation
          1. Applied rewrites83.7%

            \[\leadsto \tan^{-1} \color{blue}{-1} \]

          if -1.69999999999999991e-114 < v < 1.45000000000000002e-37

          1. Initial program 99.6%

            \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
          2. Add Preprocessing
          3. Taylor expanded in v around 0

            \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\color{blue}{\frac{-98}{5} \cdot H}}}\right) \]
          4. Step-by-step derivation
            1. lower-*.f6493.3

              \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\color{blue}{-19.6 \cdot H}}}\right) \]
          5. Applied rewrites93.3%

            \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\color{blue}{-19.6 \cdot H}}}\right) \]

          if 1.45000000000000002e-37 < v

          1. Initial program 47.8%

            \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
          2. Add Preprocessing
          3. Taylor expanded in H around 0

            \[\leadsto \tan^{-1} \left(\frac{v}{\color{blue}{v + \frac{-49}{5} \cdot \frac{H}{v}}}\right) \]
          4. Step-by-step derivation
            1. +-commutativeN/A

              \[\leadsto \tan^{-1} \left(\frac{v}{\color{blue}{\frac{-49}{5} \cdot \frac{H}{v} + v}}\right) \]
            2. associate-*r/N/A

              \[\leadsto \tan^{-1} \left(\frac{v}{\color{blue}{\frac{\frac{-49}{5} \cdot H}{v}} + v}\right) \]
            3. associate-*l/N/A

              \[\leadsto \tan^{-1} \left(\frac{v}{\color{blue}{\frac{\frac{-49}{5}}{v} \cdot H} + v}\right) \]
            4. metadata-evalN/A

              \[\leadsto \tan^{-1} \left(\frac{v}{\frac{\color{blue}{\mathsf{neg}\left(\frac{49}{5}\right)}}{v} \cdot H + v}\right) \]
            5. distribute-neg-fracN/A

              \[\leadsto \tan^{-1} \left(\frac{v}{\color{blue}{\left(\mathsf{neg}\left(\frac{\frac{49}{5}}{v}\right)\right)} \cdot H + v}\right) \]
            6. metadata-evalN/A

              \[\leadsto \tan^{-1} \left(\frac{v}{\left(\mathsf{neg}\left(\frac{\color{blue}{\frac{49}{5} \cdot 1}}{v}\right)\right) \cdot H + v}\right) \]
            7. associate-*r/N/A

              \[\leadsto \tan^{-1} \left(\frac{v}{\left(\mathsf{neg}\left(\color{blue}{\frac{49}{5} \cdot \frac{1}{v}}\right)\right) \cdot H + v}\right) \]
            8. lower-fma.f64N/A

              \[\leadsto \tan^{-1} \left(\frac{v}{\color{blue}{\mathsf{fma}\left(\mathsf{neg}\left(\frac{49}{5} \cdot \frac{1}{v}\right), H, v\right)}}\right) \]
            9. associate-*r/N/A

              \[\leadsto \tan^{-1} \left(\frac{v}{\mathsf{fma}\left(\mathsf{neg}\left(\color{blue}{\frac{\frac{49}{5} \cdot 1}{v}}\right), H, v\right)}\right) \]
            10. metadata-evalN/A

              \[\leadsto \tan^{-1} \left(\frac{v}{\mathsf{fma}\left(\mathsf{neg}\left(\frac{\color{blue}{\frac{49}{5}}}{v}\right), H, v\right)}\right) \]
            11. distribute-neg-fracN/A

              \[\leadsto \tan^{-1} \left(\frac{v}{\mathsf{fma}\left(\color{blue}{\frac{\mathsf{neg}\left(\frac{49}{5}\right)}{v}}, H, v\right)}\right) \]
            12. metadata-evalN/A

              \[\leadsto \tan^{-1} \left(\frac{v}{\mathsf{fma}\left(\frac{\color{blue}{\frac{-49}{5}}}{v}, H, v\right)}\right) \]
            13. lower-/.f6491.0

              \[\leadsto \tan^{-1} \left(\frac{v}{\mathsf{fma}\left(\color{blue}{\frac{-9.8}{v}}, H, v\right)}\right) \]
          5. Applied rewrites91.0%

            \[\leadsto \tan^{-1} \left(\frac{v}{\color{blue}{\mathsf{fma}\left(\frac{-9.8}{v}, H, v\right)}}\right) \]
        5. Recombined 3 regimes into one program.
        6. Add Preprocessing

        Alternative 3: 88.1% accurate, 1.0× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;v \leq -1.7 \cdot 10^{-114}:\\ \;\;\;\;\tan^{-1} -1\\ \mathbf{elif}\;v \leq 1.45 \cdot 10^{-37}:\\ \;\;\;\;\tan^{-1} \left(\frac{v}{\sqrt{-19.6 \cdot H}}\right)\\ \mathbf{else}:\\ \;\;\;\;\tan^{-1} 1\\ \end{array} \end{array} \]
        (FPCore (v H)
         :precision binary64
         (if (<= v -1.7e-114)
           (atan -1.0)
           (if (<= v 1.45e-37) (atan (/ v (sqrt (* -19.6 H)))) (atan 1.0))))
        double code(double v, double H) {
        	double tmp;
        	if (v <= -1.7e-114) {
        		tmp = atan(-1.0);
        	} else if (v <= 1.45e-37) {
        		tmp = atan((v / sqrt((-19.6 * H))));
        	} else {
        		tmp = atan(1.0);
        	}
        	return tmp;
        }
        
        real(8) function code(v, h)
            real(8), intent (in) :: v
            real(8), intent (in) :: h
            real(8) :: tmp
            if (v <= (-1.7d-114)) then
                tmp = atan((-1.0d0))
            else if (v <= 1.45d-37) then
                tmp = atan((v / sqrt(((-19.6d0) * h))))
            else
                tmp = atan(1.0d0)
            end if
            code = tmp
        end function
        
        public static double code(double v, double H) {
        	double tmp;
        	if (v <= -1.7e-114) {
        		tmp = Math.atan(-1.0);
        	} else if (v <= 1.45e-37) {
        		tmp = Math.atan((v / Math.sqrt((-19.6 * H))));
        	} else {
        		tmp = Math.atan(1.0);
        	}
        	return tmp;
        }
        
        def code(v, H):
        	tmp = 0
        	if v <= -1.7e-114:
        		tmp = math.atan(-1.0)
        	elif v <= 1.45e-37:
        		tmp = math.atan((v / math.sqrt((-19.6 * H))))
        	else:
        		tmp = math.atan(1.0)
        	return tmp
        
        function code(v, H)
        	tmp = 0.0
        	if (v <= -1.7e-114)
        		tmp = atan(-1.0);
        	elseif (v <= 1.45e-37)
        		tmp = atan(Float64(v / sqrt(Float64(-19.6 * H))));
        	else
        		tmp = atan(1.0);
        	end
        	return tmp
        end
        
        function tmp_2 = code(v, H)
        	tmp = 0.0;
        	if (v <= -1.7e-114)
        		tmp = atan(-1.0);
        	elseif (v <= 1.45e-37)
        		tmp = atan((v / sqrt((-19.6 * H))));
        	else
        		tmp = atan(1.0);
        	end
        	tmp_2 = tmp;
        end
        
        code[v_, H_] := If[LessEqual[v, -1.7e-114], N[ArcTan[-1.0], $MachinePrecision], If[LessEqual[v, 1.45e-37], N[ArcTan[N[(v / N[Sqrt[N[(-19.6 * H), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[ArcTan[1.0], $MachinePrecision]]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;v \leq -1.7 \cdot 10^{-114}:\\
        \;\;\;\;\tan^{-1} -1\\
        
        \mathbf{elif}\;v \leq 1.45 \cdot 10^{-37}:\\
        \;\;\;\;\tan^{-1} \left(\frac{v}{\sqrt{-19.6 \cdot H}}\right)\\
        
        \mathbf{else}:\\
        \;\;\;\;\tan^{-1} 1\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 3 regimes
        2. if v < -1.69999999999999991e-114

          1. Initial program 59.7%

            \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
          2. Add Preprocessing
          3. Taylor expanded in v around -inf

            \[\leadsto \tan^{-1} \color{blue}{-1} \]
          4. Step-by-step derivation
            1. Applied rewrites83.7%

              \[\leadsto \tan^{-1} \color{blue}{-1} \]

            if -1.69999999999999991e-114 < v < 1.45000000000000002e-37

            1. Initial program 99.6%

              \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
            2. Add Preprocessing
            3. Taylor expanded in v around 0

              \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\color{blue}{\frac{-98}{5} \cdot H}}}\right) \]
            4. Step-by-step derivation
              1. lower-*.f6493.3

                \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\color{blue}{-19.6 \cdot H}}}\right) \]
            5. Applied rewrites93.3%

              \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\color{blue}{-19.6 \cdot H}}}\right) \]

            if 1.45000000000000002e-37 < v

            1. Initial program 47.8%

              \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
            2. Add Preprocessing
            3. Taylor expanded in v around inf

              \[\leadsto \tan^{-1} \color{blue}{1} \]
            4. Step-by-step derivation
              1. Applied rewrites90.2%

                \[\leadsto \tan^{-1} \color{blue}{1} \]
            5. Recombined 3 regimes into one program.
            6. Add Preprocessing

            Alternative 4: 88.1% accurate, 1.0× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;v \leq -1.7 \cdot 10^{-114}:\\ \;\;\;\;\tan^{-1} -1\\ \mathbf{elif}\;v \leq 1.45 \cdot 10^{-37}:\\ \;\;\;\;\tan^{-1} \left(\sqrt{\frac{-0.05102040816326531}{H}} \cdot v\right)\\ \mathbf{else}:\\ \;\;\;\;\tan^{-1} 1\\ \end{array} \end{array} \]
            (FPCore (v H)
             :precision binary64
             (if (<= v -1.7e-114)
               (atan -1.0)
               (if (<= v 1.45e-37)
                 (atan (* (sqrt (/ -0.05102040816326531 H)) v))
                 (atan 1.0))))
            double code(double v, double H) {
            	double tmp;
            	if (v <= -1.7e-114) {
            		tmp = atan(-1.0);
            	} else if (v <= 1.45e-37) {
            		tmp = atan((sqrt((-0.05102040816326531 / H)) * v));
            	} else {
            		tmp = atan(1.0);
            	}
            	return tmp;
            }
            
            real(8) function code(v, h)
                real(8), intent (in) :: v
                real(8), intent (in) :: h
                real(8) :: tmp
                if (v <= (-1.7d-114)) then
                    tmp = atan((-1.0d0))
                else if (v <= 1.45d-37) then
                    tmp = atan((sqrt(((-0.05102040816326531d0) / h)) * v))
                else
                    tmp = atan(1.0d0)
                end if
                code = tmp
            end function
            
            public static double code(double v, double H) {
            	double tmp;
            	if (v <= -1.7e-114) {
            		tmp = Math.atan(-1.0);
            	} else if (v <= 1.45e-37) {
            		tmp = Math.atan((Math.sqrt((-0.05102040816326531 / H)) * v));
            	} else {
            		tmp = Math.atan(1.0);
            	}
            	return tmp;
            }
            
            def code(v, H):
            	tmp = 0
            	if v <= -1.7e-114:
            		tmp = math.atan(-1.0)
            	elif v <= 1.45e-37:
            		tmp = math.atan((math.sqrt((-0.05102040816326531 / H)) * v))
            	else:
            		tmp = math.atan(1.0)
            	return tmp
            
            function code(v, H)
            	tmp = 0.0
            	if (v <= -1.7e-114)
            		tmp = atan(-1.0);
            	elseif (v <= 1.45e-37)
            		tmp = atan(Float64(sqrt(Float64(-0.05102040816326531 / H)) * v));
            	else
            		tmp = atan(1.0);
            	end
            	return tmp
            end
            
            function tmp_2 = code(v, H)
            	tmp = 0.0;
            	if (v <= -1.7e-114)
            		tmp = atan(-1.0);
            	elseif (v <= 1.45e-37)
            		tmp = atan((sqrt((-0.05102040816326531 / H)) * v));
            	else
            		tmp = atan(1.0);
            	end
            	tmp_2 = tmp;
            end
            
            code[v_, H_] := If[LessEqual[v, -1.7e-114], N[ArcTan[-1.0], $MachinePrecision], If[LessEqual[v, 1.45e-37], N[ArcTan[N[(N[Sqrt[N[(-0.05102040816326531 / H), $MachinePrecision]], $MachinePrecision] * v), $MachinePrecision]], $MachinePrecision], N[ArcTan[1.0], $MachinePrecision]]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            \mathbf{if}\;v \leq -1.7 \cdot 10^{-114}:\\
            \;\;\;\;\tan^{-1} -1\\
            
            \mathbf{elif}\;v \leq 1.45 \cdot 10^{-37}:\\
            \;\;\;\;\tan^{-1} \left(\sqrt{\frac{-0.05102040816326531}{H}} \cdot v\right)\\
            
            \mathbf{else}:\\
            \;\;\;\;\tan^{-1} 1\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 3 regimes
            2. if v < -1.69999999999999991e-114

              1. Initial program 59.7%

                \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
              2. Add Preprocessing
              3. Taylor expanded in v around -inf

                \[\leadsto \tan^{-1} \color{blue}{-1} \]
              4. Step-by-step derivation
                1. Applied rewrites83.7%

                  \[\leadsto \tan^{-1} \color{blue}{-1} \]

                if -1.69999999999999991e-114 < v < 1.45000000000000002e-37

                1. Initial program 99.6%

                  \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
                2. Add Preprocessing
                3. Taylor expanded in v around 0

                  \[\leadsto \color{blue}{\tan^{-1} \left(v \cdot \sqrt{\frac{1}{{v}^{2} - \frac{98}{5} \cdot H}}\right)} \]
                4. Step-by-step derivation
                  1. cancel-sign-sub-invN/A

                    \[\leadsto \tan^{-1} \left(v \cdot \sqrt{\frac{1}{\color{blue}{{v}^{2} + \left(\mathsf{neg}\left(\frac{98}{5}\right)\right) \cdot H}}}\right) \]
                  2. metadata-evalN/A

                    \[\leadsto \tan^{-1} \left(v \cdot \sqrt{\frac{1}{{v}^{2} + \color{blue}{\frac{-98}{5}} \cdot H}}\right) \]
                  3. +-commutativeN/A

                    \[\leadsto \tan^{-1} \left(v \cdot \sqrt{\frac{1}{\color{blue}{\frac{-98}{5} \cdot H + {v}^{2}}}}\right) \]
                  4. lower-atan.f64N/A

                    \[\leadsto \color{blue}{\tan^{-1} \left(v \cdot \sqrt{\frac{1}{\frac{-98}{5} \cdot H + {v}^{2}}}\right)} \]
                  5. *-commutativeN/A

                    \[\leadsto \tan^{-1} \color{blue}{\left(\sqrt{\frac{1}{\frac{-98}{5} \cdot H + {v}^{2}}} \cdot v\right)} \]
                  6. lower-*.f64N/A

                    \[\leadsto \tan^{-1} \color{blue}{\left(\sqrt{\frac{1}{\frac{-98}{5} \cdot H + {v}^{2}}} \cdot v\right)} \]
                  7. lower-sqrt.f64N/A

                    \[\leadsto \tan^{-1} \left(\color{blue}{\sqrt{\frac{1}{\frac{-98}{5} \cdot H + {v}^{2}}}} \cdot v\right) \]
                  8. lower-/.f64N/A

                    \[\leadsto \tan^{-1} \left(\sqrt{\color{blue}{\frac{1}{\frac{-98}{5} \cdot H + {v}^{2}}}} \cdot v\right) \]
                  9. lower-fma.f64N/A

                    \[\leadsto \tan^{-1} \left(\sqrt{\frac{1}{\color{blue}{\mathsf{fma}\left(\frac{-98}{5}, H, {v}^{2}\right)}}} \cdot v\right) \]
                  10. unpow2N/A

                    \[\leadsto \tan^{-1} \left(\sqrt{\frac{1}{\mathsf{fma}\left(\frac{-98}{5}, H, \color{blue}{v \cdot v}\right)}} \cdot v\right) \]
                  11. lower-*.f6499.5

                    \[\leadsto \tan^{-1} \left(\sqrt{\frac{1}{\mathsf{fma}\left(-19.6, H, \color{blue}{v \cdot v}\right)}} \cdot v\right) \]
                5. Applied rewrites99.5%

                  \[\leadsto \color{blue}{\tan^{-1} \left(\sqrt{\frac{1}{\mathsf{fma}\left(-19.6, H, v \cdot v\right)}} \cdot v\right)} \]
                6. Taylor expanded in v around 0

                  \[\leadsto \tan^{-1} \left(\sqrt{\frac{\frac{-5}{98}}{H}} \cdot v\right) \]
                7. Step-by-step derivation
                  1. Applied rewrites93.3%

                    \[\leadsto \tan^{-1} \left(\sqrt{\frac{-0.05102040816326531}{H}} \cdot v\right) \]

                  if 1.45000000000000002e-37 < v

                  1. Initial program 47.8%

                    \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
                  2. Add Preprocessing
                  3. Taylor expanded in v around inf

                    \[\leadsto \tan^{-1} \color{blue}{1} \]
                  4. Step-by-step derivation
                    1. Applied rewrites90.2%

                      \[\leadsto \tan^{-1} \color{blue}{1} \]
                  5. Recombined 3 regimes into one program.
                  6. Add Preprocessing

                  Alternative 5: 67.9% accurate, 1.3× speedup?

                  \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;v \leq -2.05 \cdot 10^{-285}:\\ \;\;\;\;\tan^{-1} -1\\ \mathbf{else}:\\ \;\;\;\;\tan^{-1} 1\\ \end{array} \end{array} \]
                  (FPCore (v H)
                   :precision binary64
                   (if (<= v -2.05e-285) (atan -1.0) (atan 1.0)))
                  double code(double v, double H) {
                  	double tmp;
                  	if (v <= -2.05e-285) {
                  		tmp = atan(-1.0);
                  	} else {
                  		tmp = atan(1.0);
                  	}
                  	return tmp;
                  }
                  
                  real(8) function code(v, h)
                      real(8), intent (in) :: v
                      real(8), intent (in) :: h
                      real(8) :: tmp
                      if (v <= (-2.05d-285)) then
                          tmp = atan((-1.0d0))
                      else
                          tmp = atan(1.0d0)
                      end if
                      code = tmp
                  end function
                  
                  public static double code(double v, double H) {
                  	double tmp;
                  	if (v <= -2.05e-285) {
                  		tmp = Math.atan(-1.0);
                  	} else {
                  		tmp = Math.atan(1.0);
                  	}
                  	return tmp;
                  }
                  
                  def code(v, H):
                  	tmp = 0
                  	if v <= -2.05e-285:
                  		tmp = math.atan(-1.0)
                  	else:
                  		tmp = math.atan(1.0)
                  	return tmp
                  
                  function code(v, H)
                  	tmp = 0.0
                  	if (v <= -2.05e-285)
                  		tmp = atan(-1.0);
                  	else
                  		tmp = atan(1.0);
                  	end
                  	return tmp
                  end
                  
                  function tmp_2 = code(v, H)
                  	tmp = 0.0;
                  	if (v <= -2.05e-285)
                  		tmp = atan(-1.0);
                  	else
                  		tmp = atan(1.0);
                  	end
                  	tmp_2 = tmp;
                  end
                  
                  code[v_, H_] := If[LessEqual[v, -2.05e-285], N[ArcTan[-1.0], $MachinePrecision], N[ArcTan[1.0], $MachinePrecision]]
                  
                  \begin{array}{l}
                  
                  \\
                  \begin{array}{l}
                  \mathbf{if}\;v \leq -2.05 \cdot 10^{-285}:\\
                  \;\;\;\;\tan^{-1} -1\\
                  
                  \mathbf{else}:\\
                  \;\;\;\;\tan^{-1} 1\\
                  
                  
                  \end{array}
                  \end{array}
                  
                  Derivation
                  1. Split input into 2 regimes
                  2. if v < -2.05e-285

                    1. Initial program 66.3%

                      \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
                    2. Add Preprocessing
                    3. Taylor expanded in v around -inf

                      \[\leadsto \tan^{-1} \color{blue}{-1} \]
                    4. Step-by-step derivation
                      1. Applied rewrites70.6%

                        \[\leadsto \tan^{-1} \color{blue}{-1} \]

                      if -2.05e-285 < v

                      1. Initial program 67.5%

                        \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
                      2. Add Preprocessing
                      3. Taylor expanded in v around inf

                        \[\leadsto \tan^{-1} \color{blue}{1} \]
                      4. Step-by-step derivation
                        1. Applied rewrites60.3%

                          \[\leadsto \tan^{-1} \color{blue}{1} \]
                      5. Recombined 2 regimes into one program.
                      6. Add Preprocessing

                      Alternative 6: 35.2% accurate, 1.4× speedup?

                      \[\begin{array}{l} \\ \tan^{-1} -1 \end{array} \]
                      (FPCore (v H) :precision binary64 (atan -1.0))
                      double code(double v, double H) {
                      	return atan(-1.0);
                      }
                      
                      real(8) function code(v, h)
                          real(8), intent (in) :: v
                          real(8), intent (in) :: h
                          code = atan((-1.0d0))
                      end function
                      
                      public static double code(double v, double H) {
                      	return Math.atan(-1.0);
                      }
                      
                      def code(v, H):
                      	return math.atan(-1.0)
                      
                      function code(v, H)
                      	return atan(-1.0)
                      end
                      
                      function tmp = code(v, H)
                      	tmp = atan(-1.0);
                      end
                      
                      code[v_, H_] := N[ArcTan[-1.0], $MachinePrecision]
                      
                      \begin{array}{l}
                      
                      \\
                      \tan^{-1} -1
                      \end{array}
                      
                      Derivation
                      1. Initial program 66.9%

                        \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
                      2. Add Preprocessing
                      3. Taylor expanded in v around -inf

                        \[\leadsto \tan^{-1} \color{blue}{-1} \]
                      4. Step-by-step derivation
                        1. Applied rewrites36.0%

                          \[\leadsto \tan^{-1} \color{blue}{-1} \]
                        2. Add Preprocessing

                        Reproduce

                        ?
                        herbie shell --seed 2024322 
                        (FPCore (v H)
                          :name "Optimal throwing angle"
                          :precision binary64
                          (atan (/ v (sqrt (- (* v v) (* (* 2.0 9.8) H))))))