Optimal throwing angle

Percentage Accurate: 67.4% → 99.7%
Time: 12.1s
Alternatives: 5
Speedup: 2.6×

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)))));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(v, h)
use fmin_fmax_functions
    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}

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: 67.4% 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)))));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(v, h)
use fmin_fmax_functions
    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: 99.7% accurate, 0.9× speedup?

\[\begin{array}{l} v\_m = \left|v\right| \\ v\_s = \mathsf{copysign}\left(1, v\right) \\ v\_s \cdot \begin{array}{l} \mathbf{if}\;v\_m \leq 7.5 \cdot 10^{+140}:\\ \;\;\;\;\tan^{-1} \left(\frac{v\_m}{\sqrt{\mathsf{fma}\left(v\_m, v\_m, \left(\left(-9.8\right) - 9.8\right) \cdot H\right)}}\right)\\ \mathbf{else}:\\ \;\;\;\;\tan^{-1} 1\\ \end{array} \end{array} \]
v\_m = (fabs.f64 v)
v\_s = (copysign.f64 #s(literal 1 binary64) v)
(FPCore (v_s v_m H)
 :precision binary64
 (*
  v_s
  (if (<= v_m 7.5e+140)
    (atan (/ v_m (sqrt (fma v_m v_m (* (- (- 9.8) 9.8) H)))))
    (atan 1.0))))
v\_m = fabs(v);
v\_s = copysign(1.0, v);
double code(double v_s, double v_m, double H) {
	double tmp;
	if (v_m <= 7.5e+140) {
		tmp = atan((v_m / sqrt(fma(v_m, v_m, ((-9.8 - 9.8) * H)))));
	} else {
		tmp = atan(1.0);
	}
	return v_s * tmp;
}
v\_m = abs(v)
v\_s = copysign(1.0, v)
function code(v_s, v_m, H)
	tmp = 0.0
	if (v_m <= 7.5e+140)
		tmp = atan(Float64(v_m / sqrt(fma(v_m, v_m, Float64(Float64(Float64(-9.8) - 9.8) * H)))));
	else
		tmp = atan(1.0);
	end
	return Float64(v_s * tmp)
end
v\_m = N[Abs[v], $MachinePrecision]
v\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[v]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[v$95$s_, v$95$m_, H_] := N[(v$95$s * If[LessEqual[v$95$m, 7.5e+140], N[ArcTan[N[(v$95$m / N[Sqrt[N[(v$95$m * v$95$m + N[(N[((-9.8) - 9.8), $MachinePrecision] * H), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[ArcTan[1.0], $MachinePrecision]]), $MachinePrecision]
\begin{array}{l}
v\_m = \left|v\right|
\\
v\_s = \mathsf{copysign}\left(1, v\right)

\\
v\_s \cdot \begin{array}{l}
\mathbf{if}\;v\_m \leq 7.5 \cdot 10^{+140}:\\
\;\;\;\;\tan^{-1} \left(\frac{v\_m}{\sqrt{\mathsf{fma}\left(v\_m, v\_m, \left(\left(-9.8\right) - 9.8\right) \cdot H\right)}}\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if v < 7.4999999999999997e140

    1. Initial program 67.4%

      \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
    2. Applied rewrites67.4%

      \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{\color{blue}{\mathsf{fma}\left(v, v, \left(\left(-9.8\right) - 9.8\right) \cdot H\right)}}}\right) \]

    if 7.4999999999999997e140 < v

    1. Initial program 67.4%

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

      \[\leadsto \tan^{-1} \color{blue}{1} \]
    3. Applied rewrites68.5%

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

Alternative 2: 99.7% accurate, 1.0× speedup?

\[\begin{array}{l} v\_m = \left|v\right| \\ v\_s = \mathsf{copysign}\left(1, v\right) \\ v\_s \cdot \begin{array}{l} \mathbf{if}\;v\_m \leq 7.5 \cdot 10^{+140}:\\ \;\;\;\;\tan^{-1} \left(\frac{v\_m}{\sqrt{v\_m \cdot v\_m - 19.6 \cdot H}}\right)\\ \mathbf{else}:\\ \;\;\;\;\tan^{-1} 1\\ \end{array} \end{array} \]
v\_m = (fabs.f64 v)
v\_s = (copysign.f64 #s(literal 1 binary64) v)
(FPCore (v_s v_m H)
 :precision binary64
 (*
  v_s
  (if (<= v_m 7.5e+140)
    (atan (/ v_m (sqrt (- (* v_m v_m) (* 19.6 H)))))
    (atan 1.0))))
v\_m = fabs(v);
v\_s = copysign(1.0, v);
double code(double v_s, double v_m, double H) {
	double tmp;
	if (v_m <= 7.5e+140) {
		tmp = atan((v_m / sqrt(((v_m * v_m) - (19.6 * H)))));
	} else {
		tmp = atan(1.0);
	}
	return v_s * tmp;
}
v\_m =     private
v\_s =     private
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(v_s, v_m, h)
use fmin_fmax_functions
    real(8), intent (in) :: v_s
    real(8), intent (in) :: v_m
    real(8), intent (in) :: h
    real(8) :: tmp
    if (v_m <= 7.5d+140) then
        tmp = atan((v_m / sqrt(((v_m * v_m) - (19.6d0 * h)))))
    else
        tmp = atan(1.0d0)
    end if
    code = v_s * tmp
end function
v\_m = Math.abs(v);
v\_s = Math.copySign(1.0, v);
public static double code(double v_s, double v_m, double H) {
	double tmp;
	if (v_m <= 7.5e+140) {
		tmp = Math.atan((v_m / Math.sqrt(((v_m * v_m) - (19.6 * H)))));
	} else {
		tmp = Math.atan(1.0);
	}
	return v_s * tmp;
}
v\_m = math.fabs(v)
v\_s = math.copysign(1.0, v)
def code(v_s, v_m, H):
	tmp = 0
	if v_m <= 7.5e+140:
		tmp = math.atan((v_m / math.sqrt(((v_m * v_m) - (19.6 * H)))))
	else:
		tmp = math.atan(1.0)
	return v_s * tmp
v\_m = abs(v)
v\_s = copysign(1.0, v)
function code(v_s, v_m, H)
	tmp = 0.0
	if (v_m <= 7.5e+140)
		tmp = atan(Float64(v_m / sqrt(Float64(Float64(v_m * v_m) - Float64(19.6 * H)))));
	else
		tmp = atan(1.0);
	end
	return Float64(v_s * tmp)
end
v\_m = abs(v);
v\_s = sign(v) * abs(1.0);
function tmp_2 = code(v_s, v_m, H)
	tmp = 0.0;
	if (v_m <= 7.5e+140)
		tmp = atan((v_m / sqrt(((v_m * v_m) - (19.6 * H)))));
	else
		tmp = atan(1.0);
	end
	tmp_2 = v_s * tmp;
end
v\_m = N[Abs[v], $MachinePrecision]
v\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[v]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[v$95$s_, v$95$m_, H_] := N[(v$95$s * If[LessEqual[v$95$m, 7.5e+140], N[ArcTan[N[(v$95$m / N[Sqrt[N[(N[(v$95$m * v$95$m), $MachinePrecision] - N[(19.6 * H), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision], N[ArcTan[1.0], $MachinePrecision]]), $MachinePrecision]
\begin{array}{l}
v\_m = \left|v\right|
\\
v\_s = \mathsf{copysign}\left(1, v\right)

\\
v\_s \cdot \begin{array}{l}
\mathbf{if}\;v\_m \leq 7.5 \cdot 10^{+140}:\\
\;\;\;\;\tan^{-1} \left(\frac{v\_m}{\sqrt{v\_m \cdot v\_m - 19.6 \cdot H}}\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if v < 7.4999999999999997e140

    1. Initial program 67.4%

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

      \[\leadsto \tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \color{blue}{\frac{98}{5} \cdot H}}}\right) \]
    3. Applied rewrites67.4%

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

    if 7.4999999999999997e140 < v

    1. Initial program 67.4%

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

      \[\leadsto \tan^{-1} \color{blue}{1} \]
    3. Applied rewrites68.5%

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

Alternative 3: 95.4% accurate, 0.3× speedup?

\[\begin{array}{l} v\_m = \left|v\right| \\ v\_s = \mathsf{copysign}\left(1, v\right) \\ \begin{array}{l} t_0 := \tan^{-1} \left(\frac{v\_m}{\sqrt{v\_m \cdot v\_m - \left(2 \cdot 9.8\right) \cdot H}}\right)\\ v\_s \cdot \begin{array}{l} \mathbf{if}\;t\_0 \leq 0:\\ \;\;\;\;\tan^{-1} 1\\ \mathbf{elif}\;t\_0 \leq 2 \cdot 10^{-9}:\\ \;\;\;\;\tan^{-1} \left(\sqrt{\frac{-0.05102040816326531}{H}} \cdot v\_m\right)\\ \mathbf{else}:\\ \;\;\;\;\tan^{-1} 1\\ \end{array} \end{array} \end{array} \]
v\_m = (fabs.f64 v)
v\_s = (copysign.f64 #s(literal 1 binary64) v)
(FPCore (v_s v_m H)
 :precision binary64
 (let* ((t_0 (atan (/ v_m (sqrt (- (* v_m v_m) (* (* 2.0 9.8) H)))))))
   (*
    v_s
    (if (<= t_0 0.0)
      (atan 1.0)
      (if (<= t_0 2e-9)
        (atan (* (sqrt (/ -0.05102040816326531 H)) v_m))
        (atan 1.0))))))
v\_m = fabs(v);
v\_s = copysign(1.0, v);
double code(double v_s, double v_m, double H) {
	double t_0 = atan((v_m / sqrt(((v_m * v_m) - ((2.0 * 9.8) * H)))));
	double tmp;
	if (t_0 <= 0.0) {
		tmp = atan(1.0);
	} else if (t_0 <= 2e-9) {
		tmp = atan((sqrt((-0.05102040816326531 / H)) * v_m));
	} else {
		tmp = atan(1.0);
	}
	return v_s * tmp;
}
v\_m =     private
v\_s =     private
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(v_s, v_m, h)
use fmin_fmax_functions
    real(8), intent (in) :: v_s
    real(8), intent (in) :: v_m
    real(8), intent (in) :: h
    real(8) :: t_0
    real(8) :: tmp
    t_0 = atan((v_m / sqrt(((v_m * v_m) - ((2.0d0 * 9.8d0) * h)))))
    if (t_0 <= 0.0d0) then
        tmp = atan(1.0d0)
    else if (t_0 <= 2d-9) then
        tmp = atan((sqrt(((-0.05102040816326531d0) / h)) * v_m))
    else
        tmp = atan(1.0d0)
    end if
    code = v_s * tmp
end function
v\_m = Math.abs(v);
v\_s = Math.copySign(1.0, v);
public static double code(double v_s, double v_m, double H) {
	double t_0 = Math.atan((v_m / Math.sqrt(((v_m * v_m) - ((2.0 * 9.8) * H)))));
	double tmp;
	if (t_0 <= 0.0) {
		tmp = Math.atan(1.0);
	} else if (t_0 <= 2e-9) {
		tmp = Math.atan((Math.sqrt((-0.05102040816326531 / H)) * v_m));
	} else {
		tmp = Math.atan(1.0);
	}
	return v_s * tmp;
}
v\_m = math.fabs(v)
v\_s = math.copysign(1.0, v)
def code(v_s, v_m, H):
	t_0 = math.atan((v_m / math.sqrt(((v_m * v_m) - ((2.0 * 9.8) * H)))))
	tmp = 0
	if t_0 <= 0.0:
		tmp = math.atan(1.0)
	elif t_0 <= 2e-9:
		tmp = math.atan((math.sqrt((-0.05102040816326531 / H)) * v_m))
	else:
		tmp = math.atan(1.0)
	return v_s * tmp
v\_m = abs(v)
v\_s = copysign(1.0, v)
function code(v_s, v_m, H)
	t_0 = atan(Float64(v_m / sqrt(Float64(Float64(v_m * v_m) - Float64(Float64(2.0 * 9.8) * H)))))
	tmp = 0.0
	if (t_0 <= 0.0)
		tmp = atan(1.0);
	elseif (t_0 <= 2e-9)
		tmp = atan(Float64(sqrt(Float64(-0.05102040816326531 / H)) * v_m));
	else
		tmp = atan(1.0);
	end
	return Float64(v_s * tmp)
end
v\_m = abs(v);
v\_s = sign(v) * abs(1.0);
function tmp_2 = code(v_s, v_m, H)
	t_0 = atan((v_m / sqrt(((v_m * v_m) - ((2.0 * 9.8) * H)))));
	tmp = 0.0;
	if (t_0 <= 0.0)
		tmp = atan(1.0);
	elseif (t_0 <= 2e-9)
		tmp = atan((sqrt((-0.05102040816326531 / H)) * v_m));
	else
		tmp = atan(1.0);
	end
	tmp_2 = v_s * tmp;
end
v\_m = N[Abs[v], $MachinePrecision]
v\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[v]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[v$95$s_, v$95$m_, H_] := Block[{t$95$0 = N[ArcTan[N[(v$95$m / N[Sqrt[N[(N[(v$95$m * v$95$m), $MachinePrecision] - N[(N[(2.0 * 9.8), $MachinePrecision] * H), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, N[(v$95$s * If[LessEqual[t$95$0, 0.0], N[ArcTan[1.0], $MachinePrecision], If[LessEqual[t$95$0, 2e-9], N[ArcTan[N[(N[Sqrt[N[(-0.05102040816326531 / H), $MachinePrecision]], $MachinePrecision] * v$95$m), $MachinePrecision]], $MachinePrecision], N[ArcTan[1.0], $MachinePrecision]]]), $MachinePrecision]]
\begin{array}{l}
v\_m = \left|v\right|
\\
v\_s = \mathsf{copysign}\left(1, v\right)

\\
\begin{array}{l}
t_0 := \tan^{-1} \left(\frac{v\_m}{\sqrt{v\_m \cdot v\_m - \left(2 \cdot 9.8\right) \cdot H}}\right)\\
v\_s \cdot \begin{array}{l}
\mathbf{if}\;t\_0 \leq 0:\\
\;\;\;\;\tan^{-1} 1\\

\mathbf{elif}\;t\_0 \leq 2 \cdot 10^{-9}:\\
\;\;\;\;\tan^{-1} \left(\sqrt{\frac{-0.05102040816326531}{H}} \cdot v\_m\right)\\

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


\end{array}
\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (atan.f64 (/.f64 v (sqrt.f64 (-.f64 (*.f64 v v) (*.f64 (*.f64 #s(literal 2 binary64) #s(literal 49/5 binary64)) H))))) < 0.0 or 2.00000000000000012e-9 < (atan.f64 (/.f64 v (sqrt.f64 (-.f64 (*.f64 v v) (*.f64 (*.f64 #s(literal 2 binary64) #s(literal 49/5 binary64)) H)))))

    1. Initial program 67.4%

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

      \[\leadsto \tan^{-1} \color{blue}{1} \]
    3. Applied rewrites68.5%

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

    if 0.0 < (atan.f64 (/.f64 v (sqrt.f64 (-.f64 (*.f64 v v) (*.f64 (*.f64 #s(literal 2 binary64) #s(literal 49/5 binary64)) H))))) < 2.00000000000000012e-9

    1. Initial program 67.4%

      \[\tan^{-1} \left(\frac{v}{\sqrt{v \cdot v - \left(2 \cdot 9.8\right) \cdot H}}\right) \]
    2. Applied rewrites67.4%

      \[\leadsto \tan^{-1} \color{blue}{\left(\sqrt{\frac{1}{v \cdot v - \left(9.8 + 9.8\right) \cdot H}} \cdot v\right)} \]
    3. Taylor expanded in v around 0

      \[\leadsto \tan^{-1} \left(\sqrt{\color{blue}{\frac{\frac{-5}{98}}{H}}} \cdot v\right) \]
    4. Applied rewrites38.4%

      \[\leadsto \tan^{-1} \left(\sqrt{\color{blue}{\frac{-0.05102040816326531}{H}}} \cdot v\right) \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 4: 68.5% accurate, 2.6× speedup?

\[\begin{array}{l} v\_m = \left|v\right| \\ v\_s = \mathsf{copysign}\left(1, v\right) \\ v\_s \cdot \tan^{-1} 1 \end{array} \]
v\_m = (fabs.f64 v)
v\_s = (copysign.f64 #s(literal 1 binary64) v)
(FPCore (v_s v_m H) :precision binary64 (* v_s (atan 1.0)))
v\_m = fabs(v);
v\_s = copysign(1.0, v);
double code(double v_s, double v_m, double H) {
	return v_s * atan(1.0);
}
v\_m =     private
v\_s =     private
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(v_s, v_m, h)
use fmin_fmax_functions
    real(8), intent (in) :: v_s
    real(8), intent (in) :: v_m
    real(8), intent (in) :: h
    code = v_s * atan(1.0d0)
end function
v\_m = Math.abs(v);
v\_s = Math.copySign(1.0, v);
public static double code(double v_s, double v_m, double H) {
	return v_s * Math.atan(1.0);
}
v\_m = math.fabs(v)
v\_s = math.copysign(1.0, v)
def code(v_s, v_m, H):
	return v_s * math.atan(1.0)
v\_m = abs(v)
v\_s = copysign(1.0, v)
function code(v_s, v_m, H)
	return Float64(v_s * atan(1.0))
end
v\_m = abs(v);
v\_s = sign(v) * abs(1.0);
function tmp = code(v_s, v_m, H)
	tmp = v_s * atan(1.0);
end
v\_m = N[Abs[v], $MachinePrecision]
v\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[v]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[v$95$s_, v$95$m_, H_] := N[(v$95$s * N[ArcTan[1.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
v\_m = \left|v\right|
\\
v\_s = \mathsf{copysign}\left(1, v\right)

\\
v\_s \cdot \tan^{-1} 1
\end{array}
Derivation
  1. Initial program 67.4%

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

    \[\leadsto \tan^{-1} \color{blue}{1} \]
  3. Applied rewrites68.5%

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

Alternative 5: 1.8% accurate, 2.6× speedup?

\[\begin{array}{l} v\_m = \left|v\right| \\ v\_s = \mathsf{copysign}\left(1, v\right) \\ v\_s \cdot \tan^{-1} -1 \end{array} \]
v\_m = (fabs.f64 v)
v\_s = (copysign.f64 #s(literal 1 binary64) v)
(FPCore (v_s v_m H) :precision binary64 (* v_s (atan -1.0)))
v\_m = fabs(v);
v\_s = copysign(1.0, v);
double code(double v_s, double v_m, double H) {
	return v_s * atan(-1.0);
}
v\_m =     private
v\_s =     private
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(v_s, v_m, h)
use fmin_fmax_functions
    real(8), intent (in) :: v_s
    real(8), intent (in) :: v_m
    real(8), intent (in) :: h
    code = v_s * atan((-1.0d0))
end function
v\_m = Math.abs(v);
v\_s = Math.copySign(1.0, v);
public static double code(double v_s, double v_m, double H) {
	return v_s * Math.atan(-1.0);
}
v\_m = math.fabs(v)
v\_s = math.copysign(1.0, v)
def code(v_s, v_m, H):
	return v_s * math.atan(-1.0)
v\_m = abs(v)
v\_s = copysign(1.0, v)
function code(v_s, v_m, H)
	return Float64(v_s * atan(-1.0))
end
v\_m = abs(v);
v\_s = sign(v) * abs(1.0);
function tmp = code(v_s, v_m, H)
	tmp = v_s * atan(-1.0);
end
v\_m = N[Abs[v], $MachinePrecision]
v\_s = N[With[{TMP1 = Abs[1.0], TMP2 = Sign[v]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision]
code[v$95$s_, v$95$m_, H_] := N[(v$95$s * N[ArcTan[-1.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
v\_m = \left|v\right|
\\
v\_s = \mathsf{copysign}\left(1, v\right)

\\
v\_s \cdot \tan^{-1} -1
\end{array}
Derivation
  1. Initial program 67.4%

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

    \[\leadsto \tan^{-1} \color{blue}{-1} \]
  3. Applied rewrites1.8%

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

Reproduce

?
herbie shell --seed 2025153 
(FPCore (v H)
  :name "Optimal throwing angle"
  :precision binary64
  (atan (/ v (sqrt (- (* v v) (* (* 2.0 9.8) H))))))