Codec.Picture.Types:toneMapping from JuicyPixels-3.2.6.1

Average Error: 9.0 → 0.1

Time: 17.6s

Precision: binary64

Cost: 968

Math

\[\frac{x \cdot \left(\frac{x}{y} + 1\right)}{x + 1} \]

↓

\[\begin{array}{l} t_0 := \left(1 + \frac{x}{y}\right) - \frac{1}{y}\\ \mathbf{if}\;x \leq -4 \cdot 10^{+37}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;x \leq 10^{+15}:\\ \;\;\;\;\frac{x \cdot \left(\frac{x}{y} + 1\right)}{x + 1}\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \]

FPCore

(FPCore (x y) :precision binary64 (/ (* x (+ (/ x y) 1.0)) (+ x 1.0)))

↓

(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- (+ 1.0 (/ x y)) (/ 1.0 y))))
   (if (<= x -4e+37)
     t_0
     (if (<= x 1e+15) (/ (* x (+ (/ x y) 1.0)) (+ x 1.0)) t_0))))

C

double code(double x, double y) {
	return (x * ((x / y) + 1.0)) / (x + 1.0);
}

↓

double code(double x, double y) {
	double t_0 = (1.0 + (x / y)) - (1.0 / y);
	double tmp;
	if (x <= -4e+37) {
		tmp = t_0;
	} else if (x <= 1e+15) {
		tmp = (x * ((x / y) + 1.0)) / (x + 1.0);
	} else {
		tmp = t_0;
	}
	return tmp;
}

Fortran

real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = (x * ((x / y) + 1.0d0)) / (x + 1.0d0)
end function

↓

real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (1.0d0 + (x / y)) - (1.0d0 / y)
    if (x <= (-4d+37)) then
        tmp = t_0
    else if (x <= 1d+15) then
        tmp = (x * ((x / y) + 1.0d0)) / (x + 1.0d0)
    else
        tmp = t_0
    end if
    code = tmp
end function

Java

public static double code(double x, double y) {
	return (x * ((x / y) + 1.0)) / (x + 1.0);
}

↓

public static double code(double x, double y) {
	double t_0 = (1.0 + (x / y)) - (1.0 / y);
	double tmp;
	if (x <= -4e+37) {
		tmp = t_0;
	} else if (x <= 1e+15) {
		tmp = (x * ((x / y) + 1.0)) / (x + 1.0);
	} else {
		tmp = t_0;
	}
	return tmp;
}

Python

def code(x, y):
	return (x * ((x / y) + 1.0)) / (x + 1.0)

↓

def code(x, y):
	t_0 = (1.0 + (x / y)) - (1.0 / y)
	tmp = 0
	if x <= -4e+37:
		tmp = t_0
	elif x <= 1e+15:
		tmp = (x * ((x / y) + 1.0)) / (x + 1.0)
	else:
		tmp = t_0
	return tmp

Julia

function code(x, y)
	return Float64(Float64(x * Float64(Float64(x / y) + 1.0)) / Float64(x + 1.0))
end

↓

function code(x, y)
	t_0 = Float64(Float64(1.0 + Float64(x / y)) - Float64(1.0 / y))
	tmp = 0.0
	if (x <= -4e+37)
		tmp = t_0;
	elseif (x <= 1e+15)
		tmp = Float64(Float64(x * Float64(Float64(x / y) + 1.0)) / Float64(x + 1.0));
	else
		tmp = t_0;
	end
	return tmp
end

MATLAB

function tmp = code(x, y)
	tmp = (x * ((x / y) + 1.0)) / (x + 1.0);
end

↓

function tmp_2 = code(x, y)
	t_0 = (1.0 + (x / y)) - (1.0 / y);
	tmp = 0.0;
	if (x <= -4e+37)
		tmp = t_0;
	elseif (x <= 1e+15)
		tmp = (x * ((x / y) + 1.0)) / (x + 1.0);
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end

Wolfram

code[x_, y_] := N[(N[(x * N[(N[(x / y), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision] / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]

↓

code[x_, y_] := Block[{t$95$0 = N[(N[(1.0 + N[(x / y), $MachinePrecision]), $MachinePrecision] - N[(1.0 / y), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[x, -4e+37], t$95$0, If[LessEqual[x, 1e+15], N[(N[(x * N[(N[(x / y), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision] / N[(x + 1.0), $MachinePrecision]), $MachinePrecision], t$95$0]]]

Target

Original	9.0
Target	0.1
Herbie	0.1

\[\frac{x}{1} \cdot \frac{\frac{x}{y} + 1}{x + 1} \]

Derivation

1. Split input into 2 regimes

2. if x < -3.99999999999999982e37 or 1e15 < x

   1. Initial program 22.9

      \[\frac{x \cdot \left(\frac{x}{y} + 1\right)}{x + 1} \]

   2. Taylor expanded in x around inf 0.0

      \[\leadsto \color{blue}{\left(1 + \frac{x}{y}\right) - \frac{1}{y}} \]

   if -3.99999999999999982e37 < x < 1e15

   1. Initial program 0.2

      \[\frac{x \cdot \left(\frac{x}{y} + 1\right)}{x + 1} \]
3. Recombined 2 regimes into one program.

4. Final simplification 0.1

   \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq -4 \cdot 10^{+37}:\\ \;\;\;\;\left(1 + \frac{x}{y}\right) - \frac{1}{y}\\ \mathbf{elif}\;x \leq 10^{+15}:\\ \;\;\;\;\frac{x \cdot \left(\frac{x}{y} + 1\right)}{x + 1}\\ \mathbf{else}:\\ \;\;\;\;\left(1 + \frac{x}{y}\right) - \frac{1}{y}\\ \end{array} \]

Alternatives

Alternative 1
Error	20.3
Cost	848

\[\begin{array}{l} t_0 := 1 - \frac{1}{y}\\ \mathbf{if}\;x \leq -1.1 \cdot 10^{+93}:\\ \;\;\;\;\frac{x}{y}\\ \mathbf{elif}\;x \leq -1:\\ \;\;\;\;t_0\\ \mathbf{elif}\;x \leq 95000:\\ \;\;\;\;x\\ \mathbf{elif}\;x \leq 2.35 \cdot 10^{+55}:\\ \;\;\;\;t_0\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{y}\\ \end{array} \]

Alternative 2
Error	9.9
Cost	840

\[\begin{array}{l} t_0 := \left(1 + \frac{x}{y}\right) - \frac{1}{y}\\ \mathbf{if}\;x \leq -80000000000:\\ \;\;\;\;t_0\\ \mathbf{elif}\;x \leq 3000:\\ \;\;\;\;\frac{x}{x + 1}\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \]

Alternative 3
Error	19.6
Cost	584

\[\begin{array}{l} \mathbf{if}\;x \leq -1.55 \cdot 10^{+92}:\\ \;\;\;\;\frac{x}{y}\\ \mathbf{elif}\;x \leq 1.4 \cdot 10^{+54}:\\ \;\;\;\;\frac{x}{x + 1}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{y}\\ \end{array} \]

Alternative 4
Error	19.5
Cost	456

\[\begin{array}{l} \mathbf{if}\;x \leq -1:\\ \;\;\;\;\frac{x}{y}\\ \mathbf{elif}\;x \leq 0.102:\\ \;\;\;\;x\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{y}\\ \end{array} \]

Alternative 5
Error	36.6
Cost	64

\[x \]

Reproduce

herbie shell --seed 2023077 
(FPCore (x y)
  :name "Codec.Picture.Types:toneMapping from JuicyPixels-3.2.6.1"
  :precision binary64

  :herbie-target
  (* (/ x 1.0) (/ (+ (/ x y) 1.0) (+ x 1.0)))

  (/ (* x (+ (/ x y) 1.0)) (+ x 1.0)))