Data.Colour.RGB:hslsv from colour-2.3.3, C

Average Error: 0.03% → 0.03%

Time: 8.2s

Precision: binary64

Cost: 960

Math

\[\frac{x - y}{2 - \left(x + y\right)} \]

↓

\[\begin{array}{l} t_0 := 2 - \left(x + y\right)\\ \frac{x}{t_0} - \frac{y}{t_0} \end{array} \]

FPCore

(FPCore (x y) :precision binary64 (/ (- x y) (- 2.0 (+ x y))))

↓

(FPCore (x y)
 :precision binary64
 (let* ((t_0 (- 2.0 (+ x y)))) (- (/ x t_0) (/ y t_0))))

C

double code(double x, double y) {
	return (x - y) / (2.0 - (x + y));
}

↓

double code(double x, double y) {
	double t_0 = 2.0 - (x + y);
	return (x / t_0) - (y / t_0);
}

Fortran

real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = (x - y) / (2.0d0 - (x + y))
end function

↓

real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    t_0 = 2.0d0 - (x + y)
    code = (x / t_0) - (y / t_0)
end function

Java

public static double code(double x, double y) {
	return (x - y) / (2.0 - (x + y));
}

↓

public static double code(double x, double y) {
	double t_0 = 2.0 - (x + y);
	return (x / t_0) - (y / t_0);
}

Python

def code(x, y):
	return (x - y) / (2.0 - (x + y))

↓

def code(x, y):
	t_0 = 2.0 - (x + y)
	return (x / t_0) - (y / t_0)

Julia

function code(x, y)
	return Float64(Float64(x - y) / Float64(2.0 - Float64(x + y)))
end

↓

function code(x, y)
	t_0 = Float64(2.0 - Float64(x + y))
	return Float64(Float64(x / t_0) - Float64(y / t_0))
end

MATLAB

function tmp = code(x, y)
	tmp = (x - y) / (2.0 - (x + y));
end

↓

function tmp = code(x, y)
	t_0 = 2.0 - (x + y);
	tmp = (x / t_0) - (y / t_0);
end

Wolfram

code[x_, y_] := N[(N[(x - y), $MachinePrecision] / N[(2.0 - N[(x + y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]

↓

code[x_, y_] := Block[{t$95$0 = N[(2.0 - N[(x + y), $MachinePrecision]), $MachinePrecision]}, N[(N[(x / t$95$0), $MachinePrecision] - N[(y / t$95$0), $MachinePrecision]), $MachinePrecision]]

Target

Original	0.03%
Target	0.03%
Herbie	0.03%

\[\frac{x}{2 - \left(x + y\right)} - \frac{y}{2 - \left(x + y\right)} \]

Derivation

1. Initial program 0.03

   \[\frac{x - y}{2 - \left(x + y\right)} \]

2. Simplified 0.03

   \[\leadsto \color{blue}{\frac{x - y}{\left(2 - x\right) - y}} \]
   Proof

   [Start] 0.03	\[ \frac{x - y}{2 - \left(x + y\right)} \]
   associate--r+ [=>] 0.03	\[ \frac{x - y}{\color{blue}{\left(2 - x\right) - y}} \]

3. Applied egg-rr 0.03

   \[\leadsto \color{blue}{\frac{x}{2 - \left(x + y\right)} - \frac{y}{2 - \left(x + y\right)}} \]

4. Final simplification 0.03

   \[\leadsto \frac{x}{2 - \left(x + y\right)} - \frac{y}{2 - \left(x + y\right)} \]

Alternatives

Alternative 1
Error	39.33%
Cost	856

\[\begin{array}{l} \mathbf{if}\;y \leq -5 \cdot 10^{+93}:\\ \;\;\;\;1\\ \mathbf{elif}\;y \leq -9 \cdot 10^{-240}:\\ \;\;\;\;-1\\ \mathbf{elif}\;y \leq -3.4 \cdot 10^{-305}:\\ \;\;\;\;x \cdot 0.5\\ \mathbf{elif}\;y \leq 5 \cdot 10^{-47}:\\ \;\;\;\;-1\\ \mathbf{elif}\;y \leq 0.00037:\\ \;\;\;\;y \cdot -0.5\\ \mathbf{elif}\;y \leq 10^{+82}:\\ \;\;\;\;-1\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]

Alternative 2
Error	26.82%
Cost	848

\[\begin{array}{l} t_0 := \frac{x}{2 - x}\\ \mathbf{if}\;y \leq -4.4 \cdot 10^{+93}:\\ \;\;\;\;1\\ \mathbf{elif}\;y \leq 1.65 \cdot 10^{-47}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;y \leq 0.00037:\\ \;\;\;\;y \cdot -0.5\\ \mathbf{elif}\;y \leq 1.1 \cdot 10^{+82}:\\ \;\;\;\;t_0\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]

Alternative 3
Error	26.77%
Cost	848

\[\begin{array}{l} t_0 := \frac{x}{2 - x}\\ \mathbf{if}\;y \leq -4.1 \cdot 10^{+93}:\\ \;\;\;\;1\\ \mathbf{elif}\;y \leq 8.4 \cdot 10^{-47}:\\ \;\;\;\;t_0\\ \mathbf{elif}\;y \leq 29000:\\ \;\;\;\;\frac{y}{y + -2}\\ \mathbf{elif}\;y \leq 8 \cdot 10^{+81}:\\ \;\;\;\;t_0\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]

Alternative 4
Error	39.18%
Cost	592

\[\begin{array}{l} \mathbf{if}\;y \leq -2 \cdot 10^{+96}:\\ \;\;\;\;1\\ \mathbf{elif}\;y \leq 4.5 \cdot 10^{-47}:\\ \;\;\;\;-1\\ \mathbf{elif}\;y \leq 0.00037:\\ \;\;\;\;y \cdot -0.5\\ \mathbf{elif}\;y \leq 8 \cdot 10^{+81}:\\ \;\;\;\;-1\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]

Alternative 5
Error	0.03%
Cost	576

\[\frac{x - y}{2 - \left(x + y\right)} \]

Alternative 6
Error	38.68%
Cost	328

\[\begin{array}{l} \mathbf{if}\;y \leq -4.1 \cdot 10^{+93}:\\ \;\;\;\;1\\ \mathbf{elif}\;y \leq 9 \cdot 10^{+81}:\\ \;\;\;\;-1\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]

Alternative 7
Error	61.18%
Cost	64

\[-1 \]

Reproduce

herbie shell --seed 2023102 
(FPCore (x y)
  :name "Data.Colour.RGB:hslsv from colour-2.3.3, C"
  :precision binary64

  :herbie-target
  (- (/ x (- 2.0 (+ x y))) (/ y (- 2.0 (+ x y))))

  (/ (- x y) (- 2.0 (+ x y))))