Data.Colour.CIE:cieLAB from colour-2.3.3, D

Average Error: 0.01% → 0.01%

Time: 2.7s

Precision: binary64

Cost: 320

Math

\[x - \frac{y}{200} \]

↓

\[x - \frac{y}{200} \]

FPCore

(FPCore (x y) :precision binary64 (- x (/ y 200.0)))

↓

(FPCore (x y) :precision binary64 (- x (/ y 200.0)))

C

double code(double x, double y) {
	return x - (y / 200.0);
}

↓

double code(double x, double y) {
	return x - (y / 200.0);
}

Fortran

real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = x - (y / 200.0d0)
end function

↓

real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    code = x - (y / 200.0d0)
end function

Java

public static double code(double x, double y) {
	return x - (y / 200.0);
}

↓

public static double code(double x, double y) {
	return x - (y / 200.0);
}

Python

def code(x, y):
	return x - (y / 200.0)

↓

def code(x, y):
	return x - (y / 200.0)

Julia

function code(x, y)
	return Float64(x - Float64(y / 200.0))
end

↓

function code(x, y)
	return Float64(x - Float64(y / 200.0))
end

MATLAB

function tmp = code(x, y)
	tmp = x - (y / 200.0);
end

↓

function tmp = code(x, y)
	tmp = x - (y / 200.0);
end

Wolfram

code[x_, y_] := N[(x - N[(y / 200.0), $MachinePrecision]), $MachinePrecision]

↓

code[x_, y_] := N[(x - N[(y / 200.0), $MachinePrecision]), $MachinePrecision]

Derivation

1. Initial program 0.01

   \[x - \frac{y}{200} \]

2. Final simplification 0.01

   \[\leadsto x - \frac{y}{200} \]

Alternatives

Alternative 1
Error	26.27%
Cost	457

\[\begin{array}{l} \mathbf{if}\;y \leq -1.08 \cdot 10^{-51} \lor \neg \left(y \leq 1.45 \cdot 10^{-37}\right):\\ \;\;\;\;y \cdot -0.005\\ \mathbf{else}:\\ \;\;\;\;x\\ \end{array} \]

Alternative 2
Error	0.1%
Cost	320

\[x + y \cdot -0.005 \]

Alternative 3
Error	47.98%
Cost	64

\[x \]

Reproduce

herbie shell --seed 2023102 
(FPCore (x y)
  :name "Data.Colour.CIE:cieLAB from colour-2.3.3, D"
  :precision binary64
  (- x (/ y 200.0)))