Unbias a random generator: Difference between revisions

=={{header|Go}}==

<lang go>package main

import (

"fmt"

"rand"

)

const samples = 1e6

func main() {

fmt.Println("Generator 1 count 0 count % 1 count")

for n := 3; n <= 6; n++ {

// function randN, per task description

randN := func() int {

if rand.Intn(n) == 0 {

return 1

}

return 0

}

var b [2]int

for x := 0; x < samples; x++ {

b[randN()]++

}

fmt.Printf("randN(%d) %7d %7d %5.2f%%\n",

n, b[1], b[0], float64(b[1])*100/samples)

// function unbiased, per task description

unbiased := func() (b int) {

for b = randN(); b == randN(); b = randN() {

}

return

}

var u [2]int

for x := 0; x < samples; x++ {

u[unbiased()]++

}

fmt.Printf("unbiased %7d %7d %5.2f%%\n",

u[1], u[0], float64(u[1])*100/samples)

}

}</lang>

Output:

<pre>

Generator 1 count 0 count % 1 count

randN(3) 332711 667289 33.27%

unbiased 499649 500351 49.96%

randN(4) 249742 750258 24.97%

unbiased 499434 500566 49.94%

randN(5) 200318 799682 20.03%

unbiased 499100 500900 49.91%

randN(6) 166900 833100 16.69%

unbiased 499973 500027 50.00%

</pre>