Statistical method for determine the value of Pi in Ruby and Go

pi.go

package main

import (
    "fmt"
    "math"
    "math/rand"
    "time"
)

var pi, dev float64

func stones(N int) (float64, float64) {
  var x, y, point, Nc, Ns, sum, mu, V float64

  for i := 0; i < N; i++ {
    x = 2.0 * rand.Float64() - 1.0
    y = 2.0 * rand.Float64() - 1.0

    point = x * x + y * y

    if point < 1.0 {
      Nc += 1
    } else {
      Ns += 1
    }
  }

  pi = 4.0 * Nc / (Nc + Ns)

  sum += pi

  mu = sum/(Nc + Ns)

  V = (math.Pow( (mu - pi), 2))/(Nc + Ns)

  dev = math.Pow(V, 0.5)

  return pi, dev
}

func main() {
  var count int

  rand.Seed(time.Now().UTC().UnixNano())

  for i := 1; i <= 100; i += 1 {
    count = i * 1000
    pi, dev = stones(count)
    fmt.Printf("%d\t%f10\t%f10\n", count, pi, dev)
  }
}

pi.rb

def stones iterations
  r = Random.new(Time.now.utc.usec)

  nc = 0.0

  iterations.times do
    x = 2.0 * r.rand - 1.0
    y = 2.0 * r.rand - 1.0

    point = x * x + y * y

    nc += 1 if point < 1.0
  end

  pi = 4.0 * nc / iterations

  mu = pi / iterations

  sigma = ((pi - mu) ** 2) / iterations

  dev = sigma ** 0.5

  return pi, dev
end

101.times do |i|
  count = i * 1000

  pi, dev = stones(count)

  printf("%d\t%f10\t%f10\n", count, pi, dev)
end