Estimate Pi by randomly generating points in a 1x1 square and finding fraction of points that fall within a 1/4 circle of radius 1

pi.go

package main

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

func main() {
  converged := false
  inRange := 0
  total := 0
  for !converged {
    // generate random point in a 1x1 square
    x := rand.Float64()
    y := rand.Float64()
    //find distance of point from origin (0,0)
    d := math.Sqrt(x*x + y*y)
    // check to see if random point falls within circle of radius 1
    if d <= 1 {
      inRange++
    }
    total++
    // calculate Pi estimate from area of quarter circle. 4*Area of Quarter circle = Pi
    // if estimaate is within 5 decimal places of actual value stop loop
    if math.Abs(4*float64(inRange)/float64(total) - math.Pi) < 0.00001 {
      converged = true
    }
  }
  piEstimate := 4*float64(inRange)/float64(total)
  fmt.Println(piEstimate)
}