Efficient Implementation of Newtons Formula for Square Roots

newton.go

package main

import (
	"fmt"
	"math"
	)

func Sqrt(x float64) float64 {
	digits := math.Floor( math.Log10( x ) ) + 1
	guess := x/math.Pow(10,digits/2)
	fmt.Println("Start Guess: ",guess)
	y := 0.0
	i := 0
	for math.Abs(guess-y) > math.Pow(10,-3) {
		i++
		y = guess
		guess = guess - (math.Pow(guess,2) - x) / (2.0*guess)
	}
	fmt.Println(i)
	return guess
}

func main() {
	x := 1252460.0
	guess := Sqrt(x)
	fmt.Println(guess)
	real := math.Sqrt(x)
	fmt.Println(real)
	diff := real - guess
	fmt.Println(diff)
}