I have this code:

```
package math;
import java.io.IOException;
import java.util.Scanner;
public class Main
{
public static void main(String[] args) throws IOException
{
System.out.println("Hi, I will beat Java's Math.sqrt(double) method");
System.out.println("Both ways of calculation will be done");
System.out.println("I will time how long they took to calculate");
System.out.println("Random doubles will be generated");
System.out.println();
System.out.println("Please give the number of sqrt-calculation will be done");
int calcs = new Scanner(System.in).nextInt();
boolean output = true;
if (calcs > 10000)
{
System.out.println("You're asking much calculations");
System.out.println("Disabling output is recommend");
System.out.println("Disable output? (y/n)");
char a = (char) System.in.read();
if (a == 'y')
{
output = false;
}
}
System.out.println("Press enter to start");
System.in.read();
test(calcs, output);
System.out.println();
System.out.println("I was much faster I think");
System.out.println("Now you can check my precision");
System.out.println("Please give a complex double");
double x = Double.parseDouble(new Scanner(System.in).next());
System.out.println();
System.out.println("Math.sqrt(" + x + ") = " + Math.sqrt(x));
System.out.println("SqrtCalculator.sqrt(" + x + ") = " + sqrt(x));
System.out.println("------------------------");
System.out.println("Now please make your conclusion");
System.out.println("Thanks for trying");
}
public static void test(int calculations, boolean output)
{
double factor = Math.random() / 2;
// Math
long mathStart = System.currentTimeMillis();
for (int i = 1; i <= calculations; i++)
{
double x = i * factor;
double result = Math.sqrt(x);
if (output)
{
System.out.println("Math.sqrt(" + x + ") = " + result);
}
}
long mathStop = System.currentTimeMillis();
long mathTime = mathStop - mathStart;
// My Method
long myStart = System.currentTimeMillis();
for (int i = 1; i <= calculations; i++)
{
double x = i * factor;
double result = sqrt(x);
if (output)
{
System.out.println("SqrtCalculater.sqrt(" + x + ") = " + result);
}
}
long myStop = System.currentTimeMillis();
long myTime = myStop - myStart;
System.out.println();
if (output)
System.out.println("---------------------------");
System.out.println("Here are the results:");
System.out.println("Math and SqrtCalculator did each " + calculations + " of the same sqrt-calculations");
System.out.println();
System.out.println("Math: " + mathTime + " milliseconds");
System.out.println("I: " + myTime + " milliseconds");
}
public final static double sqrt(double x)
{
double previous = 1;
double now = 0;
for (;;)
{
now = (x / previous + previous) / 2;
if (previous == now)
{
return now;
}
previous = now;
}
}
}
```

This sqrt method is called "** heroon**".

If I run my program and I ask 80000 calculations and I disable the output, Math.sqrt() is much faster than my method. If I ask 80000 calcs and I enable the output, My method is much faster.

Can someone explain this?

Thanks

Sorry for bad English.

## Best Solution

I could not reproduce your results. Tried some times using Eclipse Galileo and JDK 1.6.0.

For 80000, output disabled, I got something like:

small times, It would be better to use

`System.nanoTime()`

or more interactions.For 80000, output enabled:

So probably the problem is the way that output is handled (scrolling, buffering, ...)