Double, approximation of Pi Learn programming Java

Lesson:

Basic Data Types


Exercise:

Double, approximation of Pi 44


Objetive:

Create a program to calculate an approximation for PI using the expression:

pi/4 = 1/1 - 1/3 + 1/5 -1/7 + 1/9 - 1/11 + 1/13 ...

The user will indicate how many terms must be used, and the program will display all the results until that amount of terms.


Code:

import java.util.*;

public class Main
{
	public static void main(String[] args)
	{
		int terms;
		double result = 0;

		System.out.println("PI estimator!");
		System.out.print("Enter the amount of terms to test: ");
		terms = Integer.parseInt(new Scanner(System.in).nextLine());

		for (int i = 1; i <= terms; i++)
		{
			int divisor = 2 * i - 1;
			if (i % 2 == 1)
			{
				result += 1.0f / divisor;
			}
			else
			{
				result -= 1.0f / divisor;
			}

			System.out.printf("To term %1$s: %2$s" + "\r\n", i, 4 * result);
		}
	}
}