/* S0530.java
 *       モンテカルロ法による球の体積計算 
 *         (C) H.Ishikawa 2008 
 */

package simulation;

import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import window.Window;

public class S0530 extends Applet implements ActionListener {
	Button button0;
	public void init() {
		button0 = new Button(" 再実行 ");
		add(button0);
		button0.addActionListener(this);
	}
	
	public void actionPerformed(ActionEvent e) {
		String label = e.getActionCommand();
		repaint();
	}

	public void paint(Graphics g){
		Window w ;
		w = new Window();
		int SPACE = 20;
		int HIGHT = 400;
		int WIDTH = 640;
		int NUMBER  =    1000;               /* 乱数の組の数 */
		int    j;                            /* forのカウンタ */
		int    n1 = 0;                       /* 球の中に入った数 */
		double x0, y0, z0;                   /* 点の座標 */
		double v = 0.0;                      /* 体積の近似値 */
	
		w.setWindow(0,  0, 0, NUMBER, 8,  SPACE, HIGHT-SPACE, WIDTH-SPACE, SPACE);
		w.axis(0, "j", NUMBER / 10, "v", 1, g);
		
		g.setColor(Color.green);
		w.moveTo(0, 0.0, 0.0, g);
		for (j = 1; j <= NUMBER; j ++) {
			x0 = Math.random();
			y0 = Math.random();
		    z0 = Math.random();
		    if (x0 * x0 + y0 * y0 + z0 * z0 < 1.0) {  /* 球の中に入った場合 */
		    	n1 = n1 + 1;
		    }
		    v = (double)n1 / j * 8;
		    w.lineTo(0, j, v, g);
		}
		g.setColor(Color.black);
		g.drawString(" v = " + v, 10, 10);
		stop();
	}
}