/* S0460.java
 *        任意分布乱数の発生 
 *         (C) H.Ishikawa 2008 
 */

package simulation;

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

public class S0460 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();
	}
	
	int SIZE =   10;                /* ヒストグラムの大きさ */
	public void paint(Graphics g){
		Window w ;
		w = new Window();
		int NUMBER  =    10000;

		int j;                          /* forのカウンタ */
		int u;                          /* キザミの番号 */
		int f[] = new int [SIZE];      /* ヒストグラム */
	  
		
		/* グラフィックの準備 */
		int SPACE = 40;
		int HIGHT = 400;
		int WIDTH = 640;
  
		w.setWindow(0,  0.0,0.0,10.0,0.4,  SPACE,HIGHT-SPACE,WIDTH-SPACE,SPACE);
		w.axis(0, "", 1, "", 0.05,g);
	

		/* メイン */
		for (j = 0; j <= NUMBER; j++) {
		    u = (int)(general() * SIZE);
		    if (u >= 0) {f[u] = f[u] + 1;}
		}
				
		/* ヒストグラムを書く */
		g.setColor(Color.red);
		for (u = 0; u < SIZE; u ++)  {
			w.line(0, u+0.5, 0, u+0.5, (double)f[u] / NUMBER, g);
		}
	}
	
	double general()	{
	  double g[]= {0.0,0.02,0.38,0.72,0.85,0.92,0.95,0.97,0.98,0.99,1.0};
	  double x0 = 1.0 / SIZE;
	  double r,x;
	  int i = 0;
	  r = Math.random();
	  while (g[i] < r) {         
	  	i = i + 1;
	  }
	  	x = (r - g[i - 1]) / (g[i] - g[i - 1]) * x0 + (i - 1) * x0;
	  return (x);
	}	
}