import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.util.*;


public class Applet1 extends Applet {

  double datax[]=new double[50];
  double datay[]=new double[50];
  int dsx=0;
  double minx,fmin;
  double maxx,fmax;

  private TextField dataField = new TextField();
  private Button mapbutton = new Button();
  //引数値の取得
  public String getParameter(String key, String def) {
    return isStandalone ? System.getProperty(key, def) :
      (getParameter(key) != null ? getParameter(key) : def);
  }

  //アプレットのビルド
  public Applet1() {
  }
  //アプレットの初期化
  public void init() {
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
    SetData();
    recursion();
  }
  //コンポーネントの初期化
  private void jbInit() throws Exception {
    dataField.setText("32.1,34.4,36.2,41.1,39.5,38.6,45.5,44.0,48.9,52.9,53.8,52.4");
    dataField.setBounds(new Rectangle(30, 238, 339, 21));
    this.setLayout(null);
    mapbutton.setLabel("再計算");
    mapbutton.setBounds(new Rectangle(34, 272, 81, 19));
    mapbutton.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        mapbutton_actionPerformed(e);
      }
    });
    this.add(dataField, null);
    this.add(mapbutton, null);
  }

  void mapbutton_actionPerformed(ActionEvent e) {
    //再描画
    SetData();
    recursion();
    repaint();
  }

  void SetData(){
    //データを読む
    dsx=0;
    String st=dataField.getText();
    StringTokenizer tkn=new StringTokenizer(st,",");
    while(tkn.hasMoreTokens()){
      datax[dsx]=Double.parseDouble(tkn.nextToken());
      datay[dsx++]=Double.parseDouble(tkn.nextToken());
    }
  }

 public void paint(Graphics g){
   int osx=20,osy=220;
   int wd=200,ht=200;
//軸を表示
   g.drawLine(osx,osy,osx+wd,osy);
   g.drawLine(osx,osy,osx,osy-ht);
//散布図を表示
   for(int i=0;i<dsx;i++){
     g.drawRect(fx(datax[i])+osx-2,osy-fy(datay[i])-2,5,5);
     g.drawLine(fx(datax[i])+osx,osy-fy(datay[i]),
                fx(datax[i])+osx,osy-fy(datay[i]));
   }
   //回帰直線の表示
   g.drawLine(fx(minx)+osx,osy-fy(fmin),
       fx(maxx)+osx,osy-fy(fmax));
 }

//x座標の変換
 int fx(double x){
   double sx=5.0;
   double bx=30;
   return (int)((x-bx)*sx);
 }

//y座標の変換
 int fy(double y){
   double sy=5.0;
   double by=30;
   return (int)((y-by)*sy);
 }

//回帰直線を求める
 void recursion(){
   double sx=0.0,sy=0.0,sxy=0.0,sx2=0.0;
   double bc,ac;

//回帰直線の計数の計算、　x座標の最小、最大を求める
   minx=datax[0];
   maxx=datax[0];
   for(int i=0;i<dsx;i++){
     sx += datax[i];
     sx2 += datax[i]*datax[i];
     sy += datay[i];
     sxy += datax[i]*datay[i];
     if(minx>datax[i]) minx=datax[i];
     if(maxx<datax[i]) maxx=datax[i];
   }

//回帰直線　y = ac + bc(x-E(x)) E(x)はxの平均
   ac=sy/dsx;
   bc=(sxy-sx*sy/dsx)/(sx2-sx*sx/dsx);
   //System.out.println("a:"+ac+" b:"+bc);
   fmin=ac+bc*(minx-sx/dsx);
   fmax=ac+bc*(maxx-sx/dsx);
   //System.out.println("minx:"+minx+" fmin:"+fmin);
 }

}//class