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 | package systeme;
import java.applet.Applet;
import java.util.*;
import java.awt.*;
 
/**
 * Dieses Applet implementiert das k-means Verfahren. Dieses ist ein unüberwachtes
 * Klassifikationsverfahren (auch Clustering Verfahren genannt), mit dem sich 
 * Merkmalsvektoren im Merkmalsraum in Ballungszentren bzw. Cluster aufteilen 
 * lassen. 
 * 
 * @author Jens Spehr
 *
 */
 
public class Kmeans extends Applet implements Runnable {
   Vector  CrossList; /** Enthält alle Merkmalsvektoren */
   Vector  Centroids; /** Enthält die Schwerpunkte der Cluster */
   Choice  SubsetChoice; /** Steuerelement */
   Button StartButton,RestartButton,ResetButton,RunButton,DrawGButton; /** Buttons*/
   Checkbox history; /** Checkbox */
 
   Thread Go;  /** Thread für den Run-Modus. */
   int step;   /** Aktueller Schritt, in dem sich der Algorithmus befindet. */
   int subset; /** Anzahl der Cluster */ 
   Random rand; /** Zufallsvariable*/
   boolean abort; /** Abbruchkriterium */
 
   /** Erstellt das Graphic User Interface (GUI). */
   public void init() {
      rand = new Random();
      Centroids = new Vector();
 
      StartButton = new Button("Start");
      add(StartButton);
      StartButton.setEnabled(false);
 
      RestartButton = new Button("New Start");
      add(RestartButton);
      RestartButton.setEnabled(false);
 
      ResetButton = new Button("Reset");
      add(ResetButton);
      ResetButton.setEnabled(false);
 
      RunButton = new Button("Run");
      add(RunButton);
      RunButton.setEnabled(false);
 
      DrawGButton = new Button("Draw Cluster");
      add(DrawGButton);
 
      CrossList = new Vector();
 
      SubsetChoice = new Choice();
      SubsetChoice.addItem("2");
      SubsetChoice.addItem("3");
      SubsetChoice.addItem("4");
      SubsetChoice.addItem("5");
      SubsetChoice.addItem("6");
      SubsetChoice.addItem("7");
      SubsetChoice.addItem("8");
      add(SubsetChoice);
 
      history = new Checkbox("Show History");
      add(history);
 
      subset = 2;
      step = -1;
   }
 
 
   /** Zeichnet den Text, die Merkmalsvektoren und die Clusterschwerpunkte. */
   public void paint(Graphics g) 
   {
        g.setColor(Color.BLACK);
        g.drawRect(0, 500, 499, 300); 
 
        StringBuffer buffer;
        if (step == 1)    g.setColor(Color.red);
        else g.setColor(Color.black);
	buffer = new StringBuffer("Step 1: Place ranomly initial group centroids into the 2d space.");	
	g.drawString(buffer.toString(),2, 370);
 
         if (step == 2)     g.setColor(Color.red);
        else g.setColor(Color.black);
	buffer = new StringBuffer("Step 2: Assign each object to the group that has the closest centroid.");	
	g.drawString(buffer.toString(),2, 385);
 
         if (step == 3)     g.setColor(Color.red);
        else g.setColor(Color.black);
	buffer = new StringBuffer("Step 3: Recalculate the positions of the centroids. ");	
	g.drawString(buffer.toString(),2, 400);
 
        if (step == 4)     g.setColor(Color.red);
        else g.setColor(Color.black);
	buffer = new StringBuffer("Step 4: If the positions of the centroids didn't change go to the next step, else go to Step 2.");	
	g.drawString(buffer.toString(),2, 415);
 
        if (step == 5)     g.setColor(Color.red);
        else g.setColor(Color.black);
	buffer = new StringBuffer("Step 5: End.");	
	g.drawString(buffer.toString(),2, 430);
 
        // Zeichnet die Merkmalsvektoren
        Cross s;
        int numShapes = CrossList.size();
        for (int i = 0; i < numShapes; i++) 
        {
            s = (Cross) CrossList.elementAt(i); 
            s.draw(g);  
        }
        // Zeichnet die Clusterschwerpunkte
        if (step != -1) 
        {
            Quad t = new Quad();
            int numCent = Centroids.size();
            for (int i = 0; i < numCent; i++) 
            {
                t = (Quad) Centroids.elementAt(i);
                t.hist = history.getState();
 
                t.draw(g);  
            }
        }
 
   }
 
   /** Erzeugt einen neuen Merkmalsvektor durch einen Mausklick. */
   public boolean mouseUp(Event e, int x, int y) {
 
      if ((step == -1) && (allowedMousePosition(x,y)== true))
      {
          ResetButton.setEnabled(true);
          StartButton.setEnabled(true);
          RunButton.setEnabled(true);
 
          Cross s = new Cross();  
 
          s.color = Color.black;
          s.x = x;
          s.y = y;
          CrossList.addElement(s);
 
          repaint();
      }
 
      return true;
   }
 
   /** Überprüfung, ob die aktuelle Mausposition erlaubt ist. */
   public boolean allowedMousePosition(int x, int y)
   {
       if ((x>=5)&&(y>=55)&&(x<595)&&(y<345)) return true;
       else return false;
   }
 
   /** Automatisches Durchlaufen des k-means Verfahrens. In einem Schritt wird
    * für ca. 100ms verweilt. */
   public void run() {
	while (true) {
                if      (step ==-1) this.step1();
                else if (step == 1) this.step2();
                else if (step == 2) this.step3();
                else if (step == 3) step = 4;
                else if ((step == 4) && (abort==true))
                {
                    RestartButton.setEnabled(true);
                    ResetButton.setEnabled(true);
                    step = 5;
                    repaint();
                    Go.stop();
                }
                else if ((step == 4) && (abort==false))    this.step2();   
                repaint();
		try {			// Thread erfordert Ausnahme-Handler (try-catch-Klausel)
		Thread.sleep(100);
		}
		catch (InterruptedException e) {
		}
	}
}
 
   /** Managen der Button Ereignisse. */
   public boolean action(Event event, Object eventobject)
   {				
        if ((event.target==StartButton))
        {
            StartButton.setLabel("Step");
            RestartButton.setEnabled(true);
            if      (step ==-1) this.step1();
            else if (step == 1) this.step2();
            else if (step == 2) this.step3();
            else if (step == 3) step = 4;
            else if ((step == 4) && (abort==true))
            {
                StartButton.setEnabled(false);
                RunButton.setEnabled(false);
                step = 5;
            }
            else if ((step == 4) && (abort==false))    this.step2();   
            repaint();
            return true; 
        } 
         if ((event.target==RunButton))
        {
 
            Go = new Thread(this);
            Go.start();
            StartButton.setEnabled(false);
            RestartButton.setEnabled(false);
            ResetButton.setEnabled(false);
            RunButton.setEnabled(false);
 
            return true; 
        } 
        if ((event.target==DrawGButton))
        {
            if (CrossList.size()>0)  Reset();
 
            String SubsetString = SubsetChoice.getSelectedItem();
            if (SubsetString.equals("2")) subset = 2;
            if (SubsetString.equals("3")) subset = 3;
            if (SubsetString.equals("4")) subset = 4;
            if (SubsetString.equals("5")) subset = 5;
            if (SubsetString.equals("6")) subset = 6;
            if (SubsetString.equals("7")) subset = 7;
            if (SubsetString.equals("8")) subset = 8;
 
            // Erstelle Gausverteilungen
            Vector  GaussianList;
            GaussianList = new Vector();
            for (int i = 0; i<subset;i++)
            {
                Gaussian gaus = new Gaussian();  
                // Initialisiere Erwartungswert
                gaus.mux = 50 + Math.abs(rand.nextInt() % 450);
                gaus.muy = 75 + Math.abs(rand.nextInt() % 275);
                // Initialisiere Standardabweichung
                gaus.sigma = 10 + Math.abs(30 * rand.nextDouble());
 
                GaussianList.addElement(gaus);
            }
            ResetButton.setEnabled(true);
            StartButton.setEnabled(true);
            RunButton.setEnabled(true);
 
            // Erzeuge die Merkmalsvektoren
            for (int i = 0; i<subset;i++)
            {
                // Wähle Gausverteilung
                Gaussian gaus;
                gaus = (Gaussian) GaussianList.elementAt(i);
                // Erzeuge die Merkmalsvektoren für das ausgewählte Cluster
                for (int j = 0;j<2800/subset;j++)
                {
                    // Zur Performance-Steigerung wird hier keine "echte"
                    // Gausskurve verwendet. 
                    double r = 5*gaus.sigma*Math.pow(rand.nextDouble(),2);
                    double alpha = 2*Math.PI*rand.nextDouble();
                    int x = gaus.mux + (int) Math.round(r*Math.cos(alpha));
                    int y = gaus.muy + (int) Math.round(r*Math.sin(alpha));
                    // Überprüfung, ob Position erlaubt ist...
                    if (allowedMousePosition(x,y)==true)
                    {
                        // Füge den Merkmalvektor der CrossList hinzu.
                        Cross s = new Cross();  
                        s.color = Color.black;
                        s.x = x;
                        s.y = y;
                        CrossList.addElement(s);
                    }
                  }
            }
 
            repaint();
            return true; 
        } 
 
         if ((event.target==RestartButton)  && (step !=-1))
        {
            step = -1;
            abort = false;
            Centroids.removeAllElements();
            int numShapes = CrossList.size();
            Cross s;
            for (int i = 0; i < numShapes; i++) 
            {
                   s = (Cross) CrossList.elementAt(i); 
                   s.color = Color.black;
            }
            StartButton.setLabel("Start");
            StartButton.setEnabled(true);
            ResetButton.setEnabled(true);
            RunButton.setEnabled(true);
 
            this.repaint(); 
            return true; 
        } 
         if ((event.target==ResetButton))
        {
           Reset();
           return true; 
        } 
        return true;			
   }
  /** Zurücksetzen des Applet durch Löschen von allen Merkmalsvektoren und 
   * Clusterschwerpunkten. */
  public void Reset()
  {
    step = -1;
    abort = false;
    Centroids.removeAllElements();
    int numShapes = CrossList.size();
    Cross s;
    for (int i = 0; i < numShapes; i++) 
    {
           s = (Cross) CrossList.elementAt(i); 
           s.color = Color.white;
    }
    StartButton.setLabel("Start");
    StartButton.setEnabled(false);
    RestartButton.setEnabled(false);
    ResetButton.setEnabled(false);
    RunButton.setEnabled(false);
    CrossList.removeAllElements();
 
    this.repaint();  
  }
 
 /** Verteilt zufällig die Clusterschwerpunkte im 2d Merkmalsraum. */
   public void step1()
   {
       abort = false;
       String SubsetString = SubsetChoice.getSelectedItem();
       if (SubsetString.equals("2")) subset = 2;
       if (SubsetString.equals("3")) subset = 3;
       if (SubsetString.equals("4")) subset = 4;
       if (SubsetString.equals("5")) subset = 5;
       if (SubsetString.equals("6")) subset = 6;
       if (SubsetString.equals("7")) subset = 7;
       if (SubsetString.equals("8")) subset = 8;
       int numShapes = CrossList.size();
       boolean ch[] = new boolean[numShapes];
       for (int i = 0; i<numShapes;i++) ch[i]=false;
       for (int i = 0; i<subset;)
       {
           Cross s;
           Quad p = new Quad();
           int r = Math.abs(rand.nextInt() % numShapes);
           if (ch[r]==false)
           {
               s = (Cross) CrossList.elementAt(r); 
               p.x = s.x;
               p.y = s.y;
               if (i == 0) p.color = Color.green;
               else if (i == 1) p.color = Color.red;
               else if (i == 2) p.color = Color.blue;
               else if (i == 3) p.color = Color.yellow;
               else if (i == 4) p.color = Color.orange;
               else if (i == 5) p.color = Color.magenta;
               else if (i == 6) p.color = Color.cyan;
               else if (i == 7) p.color = Color.lightGray;
               else if (i == 8) p.color = Color.darkGray;
               p.History = new Vector();
 
               Centroids.addElement(p);
               ch[r] = true;
               i++;
           }
        }
       step = 1;  
   }
 
   /** Zuordnung von jedem Merkmalsvektore zum jeweils nächsten Clusterschwerpunkt */
   public void step2()
   {
        Cross s;
        Quad p;
        int numShapes = CrossList.size();
        for (int i = 0; i < numShapes; i++) 
        {
            s = (Cross) CrossList.elementAt(i); 
 
            int numCent = Centroids.size();
            int min = 0;
            double dist_min = 99999999.9;
            for (int j = 0; j < numCent; j++) 
            {
                p = (Quad) Centroids.elementAt(j);
 
                double dist = Point.distance(s.x, s.y, p.x, p.y);
                if (dist < dist_min) 
                {
                    dist_min = dist;
                    min = j;
                }
            }
            p = (Quad) Centroids.elementAt(min);
            s.color = p.color;
        }
        step = 2;
   }
 
   /** Neuberechnung der Clusterschwerpunkte. */
   public void step3()
   {
        Quad p;
        Cross s;
        Point m = new Point();
        double changes = 0.0;
        int numCent = Centroids.size();
        for (int j = 0; j < numCent; j++) 
        {
           p = (Quad) Centroids.elementAt(j);
           m.x = 0;
           m.y = 0;
           int Count = 0;
           int numShapes = CrossList.size();
           for (int i = 0; i < numShapes; i++) 
           {
               s = (Cross) CrossList.elementAt(i); 
               if (s.color == p.color) 
               {
                   m.x += s.x;
                   m.y += s.y;
                   Count++;
               }
           }
           if (Count>0)
           {
               changes += Point.distance(p.x,p.y,m.x/Count, m.y/Count);
               Point pt = new Point();
               pt.x = p.x;
               pt.y = p.y;
               p.History.addElement(pt);
               p.x = m.x / Count;
               p.y = m.y / Count;
           }
        }   
       if (changes<0.1)  abort = true;
       step = 3;       
   }
 
} |