kmeans.java

kmeans算法的java实现

                    // 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));
                    // 躡erpr黤ung, ob Position erlaubt ist...
                    if (allowedMousePosition(x,y)==true)
                    {
                        // F黦e 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;			
   }
  /** Zur點ksetzen des Applet durch L鰏chen 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 zuf鋖lig 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 n鋍hsten 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;       
   }
   
}

/** Enth鋖t Informationen der Clusterschwerpunkte, wie Position und Color, aber 
 * auch eine Draw-Methode zum Zeichnen der Schwerpunkte.
 * Au遝rdem werden die Schwerpunkte aus jedem Schleifendurchlauf gespeichert, um
 * den Weg, den die Clusterschwerpunkte von Iteration zu Iteration zur點klegen,
 * darstellen zu k鰊nen.
 */
class Quad {
   static public final int shapeRadius = 12;
   Color color;
   Vector  History;
   int x;
   int y;
   boolean hist;
   
   void draw(Graphics g) {
      if ((hist==true) && (History.size()>0))
      {
          Point p1,p2;
          g.setColor(Color.black);
         for (int i = 0;i<History.size();i++)
          {
              p1 = (Point) History.elementAt(i);
              if (i+1!=History.size())  p2 = (Point) History.elementAt(i+1);
              else
              {
                  p2 = new Point();
                  p2.x = this.x;
                  p2.y = this.y;
              }
              g.drawLine(p1.x+6,p1.y+6,p2.x+6,p2.y+6);
          }
      }
      g.setColor(this.color);
      g.fillOval(this.x, this.y, shapeRadius, shapeRadius);
      g.setColor(Color.black);
      g.drawOval(this.x, this.y, shapeRadius, shapeRadius);
    
    }
}

/** Enth鋖t Informationen der Merkmalsvektoren, sowie eine Methode zum Zeichnen
 * der Vektoren. */
class Cross {
   static public final int shapeRadius = 2;
   Color color;
   int x;
   int y;
   void draw(Graphics g) {
      g.setColor(this.color);
      g.drawLine(this.x - shapeRadius, this.y, this.x + shapeRadius, this.y);
      g.drawLine(this.x, this.y - shapeRadius, this.x, this.y + shapeRadius);
    }
}

/** Repr鋝entiert eine Gausskurve. */
class Gaussian {
   int mux;
   int muy;
   double sigma;
   double function(int x, int y)
   {
       double ret = Math.exp(-0.5*((this.mux-x)*(this.mux-x)+(this.muy-y)*(this.muy-y))/(this.sigma*this.sigma));
       return ret/(Math.sqrt(2*Math.PI)*this.sigma);
   }
  
}