psodemo.java

A program to demonstrate the optimization process of particle swarm optimization. A two-dimensional

  public void saveImage (File file)
  {                             /* --- save image to a file */
    FileOutputStream stream;    /* stream to write to */

    if (file == null) {         /* if no file name is given */
      if (this.chooser == null) this.chooser = this.createChooser();
      this.chooser.setDialogType(JFileChooser.SAVE_DIALOG);
      int r = this.chooser.showDialog(this, null);
      if (r != JFileChooser.APPROVE_OPTION) return;
      file = this.chooser.getSelectedFile();
    }                           /* let the user choose a file name */
    try {                       /* save the decision tree image */
      ImageIO.write(this.panel.makeImage(), "png",
                  new FileOutputStream(file)); }
    catch (java.io.IOException ioe) {
      String msg = "file " +file.getName() +":\n" +ioe.getMessage();
      stat.setText(msg); System.err.println(msg);
      JOptionPane.showMessageDialog(this, msg, "alert",
        JOptionPane.ERROR_MESSAGE);
    }                           /* set the status text */
  }  /* saveImage() */

  /*------------------------------------------------------------------*/

  private JDialog createFnSel ()
  {                             /* --- create "Select..." dialog */
    final JDialog      dlg  = new JDialog(this, "Select Function...");
    GridBagLayout      g    = new GridBagLayout();
    GridBagConstraints lc   = new GridBagConstraints();
    GridBagConstraints rc   = new GridBagConstraints();
    JPanel             grid = new JPanel(g);
    JPanel             bbar;
    JLabel             lbl;
    JTextArea          help;
    JButton            btn;

    grid.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
    lc.fill      =              /* fill fields in both directions */
    rc.fill      = GridBagConstraints.BOTH;
    rc.weightx   = 1.0;         /* resize only the input fields, */
    lc.weightx   = 0.0;         /* but not the labels */
    lc.weighty   = 0.0;         /* resize lines equally */
    rc.weighty   = 0.0;         /* in vertical direction */
    lc.ipadx     = 10;          /* gap between labels and inputs */
    lc.ipady     = 10;          /* make all lines of the same height */
    rc.gridwidth = GridBagConstraints.REMAINDER;

    lbl = new JLabel("Function to optimize:");
    g.setConstraints(lbl, lc);    grid.add(lbl);
    final JComboBox selfn = new JComboBox(new String[] {
      "parabola", "circles 1", "circles 2", "eggbox 1", "eggbox 2" });
    selfn.setSelectedIndex(0);
    g.setConstraints(selfn, rc);  grid.add(selfn);

    bbar = new JPanel(new GridLayout(1, 2, 5, 5));
    bbar.setBorder(BorderFactory.createEmptyBorder(0, 5, 5, 3));
    btn = new JButton("Ok"); bbar.add(btn);
    btn.addActionListener(new AbstractAction () {
      public void actionPerformed (ActionEvent e) {
        dlg.setVisible(false);
        PSODemo.this.panel.setFn(selfn.getSelectedIndex());
        PSODemo.this.stat.setText("function set.");
      } } );
    btn = new JButton("Apply"); bbar.add(btn);
    btn.addActionListener(new AbstractAction () {
      public void actionPerformed (ActionEvent e) {
        PSODemo.this.panel.setFn(selfn.getSelectedIndex());
        PSODemo.this.stat.setText("objective function set.");
      } } );
    btn = new JButton("Cancel"); bbar.add(btn);
    btn.addActionListener(new AbstractAction () {
      public void actionPerformed (ActionEvent e) {
        dlg.setVisible(false);
    } } );

    dlg.getContentPane().add(grid, BorderLayout.CENTER);
    dlg.getContentPane().add(bbar, BorderLayout.SOUTH);
    dlg.setLocationRelativeTo(this);
    dlg.setLocation(664, 0);
    dlg.pack();
    return dlg;
  }  /* createFnSel() */

  /*------------------------------------------------------------------*/

  private JDialog createSwarm ()
  {                             /* --- create swarm dialog */
    final JDialog      dlg  = new JDialog(this,
                                          "Create Particle Swarm...");
    GridBagLayout      g    = new GridBagLayout();
    GridBagConstraints lc   = new GridBagConstraints();
    GridBagConstraints rc   = new GridBagConstraints();
    JPanel             grid = new JPanel(g);
    JPanel             bbar;
    JLabel             lbl;
    JTextArea          help;
    JButton            btn;

    grid.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
    lc.fill      =              /* fill fields in both directions */
    rc.fill      = GridBagConstraints.BOTH;
    rc.weightx   = 1.0;         /* resize only the input fields, */
    lc.weightx   = 0.0;         /* but not the labels */
    lc.weighty   = 0.0;         /* resize lines equally */
    rc.weighty   = 0.0;         /* in vertical direction */
    lc.ipadx     = 10;          /* gap between labels and inputs */
    lc.ipady     = 10;          /* make all lines of the same height */
    rc.gridwidth = GridBagConstraints.REMAINDER;

    lbl = new JLabel("Number of particles:");
    g.setConstraints(lbl, lc);     grid.add(lbl);
    final JSpinner parcnt = new JSpinner(
          new SpinnerNumberModel(30, 1, 999999, 1));
    g.setConstraints(parcnt, rc);  grid.add(parcnt);

    lbl = new JLabel("Tail length (history):");
    g.setConstraints(lbl, lc);     grid.add(lbl);
    final JSpinner tailen = new JSpinner(
          new SpinnerNumberModel(2, 0, 100, 1));
    g.setConstraints(tailen, rc);  grid.add(tailen);

    lbl = new JLabel("Seed for random numbers:");
    g.setConstraints(lbl, lc);     grid.add(lbl);
    final JSpinner seed = new JSpinner(
          new SpinnerNumberModel(0, 0, 999999, 1));
    g.setConstraints(seed, rc);    grid.add(seed);

    help = new JTextArea(
       "If the seed for the pseudo-random number generator\n"
      +"is set to zero, the system time will be used instead.");
    help.setFont(small);
    help.setBackground(this.getBackground());
    g.setConstraints(help, rc); grid.add(help);

    lbl = new JLabel("Acceleration factor:");
    g.setConstraints(lbl, lc);     grid.add(lbl);
    final JTextField accel = new JTextField("1");
    accel.setFont(font);
    g.setConstraints(accel, rc);   grid.add(accel);

    lbl = new JLabel("Initial deceleration factor:");
    g.setConstraints(lbl, lc);     grid.add(lbl);
    final JTextField decel = new JTextField("1");
    decel.setFont(font);
    g.setConstraints(decel, rc);   grid.add(decel);

    lbl = new JLabel("Deceleration factor decay:");
    g.setConstraints(lbl, lc);     grid.add(lbl);
    final JTextField decay = new JTextField("0.03");
    decay.setFont(font);
    g.setConstraints(decay, rc);   grid.add(decay);

    bbar = new JPanel(new GridLayout(1, 2, 5, 5));
    bbar.setBorder(BorderFactory.createEmptyBorder(0, 5, 5, 3));
    btn = new JButton("Ok"); bbar.add(btn);
    btn.addActionListener(new AbstractAction () {
      public void actionPerformed (ActionEvent e) {
        dlg.setVisible(false);
        int s = ((Integer)seed.getValue()).intValue();
        PSODemo.this.panel.createSwarm(
          ((Integer)parcnt.getValue()).intValue(),
          ((Integer)tailen.getValue()).intValue(),
          Double.parseDouble(accel.getText()),
          Double.parseDouble(decel.getText()),
          Double.parseDouble(decay.getText()),
          (s != 0) ? new Random(s) : new Random());
        PSODemo.this.stat.setText("swarm created");
      } } );
    btn = new JButton("Apply"); bbar.add(btn);
    btn.addActionListener(new AbstractAction () {
      public void actionPerformed (ActionEvent e) {
        int s = ((Integer)seed.getValue()).intValue();
        PSODemo.this.panel.createSwarm(
          ((Integer)parcnt.getValue()).intValue(),
          ((Integer)tailen.getValue()).intValue(),
          Double.parseDouble(accel.getText()),
          Double.parseDouble(decel.getText()),
          Double.parseDouble(decay.getText()),
          (s != 0) ? new Random(s) : new Random());
        PSODemo.this.stat.setText("swarm created");
      } } );
    btn = new JButton("Close"); bbar.add(btn);
    btn.addActionListener(new AbstractAction () {
      public void actionPerformed (ActionEvent e) {
        dlg.setVisible(false); } } );

    dlg.getContentPane().add(grid, BorderLayout.CENTER);
    dlg.getContentPane().add(bbar, BorderLayout.SOUTH);
    dlg.setLocationRelativeTo(this);
    dlg.setLocation(664, 94);
    dlg.pack();
    return dlg;
  }  /* createSwarm() */

  /*------------------------------------------------------------------*/

  private String msg ()
  {                             /* --- create status message */
    if (this.fmt == null) this.fmt = new DecimalFormat("0.000000");
    return "step: "     +this.panel.getStep()
          +", best: f(" +this.fmt.format(this.panel.getBestX())
          +","          +this.fmt.format(this.panel.getBestY())
          +") = "       +this.fmt.format(this.panel.getBest());
  }  /* msg() */

  /*------------------------------------------------------------------*/

  private void updateSwarm (int epochs, int delay)
  {                             /* --- move the swarm */
    if (this.cnt >= 0) {        /* check for running update */
      this.timer.stop(); this.cnt = -1; return; }
    if (!this.panel.hasSwarm()) return;
    if (delay <= 0) {           /* if to update at the end */
      while (--epochs >= 0)     /* while more epochs to compute, */
        this.panel.updateSwarm();              /* move the swarm */
      this.panel.repaint();     /* redraw the window contents */
      this.stat.setText(this.msg());
      return;                   /* show a status message, */
    }                           /* then abort the function */
    this.cnt   = epochs;        /* note the epochs */
    this.timer = new Timer(delay, new ActionListener () {
      public void actionPerformed (ActionEvent e) {
        if (--PSODemo.this.cnt < 0) {
          PSODemo.this.timer.stop(); return; }
        PSODemo.this.panel.updateSwarm();     /* move the swarm and */
        PSODemo.this.panel.repaint(); /* redraw the window contents */
        PSODemo.this.stat.setText(PSODemo.this.msg());
      } } );                    /* update the status text */
    this.timer.start();         /* start the status update timer */
  }  /* updateSwarm() */