umontreal.iro.lecuyer.examples.QueueObs2 Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of ssj Show documentation

SSJ is a Java library for stochastic simulation, developed under the direction of Pierre L'Ecuyer, in the Département d'Informatique et de Recherche Opérationnelle (DIRO), at the Université de Montréal. It provides facilities for generating uniform and nonuniform random variates, computing different measures related to probability distributions, performing goodness-of-fit tests, applying quasi-Monte Carlo methods, collecting (elementary) statistics, and programming discrete-event simulations with both events and processes.

The newest version!

import java.util.Observer;
import java.util.Observable;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import umontreal.iro.lecuyer.stat.*;
import umontreal.iro.lecuyer.simevents.*;
import umontreal.iro.lecuyer.rng.*;
import umontreal.iro.lecuyer.probdist.ExponentialDist;
import umontreal.iro.lecuyer.randvar.RandomVariateGen;

public class QueueObs2 {
   static final double meanArr  = 10.0;
   static final double meanServ =  9.0;
   static final int numCust     = 50000;

   RandomVariateGen genArr   = new RandomVariateGen
               (new MRG32k3a(), new ExponentialDist (1.0/meanArr));
   RandomVariateGen genServ  = new RandomVariateGen
               (new MRG32k3a(), new ExponentialDist (1.0/meanServ));
   Tally waitingTime = new Tally
      ("Customers waiting time");
 
   public static void main (String[] args) { 
      QueueObs2 qb = new QueueObs2();
      SpyWindow sw = new SpyWindow (qb);
      qb.waitingTime.setBroadcasting (true);
      qb.waitingTime.addObservationListener (sw);
      sw.pack();
      sw.setVisible(true);
      qb.simulation();
      System.out.println (qb.waitingTime.report());
      System.exit (0);
   }

   public void simulation() {
      double Wi = 0.0;
      waitingTime.add (Wi);
      for (int i = 2; i <= numCust; i++) {
         Wi += genServ.nextDouble() - genArr.nextDouble();
         if (Wi < 0.0)
            Wi = 0.0;
         waitingTime.add (Wi);
      }
   }
}

class SpyWindow extends JFrame implements ObservationListener {
   private int nObs = 0;
   private JTextArea obs = new JTextArea (25, 80);
   private JScrollPane sp = new JScrollPane (obs);
   private QueueObs2 qb;

   public SpyWindow (QueueObs2 qb) {
      super ("Observation spy");
      this.qb = qb;
      sp.getViewport().setScrollMode (JViewport.BACKINGSTORE_SCROLL_MODE);
      setContentPane (sp);
      setDefaultCloseOperation (WindowConstants.DO_NOTHING_ON_CLOSE);
      addWindowListener (new WindowClose());
   }

   public void newObservation (StatProbe probe, double x) {
      Rectangle vrect = sp.getViewport().getViewRect();
      Dimension vsize = sp.getViewport().getViewSize();
      boolean rescroll = vrect.y+vrect.height == vsize.height;
      obs.append
	 ("Customer " + (nObs++) + " waited " + x + " minutes.\n");
      synchronized (sp) {
	 JViewport vp = sp.getViewport();
	 vsize = vp.getViewSize();
	 vp.scrollRectToVisible
	    (new Rectangle (0, vsize.height - 15, vsize.width, vsize.height));
      }
   }

   class WindowClose extends WindowAdapter {
      public void windowClosing (WindowEvent ev) {
	 qb.waitingTime.removeObservationListener (SpyWindow.this);
	 dispose();
      }
   }
}