Discete Event Simulation Question (Code) ?

[Avin Sinanan]

Hello this question definite falls under Advanced.
I've created the code to to the following. Its actually 3 classes of code. Any help would be appreciated.
here what it does and hereare the problems am having with it. Thanks again for reading:
Explanation of code
This code is for Discrete Event Simulation Techniques.
The code written creates a number of classes. Mainly it has the classes MS1 , MS2 and BTS1 and BTS2,
MS1 sends signals to BTS1 and MS2 sends signals to BTS2.
MS1and BTS1 has no connection to MS2 and MTS2.
How does signals go from MS1 to BTS1? It sends the signals to the class Signals. Signals then sends the signals o the class Queue which is like a cable or line in real life. Hence a cable called queueMStoBTS which is an object of class Queue connects MS1 and BTS1.
Now the for MS2 and BTS2 the same thing happens. Except the class Signals is replaced by SignalsMS2 and Queue is replaced by class QueueMS2 and its object is queueMS2toBTS2.
Now the only connection between MS1/BTS1 and MS2/BTS2 is that when the simulation is being performed signals running from MS1 to BTS1 and from MS2 toBTS2 occurs in parallel ( at the same time).
Now the Simulation is performed for 610 time units. And every 10 time units a sample of the amount of bytes ( signals are measured in bytes ) flowing through each queue is measured and that value is put into an array which stores the value. This is done for both MS1/BTS1 and MS2.BTS2.
In the end a graph is plotted with bytes at each 10 units time VS time.
Hence am suppose to get 2 graphs at the end. One for MS1/BTS1 and MS2/BTs2.
My problem is that the simulation does not run for the full 610 time units. It stop sometimes at 3 units. And the only time the graphs can be printed is when the time unit exceeds 600 time units and since the time units never exceeds 600 the graphs are never plotted.
Could you give it a look please. I worked really hard on this one.
Thanks… Avin
And here are the classes..remember its three classes..

import java.util.Random.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.util.*;
import DESimGraph.*;
import MS2.*;
class DESim extends Simulator
{
     public static void main(String[] args) 
    {
       new DESim().start();
     }
    void start()
    {
      events = new ListQueue();
    
    /* We have to create the Mobile station, Queue and BTS */

BTS1 bts1 = new BTS1();
       Queue queueMStoBTS = new Queue();
Signals sig = new Signals() ;
    MS1 ms1 = new MS1();
    
    BTS2 bts2 = new BTS2();
    QueueMS2 queueMS2toBTS2 = new QueueMS2();
    SignalsMS2 sigMS2 = new SignalsMS2();
    MS2 ms2 = new MS2();
    
    /*After creating them we have to connect all of them*/
    
    sig.queueMStoBTS = queueMStoBTS;
    queueMStoBTS.bts1 = bts1;
    bts1.queueMStoBTS = queueMStoBTS;

sigMS2.queueMS2toBTS2 =queueMS2toBTS2 ;
queueMS2toBTS2.bts2 = bts2 ;
bts2.queueMS2toBTS2 = queueMS2toBTS2 ;
    
    /*Make the mobile station start creating signals immediately */
    
    sig.time = 0.0;
    sigMS2.time = 0.0 ;
    
    ms1.time = 0.0 ;
    ms2.time = 0.0;
    
    
    insert(sig);
    insert(ms1);
    insert(sigMS2);
    insert(ms2);
    
    
   doAllEvents();
    }
}
/*------------MOBILE STATION ONE------------------------------------*/
/*This class generates signals and puts it in the Signals Class.
The Signals class then puts it into the Queue.
And the Queue then transports these signals to the BTS1 class.
This code is an extension of the "Build a Discete Event Simulation
Class MS2 is a basic replica of this class.
in Ten Easy Steps.. thats why it looks familar.
*/
class MS1 extends Event
{
private Vector msSignals = new Vector();

String handoff = "120";
String locationUpdate = "1250";
String callSetup = "3000";
String callEnd = "350" ;

public MS1()
{
msSignals.addElement(handoff);
msSignals.addElement(locationUpdate);
msSignals.addElement(callSetup);
msSignals.addElement(callEnd);
}

void execute(AbstractSimulator simulator) 
{

time += Random.exponential(1.0);

        if (time <= 610.0) 
        {
        int number =(int)(Math.random()*3);
        String size = (String) msSignals.elementAt(number);
        Signals.method1(size);
        simulator.insert(this);
}
}
}
 

/*--------------MS1  signals are put here---------------------*/
class Signals extends Event
{
Queue queueMStoBTS ;

static int i =0;
static private java.util.Vector inputSignals = new java.util.Vector();

public Signals()
{
}

void execute(AbstractSimulator simulator) 
{

queueMStoBTS.insert(simulator ,Signals.method());
time += Random.exponential(1.0);
        if (time <= 610.0) 
        {
        simulator.insert(this);
}
}


static public void method1(String input)
{
inputSignals.addElement(input);
}

    static public String method()
{
String signal = (String) inputSignals.firstElement();
    inputSignals.removeElementAt(0);
return signal ;
}
}
/*------------------------------------------------*/
class Queue 
{
BTS1 bts1 ;
static int totalBytes = 0;
static double timeNow =0 ;
static double timeBelow =0;

/* A vector is cerated to hold siganals */
static private java.util.Vector signals = new java.util.Vector();

void insert( AbstractSimulator simulator ,String signal)
{
if(bts1.isAvaiable())
{


   //int bytes = Integer.valueOf(signal).intValue();
   int bytes = Integer.parseInt(signal);
   
   totalBytes = totalBytes + bytes ;
   
        timeNow = ((Simulator)simulator).now();
        
        
        if(timeNow <= (timeBelow + 10))
        {
        
   System.out.println("Total Bytes" + totalBytes);
   
   }
   if(timeNow >  (timeBelow + 10))
   {
   //Send total byes and time now tp 2 matrices
 
   int timeNowInt = (int)(timeNow);
   
   DynamicArray.arrayMethod1(totalBytes);
   DynamicArray.arrayMethod(timeNowInt);
   totalBytes = 0;
   timeBelow = timeBelow + 10 ;
   
   
   
   
   }
   
   if(timeNow > 600)
   {
   DynamicArray.print();
   
   }
   bts1.insert(simulator , signal);
   
}
else
{
signals.addElement(signal);
}
}
int size() 
{
        return signals.size();
    }
    
   String remove() 
   {
    String signal = (String) signals.firstElement();
    signals.removeElementAt(0);
       return signal;
   }

}

/*-----------------------------------------------------------------*/
class BTS1 extends Event
{
private String signalNumberServe ;
Queue queueMStoBTS ;

void execute(AbstractSimulator simulator) 
{
System.out.println("Finished processing bytes " + signalNumberServe + " at time " + time);
signalNumberServe = null ;
if( queueMStoBTS.size()> 0)
{
String signalNumber = queueMStoBTS.remove();
insert((Simulator) simulator, signalNumber);
}
}

boolean isAvaiable()
{
 return (signalNumberServe == null);
}

void insert(AbstractSimulator simulator ,String signal)
{
signalNumberServe = signal ;
double serviceTime = Random.exponential(0);
        time = ((Simulator)simulator).now() + serviceTime;
        simulator.insert(this);
}
}
/*---------------------Global---------------------------*/
class Global
{
static public int totalSize =0 ;
static public int totalSizeMS2 =0 ;

}

/*---------------------MATRIX---------------------------*/
class DynamicArray
{
static private int i ;
static private int l;
static private int data[] = new int[1];
static private int data1[] = new int[1];
static private int newdata[];
static private int newdata1[];
static private int k=0;
static private int q=0;
static private int newSize;
static private int newSize1;

public DynamicArray(){}

static void arrayMethod(int j)
{
 i = j ;
 if(k==data.length)
 {
 newSize = data.length +1;
 int[] newData = new int[newSize];
 System.arraycopy(data, 0, newData, 0, data.length);
 data = newData;
            data[k] = i;
 }
 else
 {
 data[k]=i;
 }
 
 k++;
 
}


static void arrayMethod1(int m)
{
 l = m ;
 if(q==data1.length)
 {
 newSize1 = data1.length+1;
 Global.totalSize = newSize1 ;
 int[] newData1 = new int[newSize1];
 System.arraycopy(data1, 0, newData1, 0, data1.length);
 data1 = newData1;
            data1[q] = l;
 }
 else
 {
 data1[q]=l;
 System.out.println("Nope ");
 }
 
 q++;
 
}



static void print()
{
System.out.println("here ");


int ee = data.length ; 
int ff = data1.length ;

System.out.println("" + ee );
System.out.println("" + ff );

for(int ll =0 ; ll < ee ; ll++)
{
System.out.println("" + data[ll]);
}

for(int hh =0 ; hh < ff ; hh++)
{
System.out.println("" + data1[hh]);
}


DESimGraph graph = new DESimGraph(data , data1) ;
}
}

import java.util.Random.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.util.*;
import DESimGraph.*;

class MS2 extends Event
{
String size1 = "1000" ;

void execute(AbstractSimulator simulator) 
{

time += Random.exponential(1.0);

      if (time <= 610.0) 
       {
        SignalsMS2.method1(size1);
        simulator.insert(this);
        }
}
}

/*--------------MS2  signals are put here---------------------*/
class SignalsMS2 extends Event
{
QueueMS2 queueMS2toBTS2 ;

static int i =0;
static public java.util.Vector inputSignalsMS2 = new java.util.Vector();

public SignalsMS2()
{
}

void execute(AbstractSimulator simulator) 
{
                         queueMS2toBTS2.insert(simulator ,SignalsMS2.method());
                         time += Random.exponential(1.0);
        if (time <= 610.0) 
        {
        simulator.insert(this);
        }
}


static public void method1(String input)
{
inputSignalsMS2.addElement(input);
}

  static public String method()
{
String signal1 = (String) inputSignalsMS2.firstElement();
    inputSignalsMS2.removeElementAt(0);
return signal1 ;
}
}
/*------------------------------------------------*/
class QueueMS2 
{
BTS2 bts2 ;
static private int totalBytes = 0;
static private double timeNow =0 ;
static private double timeBelow =0;

/* A vector is cerated to hold siganals */
private java.util.Vector signalsMS2 = new java.util.Vector();

void insert( AbstractSimulator simulator ,String signal)
{
if(bts2.isAvaiable())
{


   //int bytes = Integer.valueOf(signal).intValue();
   int bytes = Integer.parseInt(signal);
   
   totalBytes = totalBytes + bytes ;
   
   timeNow = ((Simulator)simulator).now();
        
        
  if(timeNow <= (timeBelow + 10))
   {
        
    System.out.println("Total Bytes" + totalBytes);
   
   }
   if(timeNow >  (timeBelow + 10))
   {
         //Send total byes and time now tp 2 matrices
                    int timeNowInt = (int)(timeNow);   
   
DynamicArray2.arrayMethod1(totalBytes);
DynamicArray2.arrayMethod(timeNowInt);
 totalBytes = 0;
timeBelow = timeBelow + 10 ;
   
   }
   
   if(timeNow > 600)
   {
   DynamicArray2.print();
   
   }
   bts2.insert(simulator , signal);
   
}
else
   {
signalsMS2.addElement(signal);
  }
}
int size() 
{
        return signalsMS2.size();
    }
    
   String remove() 
   {
    String signal = (String) signalsMS2.firstElement();
    signalsMS2.removeElementAt(0);
    return signal;
   }

}

/*-----------------------------------------------------------------*/
class BTS2 extends Event
{
private String signalNumberServe ;
QueueMS2 queueMS2toBTS2 ;

void execute(AbstractSimulator simulator) 
{
System.out.println("BTS2 finished  processing " + signalNumberServe + " at time " + time);
signalNumberServe = null ;
if( queueMS2toBTS2.size()> 0)
{
  String signalNumber = queueMS2toBTS2.remove();
   nsert((Simulator) simulator, signalNumber);
}
}

boolean isAvaiable()
{
 return (signalNumberServe == null);
}

void insert(AbstractSimulator simulator ,String signal)
{
        signalNumberServe = signal ;
        double serviceTime = Random.exponential(0);
        time = ((Simulator)simulator).now() + serviceTime;
        simulator.insert(this);
}
}
/*---------------------MATRIX---------------------------*/
class DynamicArray2
{
static private int i ;
static private int l;
static private int data[] = new int[1];
static private int data1[] = new int[1];
static private int newdata[];
static private int newdata1[];
static private int k=0;
static private int q=0;
static private int newSize;
static private int newSize1;

public DynamicArray2(){}

static void arrayMethod(int j)
{
 i = j ;
 if(k==data.length)
 {
 newSize = data.length +1;
 int[] newData = new int[newSize];
 System.arraycopy(data, 0, newData, 0, data.length);
 data = newData;
                              data[k] = i;
 }
 else
 {
     data[k]=i;
 }
 
                    k++;
               }


static void arrayMethod1(int m)
{
 l = m ;
 if(q==data1.length)
 {
    newSize1 = data1.length+1;
   Global.totalSizeMS2 = newSize1 ;
    int[] newData1 = new int[newSize1];
    System.arraycopy(data1, 0, newData1, 0, data1.length);
   data1 = newData1;
            data1[q] = l;
 }
 else
 {
 data1[q]=l;
 System.out.println("Nope ");
 }
 
 q++;
 
}



static void print()
{
System.out.println("here ");

int ee = data.length ; 
int ff = data1.length ;

System.out.println("" + ee );
System.out.println("" + ff );

for(int ll =0 ; ll < ee ; ll++)
{
     System.out.println("" + data[ll]);
}

for(int hh =0 ; hh < ff ; hh++)
{
    System.out.println("" + data1[hh]);
}


DESimGraph graphMS2toBTS2 = new DESimGraph(data , data1) ;
}
}

import java.util.Random.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.util.*;
/*---------------------DESim ADD GRAPH-------------------*/
/*This class takes the values stored in the Dynamic Arrays 
makes a point to  point graph out of them.
*/

class DESimGraph
{
    private int[] data ;
    private int[] data1;

public DESimGraph(int[] dataEx , int[] data1Ex)
{
data = dataEx ;
data1 = data1Ex;

Plot plot = new Plot(data , data1);
plot.setLayout(null);
JFrame frame = new JFrame();
frame.setBackground(Color.white);

frame.setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent we) {
System.exit(0);
}
});

frame.getContentPane().add(plot);
plot.updateUI();
  frame.setSize(800,800);
frame.setVisible(true);
System.out.println("Now");
try {
Thread.sleep(500000);
} catch (Exception e) {}
     }
}
class Plot extends JPanel
{
        int[] x ; 
        int[] y ; 
        int size = Global.totalSize ;
        int[] xx = new int[size];
        int[] yy = new int[size];
        String xlabel, ylabel, title;
        int xdim, ydim, yzero, xzero, xdraw, ydraw;
        double xtic, ytic, xpoint, ypoint;
        double xmax, xmin, ymax, ymin; 
        static double x1max ;
       static double x1min ;


public Plot(int[] dataEx , int[] data1Ex)
{
System.out.println("Yep ");

x = dataEx ;
y = data1Ex ;



        xdim = 600;
        ydim = 600;
         xtic = 100;
         ytic = 5000;
         xlabel = ("Time");
         ylabel = ("Bytes");
            title = ylabel + " versus " + xlabel;

           xmax = x[0];
            xmin = x[0];
            ymax = y[0];
            ymin = y[0];
            x1min= x[0];
            x1max= x[0];
                for (int i=0; i < size; i++){
                if (x[i] > xmax) {
                xmax = x[i];
                }
                        if (x[i] < xmin) {
                        xmin = x[i];
                        
                        }
                        if (y[i] > ymax) {
                        ymax = y[i];
                        x1max = x[i];
                        }
                        if (y[i] < ymin) {
                        ymin = y[i];
                        x1min = x[i];
                        }
                        
                }
        
        
        //xx and yy are the scaled x and y used for plotting
                                
                for (int i=0; i < size; i++){
               xx[i] = (int) (50 + (((x[i]-xmin)/(xmax-xmin)) * (xdim-100)));
                yy[i] = (int) ((ydim - 50) - (((y[i]-ymin)/(ymax-ymin)) * (ydim-100)));
                }
                
//Find Zero point on y-axis required for drawing the axes
                
                if ((ymax*ymin) < 0){
                yzero = (int) ((ydim - 50) - (((0-ymin)/(ymax-ymin)) * (ydim-100)));
                }
                else{
                yzero = (int) ((ydim - 50) - ((0/(ymax-ymin)) * (ydim-100)));
                }
                
//Find zero point on x-axis required for drawing the axes
                
                if ((xmax*xmin) < 0) {
                xzero = (int) (50 + (((0-xmin)/(xmax-xmin)) * (xdim-100)));
                }
                else{
                xzero = (int) (50 + ((0/(xmax-xmin)) * (xdim-100)));
                }
                
//Now ready to plot the results
                repaint();     
                
              
  
  }
  
  
  public void paint(Graphics g){   
                
     Font f1 = new Font("TimesRoman", Font.PLAIN, 10);
    g.setFont(f1);
                
//First draw the axes
                 
//y-axis
                
                g.drawLine(xzero, 50, xzero, ydim-50);
                g.drawLine(xzero, 50, (xzero - 5), 55);
                g.drawLine(xzero, 50, (xzero + 5), 55);
                                
//x-axis
                
                g.drawLine(50, yzero, xdim-50, yzero);
                g.drawLine((xdim-50), yzero, (xdim-55), (yzero + 5));
                g.drawLine((xdim-50), yzero, (xdim-55), (yzero - 5));
                
//Initialise the labelling taking into account the xtic and ytic values
                                
                //x-axis labels
                
                if (xmin <= 0){
                xpoint = xmin - (xmin%xtic);
                }else{
                        xpoint = xmin - (xmin%xtic) + xtic;
                }
                
                do{
                xdraw = (int) (50 + (((xpoint-xmin)/(xmax-xmin))*(xdim-100)));
                g.drawString(xpoint + "", xdraw, (yzero+10));
                xpoint = xpoint + xtic;
                }while (xpoint <= xmax);
                
                if (ymin <= 0){
                ypoint = ymin - (ymin%ytic);
                }else{
                        ypoint = ymin - (ymin%ytic) + ytic;
                }
                
                do{
                ydraw = (int) ((ydim - 50) - (((ypoint - ymin)/(ymax-ymin))*(ydim-100)));
                g.drawString(ypoint + "", (xzero - 20), ydraw);
                ypoint = ypoint + ytic;
                }while (ypoint <= ymax);
//Titles and labels
                Font f2 = new Font("TimesRoman", Font.BOLD, 14);
                g.setFont(f2);
                g.drawString(xlabel, (xdim - 100), (yzero + 25));
                g.drawString(ylabel, (xzero - 25), 40);
                g.drawString(title, (xdim/2 - 75), 20);

//Finding Maximum and Minimun values for the curve


        
                
// Draw Lines
        
      g.drawString("Maximum point" + "("+ x1max + "," + ymax + ")", (xdim/2 + 250), 170);
     g.drawString("Minimum point" + "("+ x1min + "," + ymin + ")", (xdim/2 + 250), 200);
     
                for (int j = 0; j < size-1; j++)
                {
                
                        g.drawLine(xx[j], yy[j], xx[j+1], yy[j+1]);  
                }  
                
                
        }
  
  

}

interface Comparable {
    boolean lessThan(Comparable y);
}
abstract class AbstractEvent implements Comparable {
    abstract void execute(AbstractSimulator simulator);
}
abstract class OrderedSet {
    abstract void insert(Comparable x);
    abstract Comparable  removeFirst();
    abstract int size();
}
    
class AbstractSimulator {
    OrderedSet events;
    void insert(AbstractEvent e) {
        events.insert(e);
    }
    AbstractEvent cancel(AbstractEvent e)  {
        throw new java.lang.RuntimeException("Method not implemented");
    }
}

abstract class Event extends AbstractEvent {
    double time;
    public boolean lessThan(Comparable y) {
        Event e = (Event) y;  // Will throw an exception if y is not an Event
        return this.time < e.time;
    }
}
class Simulator extends AbstractSimulator {
    double time;
    double now() {
        return time;
    }
    void doAllEvents() {
        Event e;
        while ( (e= (Event) events.removeFirst()) != null) {
            time = e.time;
            e.execute(this);
        }
    }
}

class ListQueue extends OrderedSet {
    java.util.Vector elements = new java.util.Vector();
    void insert(Comparable x) {
        int i = 0;
        while (i < elements.size() && ((Comparable) elements.elementAt(i)).lessThan(x)) {
            i++;
        }
        elements.insertElementAt(x,i);
    }
    Comparable removeFirst() {
        if (elements.size() ==0) return null;
        Comparable x = (Comparable) elements.firstElement();
        elements.removeElementAt(0);
        return x;
    }
    Object remove(Object x) {
        for (int i = 0; i < elements.size(); i++) {
            if (elements.elementAt(i).equals(x)) {
               Object y = elements.elementAt(i);
               elements.removeElementAt(i);
               return y;
            }
        }
        return null;
    }
    public int size() {
        return elements.size();
    }
}

[ February 25, 2002: Message edited by: Avin Sinanan ]
[ February 25, 2002: Message edited by: Avin Sinanan ]
[ February 26, 2002: Message edited by: Avin Sinanan ]
[ February 26, 2002: Message edited by: Avin Sinanan ]
[ February 26, 2002: Message edited by: Avin Sinanan ]
[ February 26, 2002: Message edited by: Avin Sinanan ]

[Dirk Schreckmann]

Hello,
I was with you up until the code. I'm too lazy to figure it out without some formatting. If you would post it formatted with the [ code ] and [ /code ] tags I'd take another look, and I'd guess that others might be more inclined to do so as well.
Good Luck

[Avin Sinanan]

Hey thanks Dirk,
Ok I did the code /code thing... did I do it correct.
I never actually did the formatting thing before.
So if it isn't correct please let me know and I'll give it another try.
What does the "code" thing do by the way?
Anyway thanks again..
Avin

[Jim Yingst]

Well, look at your code. Among other things, the [code] tag causes your code to be indented the way it was when you submitted it, rather than all flat against the left hand side of the page. Usually this is a good thing, as we would use indentation to show logical structure. In this case however, the indentation seems to jump about at random, without apparent logic. So it doesn't actually help anyone. I'd suggest you format the code carefully in a separate file first. Do not use tabs - ever - in code, as they are the spawn of Satan and display different widths on different computers (or even different programs), and are the primary cause of badly-formatted code. Things that look indented on one system, aren't when you move to another.
Plus, who needs 8 whole spaces of indentation per level? (On average.) I'd use 4 as an absolute maximum - with 2 being my own preference. See how wide the whole program is now above, as the tabs drive everything toward the right side of the screen? Ugh. When I have to use my horizontal scroll bar to see what a line does, there's something wrong. Use fewer spaces to indent, and that problem will go away.
On an unrelated note, what do MS1 and BTS1 mean? These names are extremely uninformative, and do nothing to help people understand what you're trying to do here.

[Avin Sinanan]

Ok Jim I'll format my code again and then post it up again. Thanks for the advice, it does make sense. Cause it can be annoying when someone has to use their scroll bar.
Oh MS means Mobile Station - its basically a celluar phone.
BTS means Base Transceiver Station - its the antennas that you see that receiver and send signals to and from your celluar phone. Some times you see them when you are driving in your car. They are bascially huge antennas that the celluar company uses.
As you can guess by now am doing a project on simulating a GSM celluar network, where GSM is European standard for celluar commnication and after that I have to do an IS-41 network which is the american version of GSM.
Am suppose to measure the amount of bytes being between each component in the network. An well the MS and BTS are 2 possible compoenets in the network. There are many others but I have reached that point in the project yet.
oh and since there are more than one MS and BTS I gave it the names MS1 and BTS1 and MS2 and BTS2 to keep track of how much there is in the network.
Thank again for reading and the advice.
yours resepctfully Avin Sinanan

[Avin Sinanan]

Hello again,
I've edited and formatted the code. It looks a bit better now.
If its not good enough please let me know and I'll do some more formatting ok.
Thanks again for all the advice so far.
Yours respectively Avin Sinanan

[Avin Sinanan]

Hey I realized I forgot to post some classes.
I just posted the missing classes ( Its within the first posting). Its about 5 extra classes. But the 5 extra classes are short.
Thanks for having some patience with me.
Yours respectuflly Avin Sinanan