Traffic Light System

[wyatt]

i need source code

[Fu-Kwun Hwang]

It is available as attachment under the first posted message. Please download it by yourself if you need it.
It is just a click away. :-)

[ericsson]

can help me in my source coding with Assembly Code for microP 68000 that use output LED & 7 segments. its for traffic light system???

[mazen]

Dear Sir,
it's wonderfull simulation,i like it, could you please send me the source code for traffic control.

To: soso_ali994@hotmmail.com
Or : hardzep11@hotmail.com

Thanks & regards

[Fu-Kwun Hwang]

The source code is available as attached file at the first message (where you find the simulation).
Please download it by yourself if you really need it!

[mazen]

Thank You..

[laramsf]

I'm having trouble little ..How do I get a Java program ...Because the version that I do not work well incomplete .. and it bad version
Can you send a Java program in email or give me a site.
(Sorry for the inconvenience)

[laramsf]

plz can u give me source code of traffic light system

[Fu-Kwun Hwang]

As I have replied, the source code is available for download.
This version was created more than 17 years ago with JDK1.0.2
I just compiled with JDK1.0.2 and it is working fine.
You might be able to modified some of the code if you are familiar with java. 
The source code is listed again.

import java.awt.*;
import java.util.*;

public class trafficControl extends java.applet.Applet implements Runnable{
   Dimension offDimension;
   Image bgImage,fgImage;
   Light L;
   Traffic T;
   TextField countText,scoreText,XYpos;
   int numLight=3,numSection=numLight+1;
   String rts,STR[]={"Reset","Start","Time","maxVelocity","Acceleration","delayTime","lighttime"};
   Color bgColor=new Color(0xE0,0xE0,0xE0);//new Color(0xC8,0xDF,0xD0);
   public void init(){
      setBackground(bgColor);
      for(int i=0;i         if((rts=getParameter(STR))!=null)
            STR=new String(rts);
      }
      Panel p=new Panel();
      p.add(new Label("N1/N2"));
      p.add(countText=new TextField("0/0/0.00",12));
      countText.setEditable(false);
//      p.add(new Label("T="));
//      p.add(timeText=new TextField("0",3));
//      timeText.setEditable(false);
      p.add(new Label("n1/n2"));
      p.add(scoreText=new TextField("0/0/0.00",9));
      scoreText.setEditable(false);
      p.add(new Button(STR[1]));
      p.add(new Button(STR[0]));
      add("North",p);
      L=new Light(numLight,STR);
      T=new Traffic(L);
      String str;
      if((str=getParameter("accelerationValue"))!=null)
         T.a=Double.valueOf(str).doubleValue();
      if((str=getParameter("vmax"))!=null)
         car.vmax=Double.valueOf(str).doubleValue();
      reset();
   }

   public boolean action(Event ev, Object arg) {
      String label = (String)arg;
      if (ev.target instanceof Button) {
         if(label.equals(STR[1])){
            start();
         }else if(label.equals(STR[0])){
            reset();
         }
         return true;
      }
      return false;
   }

   Graphics g,g0,gb;
   Dimension area;
   void reset(){
      //stop();
      area=size();
      if ( (g == null) ){
//            || (area.width != bgDimension.width)
//            || (area.height != bgDimension.height) ) {
//         bgDimension = area;
         bgImage = createImage(area.width, area.height);
         fgImage = createImage(area.width, area.height);
         g = bgImage.getGraphics();
         g0=fgImage.getGraphics();//getGraphics();
      }
      runTime=0;
      lastTime = System.currentTimeMillis();
      g.setColor(bgColor);
      g.fillRect(0,0,area.width,area.height);
      g.setColor(Color.black);
      drawRoad(area);
      gb=this.getGraphics();
   }
   numberInput maxV,acceleration;
   void drawRoad(Dimension area){
      L.init(g,area);
      T.init(g0,L.X[0],L.y-5,area.width);
      maxV=new numberInput(g,5,L.y,STR[3]);
      maxV.setValue((int)car.vmax,5,50);
      acceleration=new numberInput(g,10,L.y+L.lSize.height,STR[4]);
      acceleration.setValue((int)T.a,1,20);
      repaint();
   }
   static boolean running,rightClick,changed=false;
   public boolean mouseDown(Event e, int x, int y){
      if(e.modifiers==Event.META_MASK)//"Right Click, ";
         rightClick=true;
      else rightClick=false;
      int w=L.lSize.width;
      if(L.mouseDown(e,x,y)){
         repaint();
         return true;
      }else if(x< 2*w && y<3*w){
         int sign=0;
         if(e.modifiers==Event.META_MASK || x>w)sign=1;//right click
         else if((L.greenTime>1)&&
                  (L.yellowTime-L.greenTime)>1 &&
                  (L.redTime-L.yellowTime)>1 )
                  sign=-1; // right click add 1, left click sub 1
      
         switch(y/w){
            case 0:L.greenTime+=sign;
            case 1:L.yellowTime+=sign;
            case 2:L.redTime+=sign;
         }
         L.setupLightTime(L.greenTime,L.yellowTime,L.redTime);
         repaint();
      }else if(maxV.mouseDown(e,x,y)){
         car.vmax=maxV.value();
         repaint();
      }else if(acceleration.mouseDown(e,x,y)){
         T.a=acceleration.value();
         repaint();
      }else{
         running=!running;
         changed=true;
         repaint();
      }
      return true;
   }
   //public boolean mouseDrag(Event e, int x, int y){
      //if(e.modifiers==Event.META_MASK)return true;
   //   return true;
   //}
   public boolean mouseUp(Event e, int x, int y){
      if(changed){
         if(!rightClick)running=!running;
         changed=false;
      }
      return true;
   }
   //public boolean mouseMove(Event e, int x, int y){
   //   XYpos.setText(String.valueOf(x)+","+String.valueOf(y));
   //   return true;
   //}
   public void paint(Graphics gs){
      if(g==null)reset();
      update(gs);
   }
   String d2String(double value){
      float f=(float)((int)(value*100.)/100.);
      String str=String.valueOf(f);
      if(str.indexOf(".")==-1)str+=".0";
      return str;
   }

   public void update(Graphics gs){

      g0.drawImage(bgImage, 0, 0, this);
      if(!running)L.drawTrace(g0,acceleration.value(),maxV.value());
      T.advanced(deltaT);
      T.drawVelocity(g0);
      g0.drawString(STR[2]+d2String(runTime)+" s",130,L.y-L.height);

      gs.drawImage(fgImage, 0, 0, this);
   }
   // animation code
   Thread animThread;
   long lastTime=0;
   double runTime;
   long delay=100,delta=100;
   //  This starts the threads.
   public void start(){
      //Start animating!
      if (animThread == null) {
         animThread = new Thread(this);
         animThread.start();
         //Remember the starting time. of thread
         lastTime = System.currentTimeMillis();
         runTime=0.;
      }
      running=true;
   }
    public void stop() {
      //Stop the animating thread.
      animThread = null;
   }
   int second=0;
   public void run() {
      //Just to be nice, lower this thread's priority
      Thread.currentThread().setPriority(Thread.MIN_PRIORITY);
      //This is the animation loop.
      while (Thread.currentThread() == animThread) {
         //Advance the animation frame. with delta time
         delta=System.currentTimeMillis()-lastTime;
         lastTime+=delta;
         if(running)advanced(delta/1000.);
         try {
            animThread.sleep(Math.max(0,lastTime-System.currentTimeMillis()));
         } catch (InterruptedException e) {
            break;
         }
      }
   }
   int lastN1=0,lastN2=0,period=100;
   String str="(0/0)=>";
   void showResult(){
      countText.setText(String.valueOf(T.passed)+"/"+
            String.valueOf(T.passed2)+"/"+
            String.valueOf((int)(100.*(T.passed+T.passed/3.)/second)/50.));
      //period=3*(L.redTime);
      if(second%period==0){
      double score=(T.passed-lastN1+(T.passed2-lastN2)/3.)/period;
      scoreText.setText(String.valueOf(T.passed-lastN1)+"/"+
            String.valueOf(T.passed2-lastN2)+"/"+
            String.valueOf((int)(100.*score)/50.));
         lastN1=T.passed;
         lastN2=T.passed2;
      }
   }
   double deltaT;
   void advanced(double dt){
      runTime += dt;
      int t=(int)runTime;
      L.setStatus(t);
//      T.advanced(dt);
      deltaT=dt;
      if(t!=second){
         second=t;
         //timeText.setText(String.valueOf(second));
         showResult();
      }
/*
      g0.drawImage(bgImage, 0, 0, this);
      if(!running)L.drawTrace(g0,acceleration.value(),maxV.value());
      T.advanced(deltaT);
      T.drawVelocity(g0);
      g0.drawString(STR[2]+d2String(runTime)+" s",130,L.y-L.height);
      //g.drawImage(fgImage, 0, 0, this);

      repaint();
*/
      update(gb);
   }
}

class Light{// implements Runnable{
   static int green=0,yellow=1,red=2,count;
   Color color[]={Color.green,Color.yellow,Color.red};
   int X[],status[],y;
   static int height=70;
   int greenTime,yellowTime,redTime;
   int delayArray[];
   Dimension lSize=new Dimension(10,30);
   Graphics g;
   int dd=3;
   numberInput delayControl[];
   int init_delay=4;
   String STR[];
   Light(int n,String s[]){
      count=n;
      X=new int[n];
      status=new int[n];
      delayArray=new int[n];
      delayControl=new numberInput[n-1];
      STR=s;
   }
   int xx,yy,size,size2;
   int width,roadWidth;
   void init(Graphics gi,Dimension area){
      roadWidth=15;
      width=(area.width-count*roadWidth)/count;
      int x0=width/2,dx=width+roadWidth,y0=area.height;
      height=(area.height-3*lSize.height/2-roadWidth)/2;
      g=gi;
      y=y0-height;
      xx=lSize.width+dd;
      yy=y+dd;
      size=lSize.width/2;
      size2=2*size;
      drawRoad(width,roadWidth);// draw streets
      for(int i=0;i         X=x0+i*dx;
         status=red;
         delayArray=0;
         drawLight(i,0);
      }
      // draw Left top cornor light
      Color c=g.getColor();
      g.drawRect(0,0,lSize.width,lSize.height);
      for(int i=0;i<3;i++){// 3 lights
         g.setColor(color);
         g.fillOval(0,i*lSize.width,size2,size2);
         g.setColor(Color.black);
         g.drawOval(0,i*lSize.width,size2,size2);
      }
      g.setColor(c);
/*
   if(STR[6].length>0){
      String delimeter=",";
      String[] lv=STR[6].split(delimeter);
      setupLightTime(Integer.parseInt(lv[0]),Integer.parseInt(lv[1]),Integer.parseInt(lv[2]));
   }else   
*/
      setupLightTime(30,35,70);
      for(int i=1;i         delayControl[i-1]=new numberInput(g,X-lSize.width-5,yy,STR[5],true);
      }
   }
   void drawRoad(int width,int roadWidth){
      int x=0;
      int w,h=height,dh=h+roadWidth;
      //int dd=5;
      //int xx=lSize.width+dd,yy=dd;
      for(int i=0;i         if(i==count || i==0 )w=width/2;
         else w=width;
         g.drawRect(x,y,w,h-1); // lower part
         g.drawRect(x,y-dh,w,h); // upper part
         for(int j=y-dh+h;j>y-dh;j-=10)g.drawLine(x,j,x+5,j);
         for(int j=y-dh+h;j>y-dh;j-=20)g.drawLine(x+5,j,x+10,j);
         x=x+w+roadWidth;
      }
   }

   public boolean mouseDown(Event e, int x, int y){
      for(int i=1;i         if(delayControl[i-1].mouseDown(e,x,y)){
            setupDelay(i,delayControl[i-1].lastChange());
            return true;
         }
      }
      return false;
   }

   void drawLight(int n,int ts){
      // draw Light according to current status
      Color c=g.getColor();
      int x1=X[n]-xx;
      g.clearRect(x1,yy,lSize.width,lSize.height);
      g.drawRect(x1,yy,lSize.width,lSize.height);
      for(int i=0;i<3;i++)
         g.drawOval(x1,yy+i*lSize.width,size2,size2);

      g.setColor(Color.black);
      g.fillRect(x1-size,yy+5*lSize.width-12,16,14);
      g.setColor(color[status[n]]);
      g.fillOval(x1,yy+status[n]*lSize.width,size2,size2);
      g.drawString(String.valueOf(ts),x1-size,yy+5*lSize.width);
      g.setColor(c);
   }
   void setupLightTime(int tGreen,int tYellow, int tRed){
      greenTime=tGreen;
      yellowTime=tYellow;
      redTime=tRed;
      g.clearRect(2*size2,0,30,3*size2);
      Color c=g.getColor();
      g.setColor(Color.black);
      g.drawString(String.valueOf(greenTime),2*size2,size2);
      g.drawString(String.valueOf(yellowTime-greenTime),2*size2,2*size2);
      g.drawString(String.valueOf(redTime-yellowTime),2*size2,3*size2);
      //drawTiming(running);
      g.setColor(c);
   }
   void drawTrace(Graphics gp,double a,double maxV){
      int xi=width/2+1,xx=xi;
      int yi=y+height;
      double x=0.;//,vx=0.;
      double t,ta=maxV/a,ta2=ta*ta;
      a=a/2.;
      Color c=gp.getColor();
      drawTiming(gp);
      gp.setColor(Color.blue);
      for(t=0.;yi>y-height;t+=0.5){
         if(t         else gp.drawLine(xx,yi,xx=xi+(int)(a*ta2+maxV*(t-ta)),yi--);
         //if(t         //else gp.drawLine(xx=xi+(int)(a*ta2+maxV*(t-ta)),yi--,xx,yi);
      }
      gp.setColor(c);
   }
   void drawTiming(Graphics gp){
      //draw light timing info
      Color c=gp.getColor();
      int xi=width/2,yi;
      for(int i=0;i         gp.setColor(Color.white);
         gp.drawLine(xi,y+height,xi,y-height);
         //if(status){
         //   gp.setColor(Color.black);
         //   gp.drawLine(xi,y+height,xi,y);
         //   gp.drawLine(xi,y-roadWidth,xi,y-height);
         //}else{
            yi=y+height-2*delayArray;
            while(yi>y-height){
               gp.setColor(Color.green);
               gp.drawLine(xi,yi,xi,yi-=2*greenTime);
               gp.setColor(Color.yellow);
               gp.drawLine(xi,yi,xi,yi-=2*(yellowTime-greenTime));
               gp.setColor(Color.red);
               gp.drawLine(xi,yi,xi,yi-=2*(redTime-yellowTime));
            }
            yi=y+height-2*delayArray;
            while(yi               gp.setColor(Color.red);
               gp.drawLine(xi,yi,xi,yi+=2*(redTime-yellowTime));
               gp.setColor(Color.yellow);
               gp.drawLine(xi,yi,xi,yi+=2*(yellowTime-greenTime));
               gp.setColor(Color.green);
               gp.drawLine(xi,yi,xi,yi+=2*greenTime);
            }
         //}
         xi+=width+roadWidth;
      }
      gp.setColor(c);
   }
   
   void setupDelay(int id,int Time){
      for(int i=id;i+=Time;
      //drawTiming(running);
   }

   public int height(){ return height;}

   boolean setStatus(long t){
      boolean out=false;
      long dt;
      int s,ts;
      for(int i=0;i         s=status;
         dt=(t-delayArray) % redTime;
         if(dt<0)dt+=redTime;
         if(dt            status=green;
            ts=greenTime-(int)dt;
         }else if(dt            status=yellow;
            ts=yellowTime-(int)dt;
         }else{
            status=red;
            ts=redTime-(int)dt;
         }
         if(s!=status){
            out=true;
         }
            drawLight(i,ts);
      }
      return out;
   }
}

class numberInput {
   int width,height,xs,ys,x,y;
   String title;
   Graphics g;
   int value=0;
   double scale=1.;
   Rectangle add,sub;
   int change=0;
   boolean bounded=false;
   int min=0,max=100;
   int xwidth=60;
   numberInput(Graphics gs,int xi,int yi,String s,boolean rightAlign){
      g=gs;x=xi;y=yi;title=s;
      FontMetrics fm=g.getFontMetrics();
      if(rightAlign)x-=xwidth;//fm.stringWidth(title);
      init();
   }
   numberInput(Graphics gs,int xi,int yi,String s){
      g=gs;x=xi;y=yi;title=s;
      init();
   }
   void init(){
      FontMetrics fm=g.getFontMetrics();
      int h=fm.getHeight(),w=xwidth;//fm.stringWidth(title);
      int h2=h/2;
      width=w-h-2;
      height=h;
      int yy=y+h;
      g.drawString(title,x,yy);
      yy+=1;
      int xa[]={x,x+h2,x+h2},xb[]={x+w,x+w-h2,x+w-h2};
      int yab[]={yy+h2,yy,yy+h};
      xs=x+h2+3;
      ys=yy+h-2;
      g.drawRect(xs-2,ys-height+2,width-1,height);
      g.fillPolygon(xa,yab,3);
      g.fillPolygon(xb,yab,3);
      sub=new Rectangle(x,y+h+1,h2,h);
      add=new Rectangle(x+w-h2,y+h+1,h2,h);
      setValue(0);
   }
   void setValue(int i,int mi,int mx){
      setValue(i);
      bounded=true;
      min=mi;
      max=mx;
   }
   void setValue(int i,int s){
      scale=10^s;
      setValue(i);
   }
   
   void setValue(int i){
      value=i;
      g.clearRect(xs-2+1,ys-height+3,width-3,height-2);
      Color c=g.getColor();;
      g.setColor(Color.black);
      g.drawString(String.valueOf(i*scale),xs,ys);
      g.setColor(c);
   }
   boolean valueChange(int di){
      if(bounded &&( (value==min && di<0) || (value==max && di>0)))di=0;
      if(di==0)return false;
      value+=change;
      setValue(value);
      return true;
   }
   int lastChange(){ return change;}
   double value(){ return scale*value;}

   public boolean mouseDown(Event e, int x, int y){
      if(add.inside(x,y))change=1;
      else if(sub.inside(x,y))change=-1;
      else change=0;
      return valueChange(change);
   }
}

class Traffic {//implements Runnable{
   // traffic control center
   Vector v=new Vector(); // main traffic
   Vector v2[]; // other traffics
   car c;
   int w=10,h=5,y0,w2=w/2;
   Graphics g;
   static double a=10.;
   static private double a2=a/6.;
   int minDx=3,xMax,Dx,Dx2,minDx2;
   Light L;
   int passed=0,passed2=0;
   int ymax,ymin,y1;
   Traffic(Light Li){
      L=Li;
      v2=new Vector[L.count];
      for(int i=0;i=new Vector();
   }

   double roadWidth=15.;
   void init(Graphics gs,int x,int y,int xmax){
      passed=0;
      passed2=0;
      a2=a/6.;
      g=gs;
      xMax=xmax+w+minDx;
      y0=y;
      Dx=w+minDx;
      Dx2=Dx+minDx;
      minDx2=2*minDx;
      reset();
      v.removeAllElements();
      for(int i=0;x>0;i++,x-=Dx){
         c=new car((double)(x),0.,0.);
         if(i==0)c.setFront(true);
         else c.setFront(false);
         v.addElement(c);
         drawCar(c,false);
      }
      // for vertical cars
      ymax=y0+L.height();
      ymin=y0-(int)roadWidth-L.height();
      for(int i=0;i         v2.removeAllElements();
         int sign=1-2*(i%2);
         int n=L.height()/Dx;
         y1=y0-(int)roadWidth;
         for(int j=0;j            c=new car(y1-j*Dx,0.,0.);
            if(j==0)c.setFront(true);
               else c.setFront(false);
            v2.addElement(c);
            drawCar(c,L.X,sign,false);
         }
      }
      // draw car color code
      int xx=15,yy=ymin+15,xx2=xx+w+h;
      g.setColor(Color.black);
      g.drawRect(xx,yy,w,h);
      g.drawString("a>0.",xx2,yy+h);
      g.setColor(Color.yellow);
      g.fillRect(xx,yy,w,h);
      yy+=w;
      g.setColor(Color.black);
      g.drawRect(xx,yy,w,h);
      g.drawString("a=0.",xx2,yy+h);
      g.setColor(Color.green);
      g.fillRect(xx,yy,w,h);
      yy+=w;
      g.setColor(Color.black);
      g.drawRect(xx,yy,w,h);
      g.drawString("a<0.",xx2,yy+h);
      g.setColor(Color.red);
      g.fillRect(xx,yy,w,h);
      g.setColor(Color.black);
   }

   void reset(){
      g.clearRect(0,y0-h,xMax,h+1);
   }
   void drawCar(car c,int x,int sign,boolean erase){
         int xx=x+w2,yy=(int)c.y[0]-w2;
         if(sign==-1)yy=ymin+ymax-yy;
         if(erase)g.clearRect(xx,yy,h+1,w+1);
         else {
            g.drawRect(xx,yy,h,w);
            Color color=g.getColor();
            if(c.acceleration==0.)g.setColor(Color.green);
            else if(c.acceleration<0)g.setColor(Color.red);
            else g.setColor(Color.yellow);
            g.fillRect(xx,yy,h,w);
            g.setColor(color);
         }
   }

   void drawCar(car c,boolean erase){
         if(erase)g.clearRect((int)c.y[0]-w,y0-h,w+1,h+1);
         else {
            g.drawRect((int)c.y[0]-w,y0-h,w,h);
            Color color=g.getColor();
            if(c.acceleration==0.)g.setColor(Color.green);
            else if(c.acceleration<0)g.setColor(Color.red);
            else g.setColor(Color.yellow);
            g.fillRect((int)c.y[0]-w,y0-h,w,h);
            g.setColor(color);
         }
   }
   // traffic flow control
   car cs;
   boolean nextFront;
   void advanced(double dt){
      cs=null;
      c=(car)v.firstElement();
      c.setAcceleration(a);
      if(c.y[0]>xMax){// remove car outside boundary
         v.removeElement(c);
         passed+=1;
         drawCar(c,true);
         c=null;
      }
      nextFront=false;
      int count2=L.count;
      double aNeeded,tReact=1.;
      double minD=Dx*1.2,safeD=2.*Dx;
      for(Enumeration e=v.elements();e.hasMoreElements(){
         c=(car)e.nextElement();
         if(c.lightID            if(cs!=null){
               minD=cs.y[0]-c.y[0]-Dx;
               safeD=minD-c.y[1]*tReact;
               if(minD<0.)c.y[1]=cs.y[1];// too close
            }else{
               minD=Dx;
               safeD=2.*Dx;
            }
            if((cs!=null)&& safeD<0.){ // be safe
                     aNeeded=2.*(cs.y[1]*cs.y[1]-c.y[1]*c.y[1])/minD;//(cs.y[0]-c.y[0]-Dx);
                     //aNeeded=a;
                     c.setAcceleration(aNeeded);
            }else{
               switch(L.status[c.lightID]){
               case 0: // green light
                  if(cs!=null && minD>2.*minDx)c.setAcceleration(a);
               break;
               case 1: //yellow
                  if(L.X[c.lightID]-c.y[0] < c.y[1]*c.y[1]/(3.*Math.max(a,10.)))break;
               case 2:
                  if(c.isFront()){
                     if(L.X[c.lightID]-c.y[0] > 2.*Dx2)
                        c.setAcceleration(a);
                     else if(L.X[c.lightID]-c.y[0] < minDx){
                        c.y[1]=0.;
                        c.setAcceleration(0.);
                     }else {
                        aNeeded=c.y[1]*c.y[1]/(L.X[c.lightID]-c.y[0]);
                        c.setAcceleration(-aNeeded);
                     }
                  }else if(cs!=null){
                     if(safeD > Dx2)c.setAcceleration(a);
                     else if(cs.acceleration<0. && c.acceleration>0.){
                        aNeeded=(cs.y[1]*cs.y[1]-c.y[1]*c.y[1])/minDx;//(cs.y[0]-c.y[0]);
                        c.setAcceleration(aNeeded);
                     }else c.setAcceleration(0.);
                  }
                  break;
               }
            }
            if(c.y[0]>=L.X[c.lightID]){
               c.lightID+=1; //just pass one traffic light
               nextFront=true;
            }else if((c.y[0]                  c.setFront(true);
                  nextFront=false;
            }

         } else c.setAcceleration(a);

         // advanced one time step
         //drawCar(c,true);
         c.advanced(dt);
         drawCar(c,false);
         cs=c;
      }
      if((int)c.y[0]>Dx){
         v.addElement(new car(0.,0.,a));
         drawCar(c,false);
      }
      advanced2(dt);
   }

   void advanced2(double dt){
      // if passed lighID=1;
      int sign;
      for(int i=0;i         c=(car)v2.firstElement();
         cs=null;
         sign=1-2*(i%2);
         if(c.y[0]>ymax){
            v2.removeElement(c);
            passed2+=1;
            drawCar(c,L.X,sign,true);
            c=null;
         }
         nextFront=false;
         for(Enumeration e=v2.elements();e.hasMoreElements(){
            c=(car)e.nextElement();
            if(c.lightID==0){// not pass light yet
               if(c.y[0]<=y1){
                  if(nextFront){
                     c.setFront(true);
                     nextFront=false;
                  }
               }else{
                  c.lightID+=1; //just pass one traffic light
                  c.setAcceleration(a);// keep accelerating
                  nextFront=true;
                  if(cs!=null)c.setFront(false); // first car, always front
               }
               double aNeeded=a;
               if(L.status==2){ // red light, green for us
                  if(cs==null)c.setAcceleration(a);
                  else if((cs.y[0]-c.y[0]) > Dx2 )
                     c.setAcceleration(a);
               }else { // green or yellow light, red for us
                  if(c.isFront()){
                     if(y1-c.y[0] < minDx){
                        c.y[1]=0.;
                        c.setAcceleration(0);
                     }else{
                        aNeeded=c.y[1]*c.y[1]/(y1-c.y[0]);
                        c.setAcceleration(-aNeeded);
                     }
                  }else if(cs!=null){
                     if(cs.y[0]-c.y[0] > Dx2)
                        c.setAcceleration(a);
                     else if(cs.y[0]-c.y[0] < Dx){
                           c.y[1]=cs.y[1];
                           c.setAcceleration(0.);
                     }else if(cs.acceleration<=0.){
                        aNeeded=(cs.y[1]*cs.y[1]-c.y[1]*c.y[1])/(cs.y[0]-c.y[0]);
                        c.setAcceleration(aNeeded);
                     }
                  }
               }
               if( (cs!=null)  && (cs.y[0]-c.y[0] < Dx) ){
                  c.y[1]=0.;
               }
         }

            // advanced one time step
            //drawCar(c,L.X,sign,true);
            c.advanced(dt);
            drawCar(c,L.X,sign,false);
            cs=c;
         }
         if((int)c.y[0]>ymin+Dx){
            v2.addElement(new car(ymin,0.,a2));
            drawCar(c,L.X,sign,false);
         }
      }
   }
   void drawVelocity(Graphics g0){
      int size=2,size2=4;
      int xoffset=-w2-size,yoffset=y0-(int)roadWidth-size+h;
      g0.setColor(Color.blue);
      for(Enumeration e=v.elements();e.hasMoreElements(){
         c=(car)e.nextElement();
         g0.fillOval((int)c.y[0]+xoffset,yoffset-(int)(2.*c.y[1]),
            size2,size2);
      }
   }
}

class car extends rk4 {
   double acceleration=10.;
   static double vmax=30.,vmin=0.,vMove=3.;
   double xmax=100.;
   int lightID;
   boolean front=false;

   car(double xi,double vi,double ai){
      init(2,true);
      y[0]=xi;
      y[1]=vi;
      acceleration=ai;
      lightID=0;
   }

   void setAcceleration(double ai){
      acceleration=ai;
   }
   boolean isFront(){return front;}
   void setFront(boolean f){
      front=f;
   }
   void advanced(double dt){
      nextmove(dt);
      if(y[1]         acceleration=0.;
         y[1]=0.;
      }else if(y[1]>vmax){
         acceleration=0.;
         y[1]=vmax;
      }
   }
   public void derivs (double t,double y[],double dydx[]){
      dydx[0]=y[1]; // V_theta
      dydx[1]=acceleration; // alpha=-K theta
   }
}

// RK4
abstract class rk4 {
   int n;
   public double dydx[];
   public double y[],yout[];
   public void init(int dim,boolean self){
      n=dim;
      dydx=new double[n];
      yout=new double[n];
      if(self)y=yout;
         else   y=new double[n];
   }

    public abstract void derivs(double x,double y1[],double dydx[]);
   /*                                                                                                
   public void next(double x,double h){ // t & dt
      core(x,h);
   }
   public double[]  next(double h){ // dt
      core(0.,h);
      return yout;
   }*/
   public void nextmove(double h,double[] yin){
      y=yin;
      core(0.,h);
   }
   public void nextmove(double h){
      core(0.,h);
   }
   private void core(double x, double h){
   /* Runge-Kutta forth-order method */
      int i;
      double xh,hh,h6;
      double dym[]=new double[n];
      double dyt[]=new double[n];
      double yt[]=new double[n];
      hh=h*0.5;
      h6=h/6.0;
      xh=x+hh;
      derivs(xh,y,dydx);
      for (i=0;i=y+hh*dydx;
      derivs(xh,yt,dyt);
      for (i=0;i=y+hh*dyt;
      derivs(xh,yt,dym);
      for (i=0;i         yt=y+h*dym;
         dym += dyt;
      }
      derivs(x+h,yt,dyt);
      for (i=0;i         yout=y+h6*(dydx+dyt+2.0*dym);
   }
}

[laramsf]

Hello..
I know I am stupid Beginner in java, you can put more comments with the code?(Please)
To help me a lot to understand.

Thank you very much...

[laramsf]

?

[Fu-Kwun Hwang]

The traffic control  code was created 17 years ago. I needed to draw all the view element with java code by myself.
I started to use EJS since 2001.  With EJS: I only need to define variables, provide initial value, relation between variables , set up properties for graphical user interface elements.  Then, EJS will generate java code and create the program.
e.g.    Ejs version of traffic control simulation
So I did not wrote java code for 12 years. 

It will take me a lot of time to write extended comments.
If you can indicate where you did not understand the code. I may be able to find time to check it out and figure out what the code is about.
Is it the physics you did not understand? Is it the numerical method you did not understand? Is it the view elements you did not understand?

[mazen]

hi sir...
  I'm a college student, I have a graduation project, I loved this simulation, and I want to implement.
First:
- Install the Java JDK.
- Opened file TrafficControl with the textpad and saved the file to  TrafficControl.java
(But I can't find implementation"RUN"). Are my steps correct? What are the right steps?

Second:
How can I work extra opposite direction of the vector cars from left to right?
Please help.

Thank you

[mazen]

hi sir...
  I'm a college student, I have a graduation project, I loved this simulation, and I want to implement.
First:

When i compile the source code gave me an error 100, mostly in the for loop?I did not know to deal with?
Can you solve this problem?

How can I work extra opposite direction of the vector cars from left to right?
Please help.

Thank you

[Fu-Kwun Hwang]

The simulation at the top of this topic was created 17 years ago with JDK1.0.2

You might need to change some of the code for latest JDK.

However, you can compile it with JDK1.0.2 without error message.
JDK102.zip is added as attached file. You can download it and use it to compile the above code.


There is another  Ejs version of traffic control simulation
You can view how it was created and add new condition if you install EJS.
You can find ejs download link with google search:EJＳ download.

 

[mazen]

Sorry for the inconvenience sir, really.
How can i compile it with JDK1.0.2? i download it.
But
i think their error in my system because the winrar give me 3 error

secondly:
How do I use the ejs in thهis subject because I deal with it in the first time?

[Fu-Kwun Hwang]

Download jdk102.zip
unzip it to root

jdk102\bin\javac.exe your_java_code.java

Download EJS from the web site
unzip it
Click ejsConsole.jar to initial the preperties (only need to be done once).
Close it.

Download TrafficControl.jar from EJS version trafficControl web page
Double click it to run the jar file.
Click right mouse button in the java window. Select open EJS model,
And you will find all the code in the EJS environment.

You can learn more about EJS from EJS web site.

[louse]

your code for traffic signal light is so great -*-

[mazen]

Hello sir ..

I hope that you have the knowledge and the source code for the design of an compiler in C + +? With writing comments ..

Thank you

[jimmyjjohn]

Hello Dear!

I am on here wondering if anyone reading this know where I can find a website that will teach me how to read a caliper. I need to learn this for a job I am applying for.

Thanks-*-

[Fu-Kwun Hwang]

If you want to know how to read a cliper.
Please check out the following URL
http://www.phy.ntnu.edu.tw/ntnujava/viewtopic.php?t=69

[Charli05]

The traffic light system contain have 3 light red yellow and green and these are the sign of your safety..