double[] x=new double[num];
double[] xx=new double[num];

	private int num=500; // Number of red balls.
	private int numBig=100; // Number of red balls.
	boolean frozen=false; // Whether the simulation is stopped.
	private Graphics offscreen; // Offscreen buffer for double-buffering.
	Image offImage;
	Scope myScope; // Reference to the microscope view of this ball.
	Dimension thisSize; // Size of canvas.
	Thread animatorThread; // The thread of multi-threaded.
	// Because the balls live on a torus (wrap-around boundary conditions),
	// they can strike the blue particle on any side of the playing field.
	// offsets[][] carries the nine current locations of the blue ball.
	int[][] offsets;
	// Positions (x,y) and velocities (xx,yy) of all red balls.
	// Positions (bigx,bigy) and velocities (bigxvel,bigyvel) of all blue balls.
	double[] x=new double[num];
	double[] xx=new double[num];
	double[] y=new double[num];
	double[] yy=new double[num];

	double[] bigxvel=new double[numBig];
	double[] bigyvel=new double[numBig];
	double[] bigx=new double[numBig];
	double[] bigy=new double[numBig];

	public void init()
	{
	String sParam;
		int nBalls, nBigBalls;
		double dMassRatio, dAverageVelocity;
		ResourceBundle rb;

		// The resource bundle contains strings in various languages.
		// See the CollisionStrings*.properties files.
		String sUseRB = this.getParameter("international");
		rb = null;
		if ((sUseRB == null) || !sUseRB.equalsIgnoreCase("no")) {
			String sLang = this.getParameter("language");
			String sCountry = this.getParameter("country");
			try {
				if (sLang == null)
					rb = ResourceBundle.getBundle(sResource, Locale.getDefault());
				else {
					Locale thisloc;
					if (sCountry == null)
						thisloc = new Locale(sLang,"");
					else
						thisloc = new Locale(sLang,sCountry);
					rb = ResourceBundle.getBundle(sResource,thisloc);
				}
			} catch (java.lang.ClassFormatError e) {
				System.out.println("ClassFormatError: "+e.getMessage());
				rb = null;
			} catch (MissingResourceException e) {
				System.out.println("Missing Resource: "+e.getMessage());
				rb = null;
			}
		}
		if (rb!=null) {
			try {
				sStart = rb.getString("start");
				sStop = rb.getString("stop");
				sReset = rb.getString("reset");
			} catch (MissingResourceException e) {
				System.out.println("Missing Resource: "+e.getMessage());
				sStart = "Start";
				sStop = "Stop";
				sReset = "Reset";
			}
		} else {
			sStart = "Start";
			sStop = "Stop";
			sReset = "Reset";
		}
		// Load parameters needed for creating the main panel.
		sParam = this.getParameter("nballs");
		if (sParam != null) {
			try {
				nBalls = Integer.parseInt(sParam);
			} catch (NumberFormatException e) {
				nBalls = 40;
				System.out.println("nballs should be an integer number of balls in the box.");
			}
		} else nBalls = 110;
		sParam = this.getParameter("nBigballs");
		if (sParam != null) {
			try {
				nBigBalls = Integer.parseInt(sParam);
			} catch (NumberFormatException e) {
				nBigBalls = 40;
				System.out.println("nBigballs should be an integer number of balls in the box.");
			}
		} else nBigBalls = 10;