I am having problems with my piechart. I have everything that I am supposed to I think. It won't display in my JPanel. Could you please point me in the right direction.

Code:
					P = Q;//sets loop
						month++;
						//String showAmort = twoPlaces.format(H + C + Q);
						//amortScroll(showAmort);
	        			//ta.append("Month " + month);
	        			ta.append("Interest Paid: " + twoPlaces.format(H));
	        			ta.append("\tPrincipal Paid: " + twoPlaces.format(C));
	        			ta.append("\tNew Balance: " + twoPlaces.format(Q) + "\n");
					}

		}


		public void Calculations_manual() //performs the calculations from user input
		{

			double P = Double.parseDouble(PField.getText());
			double I = Double.parseDouble(IField.getText());
			double L = Double.parseDouble(LField.getText());
			double J = (I  / (12 * 100));//monthly interest rate
			double N = (L * 12);//term in months
			double M = (P * J) / (1 - Math.pow(1 + J, - N));//Monthly Payment
	        String showPayment = twoPlaces.format(M);
	        payment.setText(showPayment);



			int month = 1;

					while (month <= N)
					{

						//performs the calculations for the amortization
						double H = P * J;//current monthly interest
						double C = M - H;//monthly payment minus monthly interest
						double Q = P - C;//new balance
						P = Q;//sets loop
						month++;
						//String showAmort = twoPlaces.format(H + C + Q);
						//amortScroll(showAmort);
	        			//ta.append("Month " + month);
	        			ta.append("Interest Paid: " + twoPlaces.format(H));
	        			ta.append("\tPrincipal Paid: " + twoPlaces.format(C));
	        			ta.append("\tNew Balance: " + twoPlaces.format(Q) + "\n");

					}

		}

		// resets GUI for another calculation
		public void reset ()
		{
		PField.setText(null);
		payment.setText(null);
		ta.setText(null);
		LField.setText(null);
		IField.setText(null);
		}
		// ends GUI and exits program
		public void end()
		{
		System.exit(0);
		}

public class PieChart extends JComponent {

    // Class to hold a value for a slice
    class PieSlice
    {
        //private variables
        double value;
        Color color;

        public PieSlice(double value, Color color)
        {
            this.value = value;
            this.color = color;
        }//end Constructor

  	} //end class PieSlice


    //private variable slices are array of PieSlice
    PieSlice[] slices = new PieSlice[2];

    //constructor
    PieChart(double C, double H)
    {
        slices[0] = new PieSlice(C, Color.red);
        slices[1] = new PieSlice(H, Color.green);
        setVisible(true);
    }

    // This method is called whenever the contents needs to be painted
    public void paintComponent(Graphics g) {
        // Draw the pie
        this.drawPie((Graphics2D)g, getBounds(), slices);
    }

	// slices is an array of values that represent the size of each slice.
 	public void drawPie(Graphics2D g, Rectangle area, PieSlice[] slices)
 	{
 	        // Get total value of all slices
 	        double total = 0.0;
 	        for (int p=0; p<slices.length; p++) {
 	            total += slices[p].value;
 	        }

 	        // Draw each pie slice
 	        double curValue = 0.0;
 	        int startAngle = 0;
 	        for (int p=0; p<slices.length; p++)
 	        {
 	            // Compute the start and stop angles
 	            startAngle = (int)(curValue * 360 / total);
 	            int arcAngle = (int)(slices[p].value * 360 / total);

 	            // Ensure that rounding errors do not leave a gap between the first and last slice
 	            if (p == slices.length-1) {
 	                arcAngle = 360 - startAngle;
 	        } //end if

 	        // Set the color and draw a filled arc
 	        g.setColor(slices[p].color);
 	        g.fillArc(area.x, area.y, 200, 200, startAngle, arcAngle);
 	        RenderingHints renderHints = new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
			g.setRenderingHints(renderHints);
			//int border=10;
			//Ellipse2D.Double elb = new Ellipse2D.Double(area.x - border/2, area.y - border/2, pieWidth + border, pieHeight + border);


 	        //g.fillArc(area.x, area.y, area.width, area.height, startAngle, arcAngle);

 	        curValue += slices[p].value;
 	        } //end for
 	   }//end drawPie

        public void resetPieChart(double capital, double interest)
		{
					slices[0] = new PieSlice(capital, Color.red);
					slices[1] = new PieSlice(interest, Color.green);
					this.repaint();
		}//end resetPieChart
    }//end class PieChart

		public static void main(String[] args)
		{
			MortCalcWeek5p app = new MortCalcWeek5p();
			app.pack();



		}//end main

}//end the program
Thank you in advance for any help you may be.

Thanks,

Christine