import awb.*;
import java.awt.*;
import java.awt.event.*;

public class CylinderVolumeMax extends java.applet.Applet 
		implements ActionListener
{
    double r, previousV, increase, V;
    DoubleField rF, increaseF, VF;
    Button b1;
    public void init ()
    {
	rF = new DoubleField(20);
	rF.setLabel("Radius");
	increaseF = new DoubleField(20);
	increaseF.setLabel("increase");
	b1 = new Button("Compute");
	b1.addActionListener(this);
	VF = new DoubleField(20);
	VF.setLabel("Best Volume");
	add(rF);
	add(increaseF);
	add(b1);
	add(VF);
	rF.setDouble(1.0);
	increaseF.setDouble(0.01);
    }

    public void actionPerformed(ActionEvent event)
    {	
	Object cause = event.getSource();
	if (cause == b1)
	{
	    r = rF.getDouble();
	    increase = increaseF.getDouble();
	    previousV = 0;
	    V = 500 * r - 3.14159 * r * r * r;
	    while (V >= previousV)
	    {
	         r = r + increase;
	         previousV = V;
	         V = 500 * r - 3.14159 * r * r * r;
	    }
	    VF.setDouble(previousV);
	    r = r - increase;
            rF.setDouble(r);
	}
    }
}