心型applet

import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;

public class CartesianCurve extends Applet{
   int width, height;
   Image image;
   Graphics draw_Curve;
   public void init(){
 setBackground(Color.black);
 this.setSize(350, 310);
 width = getSize().width;
 height = getSize().height;
 image = createImage(width, height);
 draw_Curve = image.getGraphics();
   }
   public void paint(Graphics g){
 draw_Curve.clearRect(0, 0, width, height);
 draw_Curve.setColor(Color.green);
 int i, j;
 double x, y, r;
 for(i = 0; i <= 90; i++)
 for(j = 0; j  <= 90; j++){
 r = Math.PI / 45 * i * (1 - Math.sin(Math.PI / 45 * j)) * 18;
 x = r * Math.cos(Math.PI / 45 * j) * Math.sin(Math.PI / 45 * i) + width / 2;
 y = -r * Math.sin(Math.PI / 45 * j) + height / 4;
 draw_Curve.fillOval((int) x, (int)y, 2, 2);
 }
 g.drawImage(image, 0, 0, this);
   }
   }