写在前面：

　　editplus换成eclipse了

　　Sketchpad要钱，买不起

　　自己搞(rua)

by emeralddarkness

　　建立了一个平面直角坐标系

　　两个变元x，y，参数i

　　实现了以下功能：

　　　　调节窗口大小

　　　　放缩单位长度

　　　　改变原点位置

　　　　改变参数方程

　　离超过Sketchpad还有十万八千里路要走呃呃呃

　　运行效果：

1 static double ponyX(double i){
2 return 4*Math.sin(i);
3 }
4 static double ponyY(double i){
5 return 6*Math.cos(i);
6 }

1 static double ponyX(double i){
2 return 4/Math.cos(i);
3 }
4 static double ponyY(double i){
5 return 6*Math.tan(i);
6 }

1 static double ponyX(double i){
2 return i;
3 }
4 static double ponyY(double i){
5 return i*i-i*4+2;
6 }

1 static double ponyX(double i){
2 return i;
3 }
4 static double ponyY(double i){
5 return i*4+5;
6 }

1 static double ponyX(double i){
2 return 4*Math.sin(i)+2;
3 }
4 static double ponyY(double i){
5 return 4*Math.cos(i)+3;
6 }

　　还能画出来各种奇奇怪怪的图形，比如说胡子

代码如下：

1 import java.awt.*;
2 import java.awt.event.*;
3 import java.awt.Graphics;
4 import java.io.*;
5 import java.util.*;
6 import javax.swing.ImageIcon;
7 import javax.swing.JFrame;
8 import javax.swing.JPanel;
9
10 public class PonysAlgorithm extends JFrame
11 {
12 static int winX=800,winY=600;
13 static int ponyIE=30;
14 static int zeroX=winX/2,zeroY=winY/2;
15 static int ponyPrecision=100;
16
17 static double ponyX(double i){
18 return 4*Math.sin(i)+2;
19 }
20 static double ponyY(double i){
21 return 4*Math.cos(i)+3;
22 }
23
24 public static void main(String[] args) throws Exception
25 {
26 JFrame ponyFrame=new JFrame("Pony's Algorithm");
27 ponyFrame.setLayout(null);
28 JPanel ponyJPanel=new JPanel(){
29 public void paint(Graphics g){
30 super.paint(g);
31
32 g.setColor(Color.GRAY);
33 /*Coordinate Axis*/
34 g.drawLine(zeroX, 0, zeroX, winY);
35 g.drawLine(0, zeroY, winX, zeroY);
36
37 for(int i=zeroX+ponyIE;i<=winX;i+=ponyIE) 38 g.drawLine(i, zeroY-5, i, zeroY+5); 39 for(int i=zeroX-ponyIE;i>0;i-=ponyIE)
40 g.drawLine(i, zeroY-5, i, zeroY+5);
41 for(int i=winY+ponyIE;i<=winY;i+=ponyIE) 42 g.drawLine(zeroX-5, i, zeroX+5, i); 43 for(int i=winY-ponyIE;i>0;i-=ponyIE)
44 g.drawLine(zeroX-5, i, zeroX+5, i);
45
46 for(int i=1;zeroX+i*ponyIE0;--i)
49 g.drawString(""+i, zeroX+i*ponyIE-4, zeroY+20);
50 for(int i=1;zeroY+i*ponyIE0;--i)
53 g.drawString(""+(-i), zeroX-25, zeroY+i*ponyIE+4);
54
55 g.setColor(Color.BLACK);
56 /*CORE*/
57 int tmpa,tmpb;
58 for(int i=-10000;i<=10000;++i)
59 {
60 tmpa=(int)(ponyX(i/(double)ponyPrecision)*ponyIE)+zeroX;
61 tmpb=(int)(-ponyY(i/(double)ponyPrecision)*ponyIE)+zeroY;
62 g.drawLine(tmpa, tmpb, tmpa, tmpb);
63 }
64 }
65 };
66
67 /*Whole*/
68 ponyFrame.setSize(winX,winY);
69 ponyFrame.setResizable(false);
70 ponyFrame.setLocationRelativeTo(null);
71 ponyFrame.addWindowListener(new PonyWinAdapter());
72
73 /*ICON*/
74 File directory = new File("");
75 ponyFrame.setIconImage(Toolkit.getDefaultToolkit().getImage(directory.getCanonicalPath()+"\\icons\\32.png"));
76
77 /*DRAW*/
78 ponyJPanel.setBounds(2, 2, winX-10, winY-10);
79 ponyFrame.add(ponyJPanel);
80
81
82 ponyFrame.setVisible(true);
83 return;
84 }
85 }
86
87 class PonyWinAdapter extends WindowAdapter
88 {
89 public void windowClosing(WindowEvent windowEvent){
90 System.exit(0);
91 return;
92 }
93 }

附件：

*jar所在目录*\\icons\\

32.png