//画正弦曲线程序

import java.applet. *;
import java.awt.*;
import java.awt.event.*;
public class ko12_3 extends applet implements actionlistener
{
int x,y;
double a;
button bn1=new button("sin波形");
button bn2=new button("清除");
public void init()
{
add(bn1);
add(bn2);
bn1.addactionlistener(this);
bn2.addactionlistener(this);
}
public void actionperformed(actionevent e)
{
graphics g=getgraphics();
if(e.getsource()==bn1)
{
for(x=0;x<=360;x+=9)
{
a=math.sin(x*math. pi/180);
y=(int)(80+40*a);
g.drawstring("*",x,y);
}
}
if(e.getsource()==bn2)
repaint();
}
}
//ko12_3.html
<applet code="ko12.3class"width=280 height=160>
</applet>