flot画曲线坐标

源代码：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>深海的小鱼编制-PLOT</title>
<script language="javascript"  type="text/javascript" src="jquery.js"></script>
<script language="javascript" type="text/javascript" src="jquery.flot.js"></script>
<style type="text/css">
#apDiv1 {
    position:absolute;
    600px;
    height:300px;
    z-index:1;
    left: 200px;
    top: 167px;
}
</style>
</head>

<body>
<h1>深海的小鱼儿-正弦和余弦函数图像</h1> 
<div id="apDiv1" align="center"></div>
<script type="text/javascript">
$(function(){
    var sin = [];
    for(var i=0;i<Math.PI*2;i+=0.25)
        sin.push([i,Math.sin(i)]);
        
    var cos = [];
    for(var i=0;i<Math.PI*2;i+=0.25)
        cos.push([i,Math.cos(i)]);
    
    $.plot($("#apDiv1"),[
                        {label:"正弦函数",data:sin},
                        {label:"余弦函数",data:cos}
                        ],{
                           series:{
                              lines:{show:true},
                              points:{show:true}
                                  },
                           xaxis: {
                              ticks: [0, [Math.PI/2, "\u03c0/2"], [Math.PI, "\u03c0"],
                                     [Math.PI * 3/2, "3\u03c0/2"], [Math.PI * 2, "2\u03c0"]]
                                   },
                          yaxis: { ticks: 6,min: -1.2,max: 1.2},
                          grid: {
                            backgroundColor: 
                            { colors: ["#789", "#eee"] }
        }
                          }                                                            
          );
});    
</script>
</body>
</html>