效果：
源码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>坐标系绘制</title>
</head>
<body>
<canvas id="canvas"></canvas>
<script>
(function () {
//canvas布局
var canvas = document.getElementById("canvas");
canvas.width = 600;
canvas.height = 600;
canvas.style.border = "1px solid red";
//获取上下文
var ctx = canvas.getContext("2d"); //绘制坐标轴
var x0 = 100,y0 = 500;// xy轴原点
var maxX = 500,maxY = 100;
var lineWidth = 10;//箭头宽度
//x轴
ctx.beginPath();
ctx.moveTo(x0,y0);
ctx.lineTo(maxX,y0);
ctx.lineTo(maxX-lineWidth,y0+lineWidth);
ctx.moveTo(maxX,y0);
ctx.lineTo(maxX-lineWidth,y0-lineWidth);
ctx.stroke();
//y轴
ctx.beginPath();
ctx.moveTo(x0,y0);
ctx.lineTo(x0,maxY);
ctx.lineTo(x0-lineWidth,maxY+lineWidth);
ctx.lineTo(x0,maxY);
ctx.lineTo(x0+lineWidth,maxY+lineWidth);
ctx.stroke(); //折线
var data = [.5,.4,.6,.8,.7,.9,.3];
var xWidht = 400/(data.length+1);//x轴间距
ctx.beginPath();
for(var i = 0;i<data.length;i++){
ctx.lineTo(100+xWidht*(i+1),500-400*data[i]);
}
ctx.strokeStyle = 'blue';
ctx.stroke(); }())
</script>
</body>
</html>