javascript – 在d3.js中制作一个弧

我正在使用 javascript库d3.js( http://d3js.org/)来创建画布数据可视化.我试图做一个弧,但它不接受数组中的数据参数.有人知道我在做错什么吗？这是我的代码：

var chartConfig = { "canvasSize" : 800 }

var radius = chartConfig.canvasSize / 2;
var pi = Math.PI;

var vis = d3.SELEct("#chart").append("svg")
    .attr("width",radius * 2)
    .attr("height",radius * 2)
    .append("g")
    .attr("transform","translate(" + radius + "," + radius + ")");

var arcData = [
  {aS: 0,aE: 45,rI:radius/2,rO:radius}
];
var arc = vis.SELEctAll("arc").data(arcData).enter().append("arc");
arc.attr("innerRadius",function(d){d.rI}).attr("outerRadius",function(d){d.rO}).attr("class","arc");

function degToRad(degrees){
  return degrees * (pi/180);
}

var arc = d3.svg.arc()
    .innerRadius(50)
    .outerRadius(70)
    .startAngle(45 * (Math.PI/180)) //converTing from degs to radians
    .endAngle(3) //just radians

vis.append("path")
    .attr("d",arC)
    .attr("transform","translate(200,200)")