arc with datum by lindep

index.html

<!DOCTYPE html>
  <head>
    <meta charset="utf-8">
    <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
    <style>
      body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
      svg { width: 100%; height: 100%; }
    </style>
  </head>

  <body>  
    <script>
      var margin = {top: 20, right: 10, bottom: 20, left: 17};
      var width = 640 - margin.left - margin.right;
      var height = 500 - margin.top - margin.bottom;
      var svg = d3.select("body").append("svg")
        .attr("width", width + margin.left + margin.right)
        .attr("height", height + margin.top + margin.bottom);
      
      svg.append("g")
        .attr("class","myclass")
        .attr("transform", "translate(" + margin.left + "," + margin.top + ")");
		
      var x=295,y=254;
      var rad=137;
      var angle=45;
      var data = {x:100,y:100,a:angle}
      function drawArc(container,data) {
        
      }
      var arc=d3.svg.arc()
        .innerRadius(0)
        .outerRadius(rad)
        .startAngle((angle-18)*(Math.PI/180))
        .endAngle((angle+18)*(Math.PI/180));
			//console.log(arc.centroid());
      
			var group = d3.selectAll('g.myclass')
      	.datum(data)
        .append('svg:g')
      	.attr("class","siteClass");
      
      group.append('path')
      	.attr('d',arc)
        .attr("transform", "translate("+x+","+y+")")
        .attr('fill','red')
        .attr('strokeWidth',1);

    </script>
  </body>