text: var vis = d3.select("body").append("svg")
  var pi = Math.PI;
      
  var arc = d3.svg.arc()
      .innerRadius(65)
      .outerRadius(70)
      .startAngle(45 * (pi/180)) //converting from degs to radians
      .endAngle(45) //just radians
      
  var arc2 = d3.svg.arc()
      .innerRadius(75)
      .outerRadius(80)
      .startAngle(45 * (pi/180)) //converting from degs to radians
      .endAngle(45) //just radians
      
  vis.attr("width", "2000").attr("height", "2000") // Added height and width so arc is visible
      .append("path")
      .attr("d", arc)
      .attr("fill", "black")
      .attr("transform", "translate(200,200)")    
      .on("click", function (d, i){
          d3.select(this)
          .attr("d", arc2)
          .attr("fill", "black")
  
      });
  
  vis.attr("width", "2000").attr("height", "2000") // Added height and width so arc is visible
      .append("path")
      .attr("d", arc)
      .attr("fill", "black")
      .attr("transform", "translate(70,70)")    
      .on("click", function (d, i){
          d3.select(this)
          .attr("d", arc2)
          .attr("fill", "black")
  
      });
      
  vis.attr("width", "2000").attr("height", "2000") // Added height and width so arc is visible
      .append("path")
      .attr("d", arc)
      .attr("fill", "black")
      .attr("transform", "translate(70,300)")    
      .on("click", function (d, i){
          d3.select(this)
          .attr("d", arc2)
          .attr("fill", "black")
  
      });
  
  vis.attr("width", "2000").attr("height", "2000") // Added height and width so arc is visible
      .append("path")
      .attr("d", arc)
      .attr("fill", "black")
      .attr("transform", "translate(300,70)")    
      .on("click", function (d, i){
          d3.select(this)
          .attr("d", arc2)
          .attr("fill", "black")
  
      });
      
  vis.attr("width", "2000").attr("height", "2000") // Added height and width so arc is visible
      .append("path")
      .attr("d", arc)
      .attr("fill", "black")
      .attr("transform", "translate(300,300)")    
      .on("click", function (d, i){
          d3.select(this)
          .attr("d", arc2)
          .attr("fill", "black")
  
      });
      
      
  
  var i = 65;
  var j = 70;
  
  setInterval(function() { //alert("Hello"); 
  
  var arc3 = d3.svg.arc()
      .innerRadius(i++)
      .outerRadius(j++)
      .startAngle(45 * (pi/180)) //converting from degs to radians
      .endAngle(45) //just radians
      
    d3.selectAll("path").attr("d", arc3);
    
    if(i==600){
    i = 65;
    j = 70;
    }
  }, 20);