
  var scatter = d3.select(".chart").selectAll("circle")
      .data(data);
    
  //ENTER
  var enter = scatter.enter().append("circle")
      .attr("fill-opacity",0.85)
      .attr("r",5)
      .attr("stroke-width","0px");
  
  // Add a title to the point (on mouseover)
  enter.append("svg:title")
      .text(function(d){ return d.name; });
    
  //ENTER + UPDATE
  enter.merge(scatter)
      .attr("cx",function(d,i){ return (380*i/sampleData.length)+ 60; })
      .attr("cy",function(d){ return 465-((d.ag