title: Javascript library d3 call function
body: <p>I am not able to understand how d3.call() works and when and where to use that. <a href="http://alignedleft.com/tutorials/d3/axes/" rel="noreferrer">Here</a> is the tutorial link that I'm trying to complete.</p>
  
  <p>Can someone please explain specifically what this piece is doing</p>
  
  <pre><code>var xAxis = d3.svg.axis()
                .scale(xScale)
                .orient("bottom");
  
  svg.append("g").call(xAxis);
  </code></pre>