title: d3.js Plot elements using polar coordinates
body: <p>I am new to d3.js and not sure which d3 functionality to use.</p>
  
  <p>I need to place a set of elements concentrically about an origin (in a circle).</p>
  
  <pre><code>svg.selectAll('circle').each(function() {
      d3.select(this)
          .attr('cx', r * Math.cos(theta))
          .attr('cy', r * Math.sin(theta));
      theta += thetaInc;
  });
  </code></pre>
  
  <p>So instead of doing something tedious like the above code, what is the d3 short way of doing this?</p>