title: Get an array of points from D3 line()
body: <p><code>d3.line(data)</code> returns a path data string. But, If I understand correctly, <code>d3.line(data).context(context)</code> draws directly the line on the canvas.
  How can I get the <strong>array of points</strong> used to draw the line on the canvas?</p>
  
  <p>And, is it possible to change the preciseness of the line resulting from <code>d3.line().curve()</code> by passing the number of desired points?</p>
  
  <p>Here is what I want to achieve:</p>
  
  <pre><code>makeACurvedLine([p1, p2, p3], 6)
  </code></pre>
  
  <p>And get the array of coordinates of the 6 points from the smoothed line.</p>
  
  <p>What is the best way to achieve it?</p>