title: Graph ending in mathbox.js
body: <p>I'm trying to learn some mathbox.js basics, let's say the domumentation is not the worst, but it lacks a lot of info. Now, my problem is this:</p>
  
  <p>I'm trying to draw a circle in a cartesian view, so I wrote:</p>
  
  <pre><code> var data =
    view.interval({
    expr: function (emit, x, i, t) {
      emit(x, Math.sqrt(4 - (x*x)));
      emit(x, -Math.sqrt(4 - (x*x)));
  
    },
    length: 1024,
    channels: 2,
    items: 2,
  });
  
  var curve =
  view.line({
  width: 4,
  color: '#3090FF',
    zIndex: 2,
    });
  </code></pre>
  
  <p>But it gives me this:</p>
  
  <p><img src="https://i.stack.imgur.com/NIFg0.png" alt=""></p>
  
  <p>I have no idea why, I have tried setting all the possible parameters of the line, but it keeps the same(or disappears)</p>
  
  <p>What can I do so the end of the lines merge?</p>