title: Using "attr" vs. "animate" to change Raphael object using node ID
body: <p>I'm building an application that uses Raphael to draw circles on a map based on values read from a json feed. Each circle node gets an ID, which I then use to call it and change its attributes. Selecting a new variable changes the size and color of the circles. I can change the size using JQuery's attr method, but not animate.</p>
  
  <p>I've assigned an ID to each circle:</p>
  
  <pre><code>circle.raphael.node.id = [thisCircle]
  </code></pre>
  
  <p>I can change the size and color of each circle using the attribute method, thusly:</p>
  
  <pre><code>$(thisCircle).attr({
  r : [new radius]
  fill : [new color]
  });
  </code></pre>
  
  <p>But I can't animate it using JQuery's animate method:</p>
  
  <pre><code>$(thisCircle).animate({
  r : [new radius],
  fill : [new color]
  }, 200);
  </code></pre>
  
  <p>What am I missing? </p>