 a hex-string is used as the
colour, this argument is ignored and you should include the alpha on the hex string</p></td>
    </tr>
    <tr>
      <th>stroke_width</th>
      <td><p>width of the stroke in pixels</p></td>
    </tr>
    <tr>
      <th>frequency</th>
      <td><p>column of <code>data</code>, or a single value indicating the number of
arcs generated in each animation</p></td>
    </tr>
    <tr>
      <th>animation_speed</th>
      <td><p>the speed of animation</p></td>
    </tr>
    <tr>
      