r> <tr><td><code>stack</code></td> <td><code>string</code></td> <td></td> <td>Stack group. Axes at the same <code>position</code> with same <code>stack</code> are stacked.</td></tr> <tr><td><code>stackWeight</code></td> <td><code>number</code></td> <td>1</td> <td>Weight of the scale in stack group. Used to determine the amount of allocated space for the scale within the group.</td></tr> <tr><td><code>axis</code></td> <td><code>string</code></td> <td></td> <td>Which type of axis this is. Possible values are: