ss="block">Calculates the radius of a node.</div>
<dl><dt><span class="strong">Parameters:</span></dt><dd><code>start</code> - The start index of the portion in indices array 
 that belongs to the node.</dd><dd><code>end</code> - The end index of the portion in indices array 
 that belongs to the node.</dd><dd><code>instList</code> - The indices array holding indices of 
 instances.</dd><dd><code>insts</code> - The actual instances. instList points to 
 instances in this object.</dd><dd><code>pivot</code> -