A corresponding value is determined for each non-root node in a tree-defined path between a root node and a particular non-root node based on a weight W of the corresponding non-root node, a cumulative weight C1 of all descendants of the corresponding non-root node, and a cumulative weight C2 of all descendants of a parent of the corresponding non-root node. A product of all values corresponding to non-root nodes in the tree-defined path between the root node and the particular non-root node is determined. A region having an angular width and a radial width each based on the product is provided to represent the particular non-root node.