For trees of unknown depth we must sometimes use recursive routines to extract data. We have such a file in yahoo.xml which, as you might imagine, could be pretty deep.
The function walkover takes a node n as input. The other parameter x gives the depth of the node. We visit each node, then visit each if the children in turn. This is a "pre-order" walk. We visit the parent before we visit the children.
This time the
s parameter builds up the path of the node so far.
Cosmologyare given as the id attributes for the corresponding nodes. Use this to create linked words. Like this