ATCdata                 nodes of the ATC hierarchy
[,atctree-method        find a subset of the tree
atctree                 constructor for atctree objects
atctree-class           class to represent a tree from the ATC
                        hierarchy
cutting,atctree-method
                        cutting from an ATC tree
drugnames               display drug name for ATC codes
parents                 show the parents of the specified node(s)
plot,atctree-method     plot the tree as a network graph
pruning,atctree-method
                        prune an ATC tree
show,atctree-method     summarise atctree object
treelevs,atctree-method
                        helper functions for atctrees
