store frequent itemset information.

store frequent itemset information. The difference between the
T-tree and other set enumeration tree structure is
1. Array is used to define the levels in each sub-branch of the
tree which permits “indexing in” at all levels which in turn
offers computational advantages.
2. To make the indexing at all levels the tree is built in
“reverse”. Here, each branch is founded on the last element of
the frequent sets to be stored.
The most significant overhead when considering ARM data
structures is that the number of possible combinations
represented by the item-columns in the input data scales
exponentially with the size of the record. A partial solution is to
store only those combinations that actually appear in the data
set. The implementation of this structure can be optimized by
storing levels in the tree in the form of arrays, thus reducing the
number of links needed and providing direct indexing. For the
latter purpose, it is more convenient to build a “reverse” version
of the tree, referred to as a T-tree, the Total support tree. In the following table 2, frequent itemsets and rules were produced
using different approaches and different parameter settings.