In this tutorial, we will learn about the followings;

Apriori candidates generations, self-joining and apriori pruning principle.

Apriori Candidates generation:

Candidates can be generated by following activities;

Step 1:

self-joining

Example of self-joining

V W X Y ZX={V W X,    V W Y,    V X Y,    V X Z,    W X Y}Self-joining = X * XV  W X Y from V W X and V W YV X  Y  Z from V X Y and V X Z

So frequent candidates are V  W X Y  and V X  Y  Z

Step 2: 

Apriori pruning principle:

Example of Apriori pruning principle

V W X Y ZX={V W X,    V W Y,    V X Y,    V X Z,    W X Y} According to Apriori Pruning principle V X Y Z is removed because V Y Z is not in X. 

So frequent candidate is V W X Y