Top 10 classic algorithms for data mining (4) the Apriori algorithm.

========================================================== ========================================================

This series is reprinted from aladdina

The aim is to give a general introduction to the top ten typical algorithms of Data Mining. If you need to study these algorithms in depth, please visit the internet. ========================================================== ==========================================================

 

The Apriori algorithm is the most influential algorithm used to mine frequent item sets of Boolean association rules. Its core is a recursive algorithm based on the two-phase frequency set thinking. This association rule belongs to single-dimension, single-layer, and boolean association rules in classification. Here, all the item sets with a higher degree of support than the minimum level are called frequent item sets.

 

The prefix statistics used by the algorithm include:

• Maximum number of rule objects: Maximum number of objects contained in the rule object group
• Minimum support: the minimum number of cases that must be met by the object or object group in the rule
• Minimum confidence level: the minimum confidence level threshold that computing rules must meet

The basic idea of this algorithm is: first, find all frequency sets. The frequency of these item sets is at least the same as the predefined minimum support. Then, strong association rules are generated by the frequency set. These rules must meet the minimum support and minimum trust level. Then, use the frequency set found in step 1 to generate the expected rules and generate all rules containing only the items in the set. Each rule has only one rule on the right, the rule definition is used here. Once these rules are generated, only those rules that are greater than the minimum credibility given by the user are left. The recursive method is used to generate all frequency sets.
A large number of candidate sets may be generated, and the database may need to be scanned repeatedly. These are two major disadvantages of the Apriori algorithm.