Decision Tree Constructing System Based on Design Patterns

Abstract

基于决策树构造算法 ID3和C4.5,可衍生出诸多的算法变种.本文据此提出了决策树构造系统设计过程中的“热点”问题,对“热点”问题的不同处理方式即为算法的变种.同时应用设计模式来逐一解决这些问题,这样,保证了所得的决策树构造系统具有良好的可扩展性和可复用性,可适应多种算法的变种.Decision tree is an important way of classification in Data Mining.Decision tree has some basic algorithms,such as ID3 and C4.5.CART and PUBLIC algorithms are two important algorithms.Comparing these algorithms,we can know that there are some local changes affecting the construction of decision tree.This paper concludes a lot of“hot spots” in decision tree algorithm,such as data extracting,decision tree constructing,missing value handling,test attributes criterion selecting,decision tree pruning and decision tree describing,which include the local changes in algorithm fore mentioned and the design that should have good extensibility.Design patterns are experiences of software developments and designs.Applying design patterns to handle“hot spots”,the designs and codes of decision tree constructing system only revises little when these“hot spots”changed.Thus,this paper applies design patterns to design decision tree constructing system.Obviously,this solution has good extensibility and reusability