【摘要】 随着数据库规模的增加或支持度阈值的减少,频繁模式的数量将以指数形式增长,FP-growth算法运行的时空效率将大为降低.本文提出一种基于格的快速频繁项集挖掘算法LFP-growth,算法利用等价关系将原来的搜索空间(格)划分成若干个较小的子空间(子格),通过子格间的迭代分解,将对网格P(I)的频繁项集挖掘转化为对多个子格的并集进行的约束频繁项集挖掘.实验结果和理论分析表明,在挖掘大型数据库时,LFP-growth算法的时间和空间性能均优于FP-growth算法.更多还原

【Abstract】 Along with the increasing size of database and the reduction of support threshold,the number of frequent patterns will grow exponentially,and the time and space efficiency of the FP-growth algorithm will greatly reduce.The cause of low efficiency was analyzed,and according to the analysis,a lattice-based algorithm for fast mining frequent itemsets(LFP-growth)was presented.The proposed algorithm divided a large lattice into many sub-lattices by using equivalence relation.Through iterativing decomposition of sublattices,frequent itemset mining in lattice was transformed into frequent itemsets mining in a union set of multiple sublattices.Experiments have shown that the time and space performance of LFP-growth algorithm is superior to that of FP-growth algorithm in mining large database.更多还原