Closed patterns and max-Patterns A long pattern contains a combinatorial number of sub- patterns e.g,{a…,a1o0 contains(10)+(10)+…+ (100)=20-1=1.27*1030 sub-patterns Solution: Mine closed patterns and max-patterns instead An itemset X is closed if X is freguent and there exists no super-patternY x, with the same support as X (proposed by pasquier, et al. ICDT99) An itemset X is a max-pattern if X is frequent and there exists no frequent super-pattern y X(proposed by Bayardo SigMOd98) Closed pattern is a lossless compression of freq. patterns Reducing the of patterns and rules February 4, 2021 Data Mining: Concepts and Techniques 7February 4, 2021 Data Mining: Concepts and Techniques 7 Closed Patterns and Max-Patterns ◼ A long pattern contains a combinatorial number of sub￾patterns, e.g., {a1 , …, a100} contains (100 1 ) + (100 2 ) + … + (1 1 0 0 0 0 ) = 2 100 – 1 = 1.27*1030 sub-patterns! ◼ Solution: Mine closed patterns and max-patterns instead ◼ An itemset X is closed if X is frequent and there exists no super-pattern Y כ X, with the same support as X (proposed by Pasquier, et al. @ ICDT’99) ◼ An itemset X is a max-pattern if X is frequent and there exists no frequent super-pattern Y כ X (proposed by Bayardo @ SIGMOD’98) ◼ Closed pattern is a lossless compression of freq. patterns ◼ Reducing the # of patterns and rules