apriori algorithm - Data mining algorithm

apriori algorithm - Data mining algorithm

• 1.
  Dr.Divya K S KristujayantiDeemed to be University
• 2.
  APRIORI ALGORITHM
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  Step-1: Calculating C1and L1: Steps in detail Step-1: K=1 • Create a table containing support count of each item present in dataset –Called C1(candidate set) • compare candidate set item’s support count with minimum support count. This gives us itemset L1.Here it is > 4
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  Step-2: K=2 • Generatecandidate set C2 using L1 (this is called join step). Condition of joining Lk-1 and Lk- 1 is that it should have (K-2) elements in common. • Check all subsets of an itemset are frequent or not and if not frequent remove that itemset. • Now find support count of these itemsets by searching in dataset. • compare candidate (C2) support count with minimum support count this gives us itemset L2. • Continue this process until no frequent itemsets are found further
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  • Step-2: CandidateGeneration C2, and L2:
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  • Step-3: Candidategeneration C3, and L3:
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  • Step-4: Findingthe association rules for the subsets:
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  Find the minimumsupport count (%)
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  Valid