This slideshow gives an example of Apriori algorithm

1. Modern College of Arts, Science & Commerce Ganeshkhind Pune-16.
Department of Computer Science
Data Mining Assignment
THE APRIORI ALGORITHM
EXAMPLE
Presented by
Ms. Gunshri Patil gunshrisp4955@gmail.com
Ms. Divya Chavda divyachavda429@gmail.com
Ms. Dhanshree Hande dhanshreehande2157@gmail.com
Ms. Madhuri Patil patilmadhuri4488@gmail.com
Guided by
Dr. Dipali Meher
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2. Q. Perform Apriori Algorithm to Find Frequent Patterns
with Minimum Support=2.
 Given Dataset:
Tid Items
1 A,B,C,D
2 A,B,D
3 A,D
4 A,C
5 B,C
6 B,D
7 A,C,D
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3. Step-1:Calculating C1(Candidate set)
Minimum Support=2
Dataset D
C1
C1
TID Items
1 A,B,C,D
2 A,B,D
3 A,D
4 A,C
5 B,C
6 B,D
7 A,C,D
Itemset Support Count
{A} 5
{B} 4
{C} 4
{D} 5
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4. Step-2:Now, we will take the itemsets that have the Minimum
Support(2).it will give us the table L1(frequent itemset)
C1 L1
L1
Itemset Support Count
{A} 5
{B} 4
{C} 4
{D} 5
Itemset Support Count
{A} 5
{B} 4
{C} 4
{D} 5
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5. Step-3: Candidate Generation C2, and L2:
C2 L2
Itemset
{A,B}
{A,C}
{A,D}
{B,C}
{B,D}
{C,D}
Itemset Support Count
{A,B} 2
{A,C} 3
{A,D} 4
{B,C} 2
{B,D} 3
{C,D} 2
L2
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6. Step-4: Candidate generation C3, and L3:
L3 will have only one combination, i.e., {A, C, D}.
C3 L3
 Frequent itemset ={A,C,D}
Itemset Support Count
{A,B,C} 1
{B,C,D} 1
{A,C,D} 2
{A,D,B} 0
Itemset
{A,C,D}
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7. THANK YOU
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