Homework 2
1. Implementing Apriori algorithm (using either C++ or Java). Your program should be able to accept two parameters with input: filename and a minimal support level. For instance, “myapriori filename 15”, where “myapriori” is the execution file, and 15 means a frequent itemset has frequency of 15% of the entire transactions in “filename”. The file format is as follows: each line corresponds to a transaction (no transaction id) and each item in the transaction is separated by a space. Your program should output all the frequent itemsets in the input file with the specified minimal support level. [70 points]
a) A detailed Pseudo code including the necessary data structure for implementation [20 points];
b) Source code [40 points], and;
c) The running results (screen captures) of the following input file and minimal support (10%, 20%, 30%, 50%) [10 points].
1 2 3 4
1 4 5 6
2 3 4
1 2 3 4
2 3 6
1 2 4 6
4 5
1 2 3 4 5
3 4 5
1 2 3 6
1 2 3 5
1 4 5
2 3 4 6
1 2 3 4
2 3 4
1 2 4 5 6
3 4 5
1 2 3 4 5 6
3 4 5 6
1 2 3 5
2. Given 4 items, A, B, C, and D, list all possible itemsets in a lattice. [10 points]
3. In the following transaction database, if the minimum support is 7, please list all frequent itemsets and their support counts. [20 points]
TID
Transactions
100
{A, B, E}
200
{B, D}
300
{A, B, E}
400
{A, C}
500
{B, C}
600
{A, C}
700
{A, B}
800
{A, B, C, E}
900
{A, B, C}
1000
{A, C, E}
4. In Question 3 above, please answer the following questions:
(a) draw the lattice of all itemsets (with their support counts) [10 points];
(b) Given minimal support 5, list closed and maximal frequent itemset(s) [10 points].18
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