apriori.ItemSet.java Source code

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Here is the source code for apriori.ItemSet.java

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/*
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package apriori;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.PrintStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.TreeSet;
import org.apache.commons.lang.builder.HashCodeBuilder;

/**
 *
 * @author darius
 * @param <T> ItemSet type
 */
public class ItemSet<T> {

    private TreeSet<T> _sortedItems;
    private ArrayList<T> _items;
    private Integer _support;

    public ItemSet() {
        _sortedItems = new TreeSet<>();
        _items = new ArrayList<>();
        _support = 0;
    }

    public ArrayList<ItemSet<T>> getKMinusOneSubsets() {
        if (_items.size() <= 1)
            throw new UnsupportedOperationException("Cannot get subsets for 1-itemsets");
        ArrayList<ItemSet<T>> subsets = new ArrayList<>();
        for (int i = 0; i < _items.size(); i++) {
            ItemSet<T> subset = new ItemSet<T>();
            for (int j = 0; j < _items.size(); j++) {
                if (j == i)
                    continue;
                subset.add(_items.get(j));
            }
            subsets.add(subset);
        }
        return subsets;
    }

    public ArrayList<T> toList() {
        return _items;
    }

    public boolean contains(ItemSet<T> rv) {
        return _items.containsAll(rv._items);
    }

    @Override
    public boolean equals(final Object rv) {
        if (this == rv)
            return true;
        if (rv == null)
            return false;
        return _items.equals(((ItemSet<T>) rv)._items);
    }

    @Override
    public ItemSet<T> clone() {
        ItemSet<T> theClone = new ItemSet<>();
        //Sorted items
        theClone._sortedItems = new TreeSet<>();
        Iterator<T> treeIter = this._sortedItems.iterator();
        while (treeIter.hasNext()) {
            theClone._sortedItems.add(treeIter.next());
        }
        //Items
        theClone._items = new ArrayList<>();
        Iterator<T> listIter = this._items.iterator();
        while (listIter.hasNext()) {
            theClone._items.add(listIter.next());
        }
        theClone._support = this._support;
        return theClone;
    }

    public int getSupport() {
        return _support;
    }

    @Override
    public int hashCode() {
        // Two randomly chosen prime numbers
        HashCodeBuilder hasher = new HashCodeBuilder(17, 31);
        for (T item : _items) {
            hasher = hasher.append(item);
        }
        return hasher.toHashCode();
    }

    public int size() {
        return _items.size();
    }

    public void add(T elem) {
        _sortedItems.add(elem);
        _items.add(elem);
    }

    public void incrementSupport() {
        _support++;
    }

    public void print(BufferedWriter output) throws IOException {
        String s = "Item: " + _sortedItems.toString() + ", Support: " + _support.toString();
        output.write(s);
        output.newLine();
    }

    public void setSupport(int newVal) {
        _support = newVal;
    }

}