/**
* Copyright (C) 2001-2017 by RapidMiner and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapidminer.com
*
* This program is free software: you can redistribute it and/or modify it under the terms of the
* GNU Affero General Public License as published by the Free Software Foundation, either version 3
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
* even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License along with this program.
* If not, see http://www.gnu.org/licenses/.
*/
package com.rapidminer.operator.learner.associations.fpgrowth;
import com.rapidminer.operator.learner.associations.Item;
import com.rapidminer.tools.Tools;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
/**
* This is the basic data structure for {@link FPGrowth}.
*
* @author Sebastian Land
*/
public class FPTree extends FPTreeNode {
private Map<Item, Header> headerTable;
public FPTree() {
super();
headerTable = new HashMap<Item, Header>();
children = new HashMap<Item, FPTreeNode>();
}
/**
* This method adds a set of Items to the tree. This set of items has to be sorted after the
* frequency of the contained items. This method should be used to add Items of a transaction or
* a treepath to the tree. The frequency of the set is represented of weight, which should be 1
* if items are gathered from transaction
*
* @param itemSet
* the sorted set of items
* @param weight
* the frequency of the set of items
*/
public void addItemSet(Collection<Item> itemSet, int weight) {
super.addItemSet(itemSet, headerTable, weight);
}
public Map<Item, Header> getHeaderTable() {
return headerTable;
}
@Override
public String toString(String abs, int recursionDepth) {
StringBuffer buffer = new StringBuffer();
buffer.append(abs);
buffer.append("+ ROOT");
buffer.append(Tools.getLineSeparator());
for (FPTreeNode node : children.values()) {
buffer.append(node.toString(abs + " ", recursionDepth));
}
return buffer.toString();
}
public String printHeaderTable(int recursionDepth) {
StringBuffer buffer = new StringBuffer();
for (Item item : headerTable.keySet()) {
buffer.append(item.toString());
buffer.append(" : ");
buffer.append(headerTable.get(item).getFrequencies().getFrequency(recursionDepth));
buffer.append(Tools.getLineSeparator());
}
return buffer.toString();
}
}