nominalattribute.java

数据挖掘。数据仓库

package org.scut.DataMining.Core;

import java.util.Date;
import java.util.HashMap;


public class NominalAttribute extends MiningAttribute {

	/** map for nominal value to integer value */
	private HashMap<String,Integer> nominalMap;
	
	public NominalAttribute(String name) 
	{
		super(name);
		// TODO Auto-generated constructor stub
		this.nominalMap = new HashMap<String,Integer>();
	}
	/**
	 * Gets the count of the nominal string
	 * @return count of the nominal string,-1 if numeric type encountered
	 */
	public int getNominalCount()
	{
		return this.nominalMap.size();
	}
	/**
	 * Maps a nominal string to interger value
	 * @param nom nominal string to be maped to an integer value
	 * @return interger value of the nominal value in the map, -1 if not found
	 */
	public int getNominalValue(String nom)
	{ 
		Integer value = this.nominalMap.get(nom);
		if(value == null) return -1;
		return value.intValue();
	}
	/**
	 * Adds a nominal string to the map, if exists nothing changed
	 * @param nom new nominal string
	 */
	public void addNominal(String nom)
	{
		if(this.nominalMap.containsKey(nom)) return;
		this.nominalMap.put(nom,this.nominalMap.size());
	}
	/*********************************************************************/
	public static void main(String[] args)
	{
		long start = new Date().getTime();
		NominalAttribute nom = new NominalAttribute("Hong");
	    nom.addNominal("A");
	    nom.addNominal("B");
	    nom.addNominal("C");
	    System.out.println(nom.getName());
	    System.out.println(nom.getNominalCount());
	    System.out.println(nom.getNominalValue("B"));
		long end = new Date().getTime();
		System.out.println("Time eclipsed[s]: " + (end-start)/1000.0);
	}
	/*********************************************************************/
	
}