/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2008 by Rapid-I and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapid-i.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.example.set;

import java.util.Iterator;

import com.rapidminer.example.Attribute;
import com.rapidminer.example.Example;


/**
 * This ExampleReader skips all examples containing attribute values that are
 * not a number.
 * 
 * @author Ingo Mierswa, Simon Fischer
 * @version $Id: SkipNANExampleReader.java,v 2.6 2006/03/21 15:35:39 ingomierswa
 *          Exp $
 */
public class SkipNANExampleReader extends AbstractExampleReader {

	private Iterator<Example> reader;

	private Example currentExample;

	public SkipNANExampleReader(Iterator<Example> reader) {
		this.reader = reader;
		this.currentExample = null;
	}

	public boolean hasNext() {
		if (currentExample == null) {
			while (reader.hasNext()) {
				Example e = reader.next();
				if (!containsNAN(e)) {
					currentExample = e;
					return true;
				}
			}
			return false;
		} else {
			return true;
		}
	}

	public Example next() {
		hasNext();
		Example dummy = currentExample;
		currentExample = null;
		return dummy;
	}

	private boolean containsNAN(Example e) {
		for (Attribute attribute : e.getAttributes()) {
			if (Double.isNaN(e.getValue(attribute)))
				return true;
		}
		return false;
	}

}