/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.commons.math.stat.clustering;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

/**
 * Cluster holding a set of {@link Clusterable} points.
 * 
 * @param <T>
 *            the type of points that can be clustered
 * @version $Revision$ $Date$
 * @since 2.0
 */
public class Cluster<T extends Clusterable<T>> implements Serializable {

	/** Serializable version identifier. */
	private static final long serialVersionUID = -3442297081515880464L;

	/** The points contained in this cluster. */
	private final List<T> points;

	/** Center of the cluster. */
	private final T center;

	/**
	 * Build a cluster centered at a specified point.
	 * 
	 * @param center
	 *            the point which is to be the center of this cluster
	 */
	public Cluster(final T center) {
		this.center = center;
		points = new ArrayList<T>();
	}

	/**
	 * Add a point to this cluster.
	 * 
	 * @param point
	 *            point to add
	 */
	public void addPoint(final T point) {
		points.add(point);
	}

	/**
	 * Get the points contained in the cluster.
	 * 
	 * @return points contained in the cluster
	 */
	public List<T> getPoints() {
		return points;
	}

	/**
	 * Get the point chosen to be the center of this cluster.
	 * 
	 * @return chosen cluster center
	 */
	public T getCenter() {
		return center;
	}

}
